pump motors

A.O.
A
.O. SMITH
SM ITH
A.O.Smith
Motor
Mastery
University
PUMP
MOTORS
APPLICATION
INCLUDES:
SWIMMING POOLS
SPA & JETTED TUB
MAINTENANCE
INSTALLATION
REPAIR
TROUBLESHOOTING
OTHER MODULES INCLUDE:
HEATING, VENTILATION,
AIR CONDITIONING &
REFRIGERATION MOTORS
GENERAL PURPOSE MOTORS
SPECIAL PURPOSE MOTORS
NOTICE:
The information contained in this booklet is general in nature and is drawn from sources believed to
be reliable. It is intended for general information purposes only. The descriptions in this booklet
may not apply to a particular motor or a particular application. No warranties are intended to be
created by this information.
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Motor Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Nameplate Information . . . . . . . . . . . . . . . . . . . . . . . . . .4
Cross Referencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . .11
eMod® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
eMod® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Electrical Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Component Checks . . . . . . . . . . . . . . . . . . . . . . . . . . .33
eMod® Technical Support . . . . . . . . . . . . . . . . . . . . . . .37
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Impeller Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Bearing Replacement . . . . . . . . . . . . . . . . . . . . . . . . .48
Start Switch Installation
and Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
© 2006 A.O. Smith Corporation
1
Pump Motors
Introduction
Welcome to A.O. Smith’s line of Swimming Pool
and Spa Pump motors. This manual is designed for
one purpose – to make it simple for you to install,
maintain, troubleshoot and service A.O. Smith pool
and spa motors. All you need are a few basic tools
and some helpful hints - the kind that appear
throughout this booklet.
We’ve included all the information we think you
will need to solve the most common pump motor
problems encountered out in the field. This easy to
read manual contains great illustrations and diagrams for quick reference. Mastering the concepts
in this manual will allow you to add the kind of
value to your service that your customers will recognize and appreciate.
WARNING! This is not a guide for the do-ityourselfer. These tips and suggestions are offered
for persons with the proper qualifications and necessary test equipment.
Replacements for every application. Every now
and then you probably come across a motor that’s
beyond repair. When you do, remember that A.O.
Smith manufactures replacement pool and spa
motors for practically every application you’ll ever
encounter in the field. So save yourself some time
and effort and just ask for A.O. Smith or A.O. Smith
Century ® motors first – at any A.O. Smith distributor or dealer. A.O. Smith motors are as rugged as
you will find, but keep in mind that all motors need
service or maintenance at one time or another.
A.O.Smith
2
Pump Motors
Installation
This section is divided into five parts. The first is
Motor Types followed by Nameplate Information.
The third is Cross-referencing followed by
Installation Guidelines. The last is eMod® Installation.
It is designed to help you select the correct motor for
an application and install it properly.
Motor Types
There are five distinct electrical designs that are
commonly found on swim pool and spa pumps.
1.
Split Phase. This type of single-phase motor is
used extensively in spa and jetted tubs and
above ground pool applications. Some are used
on pumps on the lower end of the in ground
pool market. This design has a start winding
and a start switch, but no capacitors.
2.
Capacitor Start. This is a very common singlephase motor found on in ground pool pump
applications. The starting torque is higher
(150-175% of full load) and starting current
lower than the split phase equivalent. The
operation is similar to a split phase in that there
is a start switch to take the start winding and
capacitor out of the circuit once the motor
reaches 2/3 to 3/4 of full speed.
3.
Permanent Split Capacitor. This design does
not have a start switch and is often referred to
as a “switchless” motor. It uses a run capacitor
that remains in the circuit at all times. The PSC
design has significantly less starting torque
than the capacitor start design.
A.O.Smith
Pump Motors
4.
Capacitor Start/Capacitor Run. This design is
used to increase efficiency in run mode. Both
start and run capacitors are used. In run mode,
PSC and Cap. Start/Cap. Run motors are the
same.
5.
Three phase (Polyphase). This is the simplest,
most efficient design. Its use is limited to
commercial and industrial applications because
three phase power is not available in residential
areas.
3
A.O.Smith
4
Nameplate
Information
Pump Motors
When you need information about the motor
you are replacing, you’ll always be able to find it
printed on the motor nameplate. On A.O. Smith
motors the nameplate is usually found on the side
of the motor. Shown below are sample pool motor
nameplates. As you read the nameplate, refer to the
guide so that you can understand the meaning of
each item that the manufacturer provides about
its motor. Remember also that your dealer or
distributor can help you choose the correct
replacement motor.
A.O.Smith
Pump Motors
5
AMB: The maximum ambient (surrounding)
temperature in which a motor is designed to operate.
It is shown in degrees Celsius rather than Fahrenheit.
Amps: Amps is the electrical current flowing through
the conductors at rated load, rated voltage and rated
frequency. Pool motors have service factor amps on
the nameplate. This is amps at horsepower times
service factor load and is the maximum acceptable
current the motor should use.
Catalog Number: (“CAT”). This number indicates
that the motor is a stock rating, readily available from
standard inventory as a replacement motor.
Code: This is the NEMA code letter that specifies
locked rotor kVA per HP (volts multiplied by locked
rotor amps, divided by 1000 times rated HP). It is
used to determine the correct size breaker needed in
the electric box.
ENCL (Enclosure): Enclosure refers to the openings
or lack of openings in the shell and end frames.
Motors are either open or enclosed. There are
different categories within each. Pool motors are
usually open “dripproof”.
FR (Frame): The Frame identifies the mounting
and shaft configuration. It does not indicate the
diameter of the shell.
Centurion and Centurion SE motors have a 6 1/2”
diameter shell. Flex 48 and A.O. Smith two compartment motors have a 5 5/8” diameter shell. Either
diameter can be 56C or 56J. That is because the shaft
configuration and mounting holes are the same on
both shell diameters. Square Flange motors, usually
signified as 56Y or 48Y, mount the same regardless
of the shell diameter. Square Flange motors are not
recognized by NEMA, National Electrical
Manufacturer’s Association, so there are
A.O.Smith
6
Pump Motors
no consistent frame size designations for them.
However, Square Flange is an industry standard and all
swim pool Square Flange motors mount the same. Note:
A water systems manufacturer uses a square flange
motor with a special shaft. Water system motors should
never be used on swim pool applications.
HP (Horsepower): Conventional unit of measurement
for power (One horsepower equals 746 watts output).
HZ: (Hertz): Measurement of frequency, equaling cycles
per second of alternating current. The United States has
60 hertz current.
Insul Class (Insulation Class): This is the temperature
rating of insulation used in the construction of the
motor. Most pool and spa motors use class “B” or class
“F” insulation.
Part or Mod Number: This identifies the motor’s
specific design by part number. All motors have a model
number. Only catalog motors have a catalog number.
PH (Phase): Denotes whether the motor operates on
single-phase AC current or three phase AC current.
Rotation (Rot): Rotation is the direction the shaft turns.
Almost all swim pool pump motors turn counterclockwise when looking at the motor from the end where the
pump is located. This can be referred to as CCWPE.
Impeller Rotation
RPM (Revolutions per minute): RPM is how many
times the shaft makes one complete revolution in one
minute at rated horsepower, voltage and frequency.
Serial: The serial code indicates the plant of
manufacture and the date of manufacture. Each manufacturer is different. A.O. Smith has an explanation of the
date code inside the front cover of the motor catalogs.
A.O.Smith
Pump Motors
7
SF (Service Factor): Service factor is a multiplier
that when multiplied by the horsepower of the
motor indicates the total permissible horsepower
loading that may be carried when the motor is
operating at rated voltage and frequency.
TIP: The most important thing to remember when
replacing a motor is that the replacement motor’s
horsepower times its service factor must be equal to
or greater than the original motor’s horsepower
times it’s service factor.
Time: Time indicates the duty cycle of the motor.
Pool and spa motors are rated for continuous duty.
Type: This is a code for the electrical design of the
motor. For example, A. O. Smith uses “CX” to identify its PSC switchless design. Other codes are “CS”
for capacitor start; “SP” for split phase and “UAK”
for capacitor start/capacitor run. Be sure to check
with your dealer or distributor, because each
manufacturer’s type codes are different.
Volts: Voltage is the required electrical potential
applied to the motor. It is the force that moves the
current in an electrical conductor. Single phase Pool
and Spa motors will be 115, 230 or dual voltage,
115/230 volt. Dual voltage motors are usually
connected for 230 volt at the factory because if 115
volts are applied incorrectly in the field the motor
will just hum or run slowly, get hot and trip on the
overload. This does not harm the motor. If the
motor was connected for 115 volt at the factory and
230 volts were mistakenly applied the motor will
burn out immediately.
A.O.Smith
8
Pump Motors
Motors are designed to run at plus or minus 10% of
the nameplated voltage. A motor nameplated 230
volts will run from 207 to 253 volts. However, at
207 volts the motor amps will be slightly higher
and the Rpm’s will be slightly lower.
Some motors are rated 208-230 volts. These motors
will operate in a range from 208 volts minus 10% to
230 volts plus 10% or 187 volts to 253 volts.
TIP: Occasionally 200 or 208 volt motors are used.
If a motor that has been designed for 200 volts or
208 volts is not readily available you can
use a 230 volt motor with the next higher
horsepower. For instance, a 1Hp 230 volt motor
can replace a 3/4 HP 200 volt motor.
TIP: There are no energy savings when connecting
the motor to 230 volts versus 115 volts or vise versa.
The advantage to the higher voltage is you can use
smaller wire to connect the motor to the service and
it reduces light flicker or dimming when the motor
starts.
Warning Labels: Make sure you read and understand all the warning information on the motor.
Always TURN THE POWER OFF before working
on a pool or spa motor.
Wiring Diagram: On or near the nameplate is a
schematic of how to connect the motor to the power
source, change the voltage (if applicable), change
the rotation (if applicable) or connect for different
speeds (if applicable). When installing a replacement motor make sure the motor is connected for
the same voltage as the power source.
A.O.Smith
9
Pump Motors
The nameplate of the motor being replaced
contains much of the critical information needed to
select a new motor. Some of the nameplate data
detailed in the previous section is repeated below in
order to reemphasize its importance when choosing
a replacement motor
Cross
Referencing
Choosing the right replacement motor is easy
using these 5 steps:
1.
Know the end frame you need. Is it:
Thru Bolt
5.146 Bolt Circle
Thru Bolt
5.812 Bolt Circle
C-Face Keyed
56C Frame
C-Face Threaded
56J Frame
2.
Know the total horsepower output.
Find the horsepower and service factor on the
nameplate of the motor to be replaced. Multiply
the horsepower times (x) the service factor. The
result is the “total horsepower” of the motor.
Do the same for the possible replacement
motors. Select the replacement motor that has a
total horsepower (horsepower times the service
factor) that is equal to or greater than that of
the original motor’s total horsepower
3.
Is the original motor single or three phase?
The original and replacement motors must be
the same unless the power supply is being
changed.
Square Flange
A.O.Smith
10
Pump Motors
4.
What is the correct voltage?
The operating voltage of the replacement motor
must be capable of operating on the same voltage as the original motor.
TIP: If the original motor was dual voltage (115/230
volt) and an equivalent dual voltage replacement is
not readily available, a single voltage motor (115
volt motor or a 230 volt motor) of the actual voltage
being used at the installation may be used.
5.
What is the motor’s cycle or hertz?
As a general rule, 50-cycle motors should not be
substituted for 60-cycle motors and vice versa.
Your distributor or dealer is also a great resource
for determining what replacement motor you need.
In addition motors can be cross-referenced on the
A.O. Smith web site www.aosmithmotors.com.
A.O.Smith
11
Pump Motors
When replacing a motor that has failed, if possible,
determine the cause of failure. If you know why the
original motor failed you may be able to improve the
installation so the new motor doesn’t fail for the same
reason. Be particularly conscious of external conditions such as moisture, low voltage or dirt and debris
that could have contributed to the failure. Here are
more things you should consider when installing a
motor:
Installation
Guidelines
Heat The number one enemy of a motor is heat.
Overheating always results whenever there is a lack
of clean, continually circulating air through a motor.
Heat can damage a motor’s windings, insulation,
bearing lubricant and capacitors. In short, heat can
quickly decrease the service life of a motor. Remember
that proper ventilation is always a crucial consideration when installing a motor.
If at all possible, install a motor in a location that is
free of dirt, dust or airborne debris, such as leaves.
Indoors is best, but not in areas with high humidity,
such as a laundry room or shower area. If the motor is
installed outdoors, try to choose a shady spot that’s
protected from leaves and grass clippings. If you
cover the motor to protect it from possible debris or
water, there must be enough room between the cover
and the motor to allow for a continual supply of unrecirculated outside air to flow through the motor.
A.O. Smith single-phase pool and spa motors feature a thermal overload protector that will shut down
the motor if it overheats. As the windings begin to
cool down, the overload protector will automatically
re-start the motor. Blocked ventilation or an overload
condition can cause the motor to shutdown on a
repeated basis. The motor is operating as it was
designed. It is important to determine what is causing
the motor to overheat and correct the problem.
A.O.Smith
12
Pump Motors
TIP: In situations where the ambient
temperature is exceptionally hot, utilizing a high
efficiency E-Plus or Conservationist motor in place
of a standard efficient motor can prevent the
overload protector from nuisance tripping.
Moisture A.O. Smith motors have superior
resistance to moisture, but you should avoid
placing the motor where it can be splashed. Avoid
installing the motor in low spots that could flood or
under roof overhangs where gutters could overflow
during heavy rains. Avoid locating the motor in the
highest humidity area. It is best to elevate the
motors at least two inches from the ground.
Power source Before you turn the motor on,
check to see that the line voltage, phase and
frequency match the specifications shown on the
motor nameplate. Current capacity must be
adequate enough to maintain rated voltage at the
motor terminals under all conditions. If it’s too
high, contact your local utility. If it is too low check
for overloaded circuits, loose connectors or wire of
the wrong gauge (see wire selection guide).
Altitude Generally, motors will run hotter with
increasing altitudes. For installations more than
3,300 feet above sea level, it’s advisable to use a
motor with the next larger horsepower rating than
the one recommended for that application at sea
level or use an E-Plus or Conservationist (high
efficiency) motor of the same rating.
Mounting Fastening the motor to the pump and
the pump and motor assembly securely to a foundation or base, will prevent vibration, loosening
and future misalignment. Make sure that the motor
and pump assemblies rotate freely before starting
the motor.
A.O.Smith
13
Pump Motors
Electrical connections The
wiring diagrams shown on the
motor make wiring your motor
easy. Make sure the connections
are tight to prevent failure or
overheating.
Grounding Always make sure the motor is
properly grounded before applying power. In
addition to the green grounding screw inside the
motor, which grounds the motor to the service
ground, every pool and spa motor has a bonding
lug. The bonding lug is on the outside of the motor
and is used to bond the motor and all other
conductive surfaces together to prevent a potential
difference between the surfaces. Grounding should
be done in compliance with all local and national
electrical codes.
Wire Size Incorrect voltage at the motor
terminals can cause the motor to overheat. It’s a good
idea to check the electrical supply wires to confirm
that the wire size is sufficient to carry the required
voltage. For example, if you’re using a 1 HP motor at
115 volts over a distance of 150 feet use #8 wire. If the
motor is being installed to operate on 230 volts, #10
Pump Motor Recommended Wire Size
DISTANCE FROM SERVICE ENTRANCE/MAIN PANEL TO MOTOR
Motor
H.P.**
50 feet
115V
100 feet
150 feet
200 feet
230V
115V
230V
115V
230V
115V
230V
1/3
14
14
12
14
10
12
8
12
1/2
14
14
10
14
8
12
8
10
3/4
12
14
10
12
8
12
6
10
1
12
14
8
12
8
10
6
8
1-1/2
10
14
8
12
6
10
6
8
2
10
14
8
10
6
10
6
8
3
12
10
8
8
*Always follow all applicable codes.
**Pump Motors with service factors greater than 1, and split phase designs.
No more than 15 volts drop at start, in worst case.
A.O.Smith
14
Pump Motors
wire is sufficient for the 150 feet distance. Larger wire
sizes reduce the voltage drop to the motor in both the
start and run modes. A lower voltage drop means the
motor will run more efficiently (cooler) and have
increased service life.
Pump Seal Always install a new seal when
reassembling a pump or installing a replacement
motor. A leaking pump seal may cause a motor to
fail very quickly. To best protect the motor, A.O.
Smith recommends the use of a Sintered Carbon
Graphite Seal.
It is important that the pump seal be installed
correctly. The following are installation instructions
provided courtesy of U. S. Seal Mfg.
1.
Disassemble pump cavity to expose defective
seal. Removal of old seal and assembly of new
seal requires careful operations and precautions.
Caution: Lapped and polished faces of
new seal are easily scratched and damaged. PROTECT FROM DAMAGE, DIRT
and FINGERPRINTS.
2.
Carefully remove old seal head and seat taking
care not to scratch shaft or seat counterbore.
NOTE HOW THE OLD SEAL IS ASSEMBLED,
TO BE SURE REPLACEMENT SEAL IS
INSTALLED IN IDENTICAL MANNER.
3.
Clean shaft and counterbore surfaces using fine
emery cloth or equivalent. Remove rust, burrs
and wipe clean.
A.O.Smith
15
Pump Motors
4.
Shaft, seat counterbore and rubber members of
seal head and seat should be lubricated with a
lubricant compatible with the seal elastomer.
Check seals surfaces to be sure they are free of
any dirt, grit or lubricants.
5.
Press seal seat firmly into counterbore to be sure
it is bottomed square. SLIDE SEAL HEAD
ALONG SHAFT MAKING SURE THAT SPRING
IS CORRECTLY ENGAGED INTO SEAL.
6.
Re-assemble pump and remember that trouble
free operation of a pump includes a correct seal
installation.
TIP: If the pump has been run dry long
enough for the plastic pump to overheat,
consider replacing the pump also.
Overheating can cause the pump to warp
making it impossible for the pump seal to
prevent leaking.
Additional Protection. Do not remove the water
slinger (washer) from the shaft. It helps deflect
water away from the motor bearing.
Overview
The eMod load sensing electronic module is an
accessory to a pool pump motor. It is permanently
attached to the motor and is used to protect the
motor and pump from damage. eMod is SVRS
compliant per ASME A112.19.17-2002 for suction lift
applications.
eMod®
The load sensing module can turn the pool pump
motor off if the input power to the motor is too low,
indicating either a lack of fluid flow, or a dry running pump. It can also turn the motor off if the
input power gets too high, indicating excessive load
A.O.Smith
16
Pump Motors
on the pump. The module can also shut the pump motor
off if input current is too high, indicating a locked rotor or
blocked pump impeller condition.
eMod Set Up
The eMod module is permanently mounted and wired to
the motor. All necessary electrical connections are made
at the factory.
Basic Operation
While the pool pump is running, the eMod module monitors pump motor input power. If the motor input power
drops 10% below its normal running condition value for
more than 1 second, the eMod will fault and the pump
motor will be turned off. When faulted, the eMod module
will flash the red LED on the end of the enclosure.
If the motor input power increases more than 12% over its
normal running condition value for more than 4 seconds,
the eMod will fault and the motor will be turned off. If
either of the out of normal conditions does not last for the
required amount of time, however, the fault condition will
not be latched, and the motor will continue to run.
Startup Lockout Time
Often times when starting a pool pump, there is air in the
plumbing system. If the volume of air is large, it can take
a minute or two to fully evacuate the air in the system
and prime the pump. To keep the eMod module from
detecting a low input power condition (lack of flow) a
startup lockout period is employed. When the eMod is
powered up, it will ignore the motor power input for
up to 3 minutes before it starts to monitor the motor
A.O.Smith
Pump Motors
17
operating conditions. While the eMod module is in this
startup lockout state, the green LED on the end of the
enclosure will flash.
If the pump primes faster than the 3 minute limit, the
eMod circuitry will detect this and immediately go into
running mode. When in run mode, the green LED on the
end of the enclosure will be on.
Calibration
Because every pool is hydraulically different, the eMod
module must be individually calibrated to each pool
installation. The unit will automatically calibrate after
running through the 3 minute priming period for the first
time. When calibrating the unit, it is important to make
sure that the pump is fully primed, and that all valves
and filters are in their normal operating conditions. Also
make sure that there are no leaves or other obstructions
on the pool drains. This will result in the pump motor
input power being at its normal operating value.
During the three minute startup lockout time, the green
and red LEDs will flash alternately. The alternate flashing LEDs indicates that the eMod unit is in auto-calibrate
mode. At the end of the three minute priming period,
the eMod will automatically calibrate and go into run
mode (green LED on).
If for some reason the pump is not yet fully primed, let
the eMod unit fault out. Cycle input power and press
the Reset button as discussed below.
Note: It is important that the pump be fully primed and
running at normal conditions when the eMod unit is
calibrated.
Note: For two speed motors, the eMod must be calibrated at both operating speeds. It is recommended that the
eMod be calibrated at both speeds when the motor is
initially installed on the pool, and the motor is still cool.
A.O.Smith
18
Pump Motors
Test of Proper Calibration
Upon completing the installation of an eMod equipped motor
to the pump and pool plumbing, and after calibration is
complete, the manufacturer recommends that the unit be
tested for proper function. This can be accomplished by
either blocking the inlet of the drain or closing a main valve.
The motor and the pump should shutdown in less than 10
seconds of this action. The red LED on the eMod unit should
also be flashing. Remove the blockage or return the valve to
the original position and the unit should begin functioning
again in approximately two (2) minutes. It is recommended
that this test be performed monthly to assure no changes
have occurred in the calibration the pool system.
If the eMod unit does not shutdown the motor and pump in
less than 10 seconds, the unit should be Reset. Please refer to
the Reset section of the installation guide. Once the unit is
Reset, the unit will then calibrate to the new load point once
power is applied to the unit. The blockage test should be
repeated once the unit has completed the calibration and is
operating with a solid green LED illuminated.
Reset
If for some reason it becomes necessary to reset the calibration of the eMod module (change in plumbing or other pool
conditions), press the button next to the red LED on the end
of the enclosure and hold it down for at least three seconds.
Please note that this function is only active during the first
three minutes of operation after the power is applied. This
will erase the calibration memory and the motor will stop.
Cycle power to the unit (wait 10 seconds with the power off
to allow the internal power supply to reset). The unit will
now go through a new auto-calibration period and then
establish new values for motor input power and current, as
was discussed in the calibration section above.
A.O.Smith
Pump Motors
19
Bypass Mode
It may be necessary to defeat the eMod motor input
power monitoring functions during unusual operating
conditions in the pool. This might include hand wand
vacuuming the pool, back flushing of filters or replacement of filters, or clearing a large volume of air from
the pool plumbing system.
To enter Bypass mode, press and hold the Bypass
mode button for at least three seconds. The Bypass
mode button is located next to the green LED on the
end of the enclosure. The eMod will respond by
starting to blink the red LED with the green LED on.
Bypass mode will last for 30 minutes, or until the
Bypass mode button is pushed for at least three seconds a second time. If at any time during the cleaning
process the power is cycled off, the Bypass mode
button must be pressed again once the power is cycled
back on, otherwise the unit believes that cleaning has
been completed and has returned to normal operation
mode. If the unit stops during any cleaning activity,
cycle the power off, wait 10 seconds, power on,
and press the Bypass mode to continue cleaning
operations.
Caution: Bypass mode defeats the pump monitoring
functions of the eMod. While in Bypass mode, there is
no protection from a drain blockage suction condition
or dry running pump.
A.O.Smith
20
Pump Motors
Maintenance
As with a car or any other mechanical device, periodic maintenance is required to keep an A. O. Smith motor
operating properly. While the motor itself does not
often need attention, providing the proper environmental conditions around the motor can be the key to a long
service life. Conditions change. It is important to monitor and correct any situation that might cause damage
to the motor.
Motors
Moisture Water leaks from pump seals or pipe joints
should be repaired to prevent failure of bearings and
insulation. DO NOT splash or spray the motor. Mount
the motor away from low spots and damp areas, and
take measures to protect it from windblown rain.
Cooling Provide for ample air circulation around
motor. If an external motor cover is used, be certain it
does not trap moisture and has enough space between
the motor and the cover to allow fresh air to circulate
through the motor. Clean the air inlets as required,
making sure that the POWER IS OFF first.
TIP: A running motor that is too hot to touch is not
necessarily overloaded. Class B insulated motors
have a maximum operating temperature of 130
degrees Centigrade (266 degrees Fahrenheit). If the
automatic protector is not tripping and the actual
running amps do not exceed the maximum amps on
the nameplate, the motor is not overheating.
Seasonal Whenever the motor must be shut down for
extended periods, be sure all surfaces, vents and interiors are dry to prevent rust. If the motor is kept outdoors, cover it to prevent debris such as blowing leaves,
dirt and snow from clogging the inlets. DO NOT SEAL
THE MOTOR IN PLASTIC OR OTHER AIRTIGHT
WRAPPINGS because condensation may form on the
inside damaging bearings and insulation.
A.O.Smith
Pump Motors
21
TIP: When restarting the pump and motor after
an extended down time, make sure the suction
is flooded so the pump seal is wet. Starting the
motor with a dry pump seal can damage the
seal.
Cleaning In general, the inside of the motor
should not need cleaning if proper safeguards are
made against contamination by dirt, lint or sand. If
you want to clean the outside, simply use a damp
cloth. Don’t spray the motor with a water hose.
Flooding the motor can cause permanent damage.
Lubrication The ball bearings in A.O. Smith
motors are double sealed permanently lubricated. If
it appears the bearings have failed, simply replace
them.
TIP: Noisy bearings are the first sign of bearing
failure. If the bearings are not replaced promptly,
the motor can overheat causing the windings to
fail. Bearing noise is often a sign that the pump
seal has been leaking. Always change the pump
seal when you change the bearings.
Chemicals Do not store or use chemicals close to
the motor.
Dirt Avoid sweeping or stirring dust near the
motor while it is running.
A.O.Smith
22
Pump Motors
eMod
®
Operating Fault
If a fault occurs while the eMod is in the running mode,
the motor will be turned off and the red LED will flash.
After two minutes, the module will attempt to re-start the
motor. After the three minute startup lockout, or if the
circuit senses that the pump is primed, the unit will once
again start monitoring motor input power. If conditions are
still not normal, the unit will fault out again. The eMod
will attempt to restart like this four times. After the fourth
attempt, the module will go to lockup mode. In lockup
mode the red LED will be on. The only way to get out of
lockup mode is to cycle power to the motor.
Faults that the eMod will attempt to recover from are:
•
Motor input power too low
•
Motor input power too high
•
Motor current too high
•
Motor temperature too high
•
Power line voltage too low
•
Circuit power supply fault
•
Momentary loss of power
If the motor runs normally for at least nine minutes when
the eMod returns to run mode, the fault counter will be
reset back to zero. This means that it will now require five
new faults to reach lockup mode again.
A.O.Smith
Pump Motors
23
Fault Mode
If the eMod faults and goes immediately to a steady red
LED condition, this means the fault that was detected was
critical, and the eMod went to lockup mode. The only
way to get out of lockup mode is to cycle power to the
motor.
The faults that are considered critical are:
•
Power line voltage too high
•
Ambient temperature too low
•
Microprocessor fault
•
Reset switch is stuck closed
•
Bypass mode switch is stuck closed
The eMod performs a self check of its electronic circuits
on startup. If upon application of power to the eMod, it
immediately goes to the fault condition, it is likely faulting
on a failure of one of these circuits. Allow 15 or 20 minutes for the circuitry and motor to cool down if excessive
running temperature is suspected. If the fault will still not
clear, the eMod system will need to be replaced.
The self check faults include:
•
Circuit power supply fault
•
Ambient temperature too low
•
Microprocessor fault
•
Software fault
•
Line voltage sense circuitry not working
•
Motor current sense circuitry not working
•
Motor control relays stuck
A.O.Smith
24
Pump Motors
LED Indicator Map
Green LED
Red LED
Operating Mode
On
Off
Run Mode
Flashing
Off
Priming Mode
Off
Flashing
Non-Critical Fault
(circuit will attempt restart)
Off
On
Lockup Mode
(cycle power to attempt restart)
Alternate Flashing
Alternate Flashing
Calibration Mode
Flashing Together
Flashing Together
Reset Mode
On
Flashing
(cycle power to restart motor)
Bypass Mode
A.O.Smith
25
Pump Motors
eMod Load Sensing Module Specifications
Input Power
Voltage
102 to 130 vac rms single phase (low voltage connected)
195 to 250 vac rms single phase (high voltage connected)
Frequency
58 to 62 hertz **
Power Consumption
5 Watts maximum (eMOD only)
Line Loss Ride Through
20 milliseconds minimum
Environment
Operating Temperature Range
14 to 122 °F (-10 to 50°C)
Storage Temperature Range
-15 to 150 °F (-25 to 65°C)
Humidity
10 to 95% non-condensing
Altitude
5000 feet maximum
Shock / Vibration
1G maximum (any axis)
Enclosure
Length
5.4 inches
Width
3.5 inches
Depth
2.6 inches
Weight
1 pound
Other
drip and splash proof
Other
UL / CSA Compliance
tested to UL 60730-1A
FCC compliance
tested to CISPR11 Class B
ASME A112-19.17 – 2002
SVRS Suction Lift Compliant
**Note: 50 Hz operation will result in incorrect timing. The eMod is rated for only 60
Hz operation at the present time.
A.O.Smith
26
Pump Motors
Troubleshooting
There is not a single listing of motor trouble shooting pro c e d u res to be followed in a given ord e r. The
pro c e d u res will differ depending on the situation.
As with anything dealing with electricity, personal
safety is of prime concern. Before you even touch
the motor, MAKE SURE THE POWER IS OFF.
Always turn the power off at the electric service
fuse or breaker box. To prevent electrical shock, use
a meter to check for electrical shorts and be sure
the motor is securely grounded and bonded in
conformity with local codes. Do not work on
electrical devices if water or moist conditions are
present and cannot be avoided.
If the motor is not operating pro p e r l y, refer to the
following:
Checklist
Motor fails to start (makes no sound)
•
Check the obvious first. Are the power switch
and timer on?
•
Check for blown fuse or circuit breaker. If fuses
are used be sure fuses are the proper size or type.
•
WITH THE POWER OFF, check all connections
on the terminal board. Verify they are correct by
consulting the wiring diagram on the motor.
Make sure all connections are tight including
the ground wire.
•
Check the voltage at the terminal board after
first turning the power back on. Be sure to
TURN THE POWER BACK OFF after completing this step. Note: Voltage at motor terminals
should be + or – 10% of the voltage on the
nameplate. If the voltage is high, contact the
local Power Company. If the voltage is low
check the wire size of the power line from the
electric box to the motor.
A.O.Smith
Pump Motors
•
Check for overloading from other appliances on
the same circuit as the motor.
•
Inspect motor windings for continuity.
•
Protector tripped – wait until the motor cools
down then restart – check protector for
continuity
27
Motor starts but shuts down (thermal overload
protection)
•
Check the voltage at motor terminal. If it is too
high call the local Power Company.
•
Check amperage. If high, find out if the pump
impeller was recently replaced (it could be sized
i n c o r rectly). Remember, motor horsepower
times the service factor = total horsepower. Total
horsepower must be equal to or greater than the
impeller rating. Check for overloads.
Noisy Motor
•
Check motor coupling, brackets and other
attached parts. Tighten loose nuts, bolts or set
screws.
•
Turn shaft. If it is rough or tight, check bearings
•
Look for loose or binding parts inside the motor
or the pump.
•
Pump cavitation
Overheating (smoking or cycling)
•
Check the motor’s ventilation by looking for
clogged air vents or openings. Clean away all
dirt and leaves or other debris from around the
motor.
•
Check internal cooling fan. Is it intact and
operating pro p e r l y ?
A.O.Smith
28
Pump Motors
•
Compare connections to wiring diagram. Make sure
motor is connected correctly for applied voltage.
•
Low or high voltage. Voltage should be + or – 10% of
nameplated voltage. If it is higher that +10% call the
local power company. If lower than –10% of the
nameplated voltage check wire size from the service
fuse box or circuit bre a k e r. If the voltage is low from
the service use a motor one increment higher in
horsepower or an E-plus or Conservationist high eff iciency motor of the same horsepower and service
factor.
T I P: Electric demand on the power company
varies. If the motor is nuisance tripping because of
low voltage it may only trip during the part of the
day when electrical usage is the highest. Do your
voltage checks at that time of day.
•
High ambient temperatures. Pool motors are usually
designed to operate in 50 degree C ambients (122
degrees Fahrenheit). Artificially high ambients can
occur if a motor operates in a confined space and recirculates the same air or circulates air from another
motor next to it.
•
Check amp draw. If the amps are higher than nameplate amps but the voltage is acceptable, WITH THE
POWER OFF, inspect the motor and the pump for
mechanical obstructions that could cause an overload.
•
Look at motor windings and capacitors for damage
or signs of shorting. Check for continuity.
•
Application overload. In cases of flooded suction or
positive pre s s u re on the inlet side of the pump, flow
may be increased overloading the pump.
A.O.Smith
Pump Motors
•
Misapplication. Make sure the motor is not
undersized. Remember that total horsepower is
horsepower times service factor. The total
horsepower must be equal to or greater than
the pump/impeller rating.
•
Check the motor start switch and governor (if
applicable) to make sure it is adjusted properly
and is operational.
This section explains how to use test equipment.
Conventional Multimeter or Ohmmeter
29
Test Equipment
An ohmmeter can be used to measure the
resistance of the various motor windings as well
as to test the insulation. The ohmmeter will have
numerous ranges from R x 1 where the meter reads
directly in ohms, to a Rx100K where the actual
meter reading must be multiplied by 100,000 for
the actual ohm value.
Before using an ohmmeter:
•
Make sure the power is off.
•
Read the instruction manual for the meter.
•
All troubleshooting checks specify the ohmmeter range to be used. If your meter does not
have the exact range, use the next higher range.
A.O.Smith
30
Pump Motors
Digital Ohmmeter/Multimeter
Direct reading digital ohmmeters are readily
available in the field. To use this type:
•
Make sure the power is off.
•
Read instruction manual for the meter.
•
You do not have to set the ohmmeter to a particular scale as the meter displays the ohm value
up to maximum capability of the meter.
•
Install probes and take resistance readings in the
normal manner.
Ammeter and Voltmeter
Voltmeter Readings:
Install leads in bottom of ammeter. Select the
desired voltage scale. Take readings by touching
one probe to each of the lead line terminals.
Ammeter Readings:
•
Arrange leads so the jaws of the ammeter will
encircle one lead.
•
Set meter on maximum amp scale and encircle
jaws around one lead and take reading. It may
be necessary to reset to a lower scale.
A.O.Smith
31
Pump Motors
Voltage Check
•
Make sure power is off.
•
Determine motor voltage and set meter
•
Reconnect power
•
Start the motor
Electrical
Checks
Caution: All wires are live (hot) so use
extensive care.
Touch one probe to L1 and the other to L2.
Voltage reading to be within 10% of nameplate
voltage, i.e. between 207 and 253 volts for a motor
nameplated 230 volts.
If no voltage is recorded, check fuses, circuit
breakers, timers, wiring, etc. for open connection
or broken wires.
If voltage is outside the acceptable limits, check
for adequate wire size. Look for loose terminals
and connections or pitted contacts. Check pump
disconnect switch.
Check voltage at service entrance. If not within
plus or minus 10% contact power company.
A.O.Smith
32
Pump Motors
Amperage Check
•
Make sure power is off.
•
Set ammeter scale based on Max. Load amps.
•
Position one line lead (L1 or L2) so that the jaws
of ammeter can encircle one power lead. (It will
usually be necessary to install a test loop to
have room for the meter jaws.)
•
Make sure switch and governor are free of
obstructions (if applicable).
•
Reconnect power
•
Start the motor
Caution: All wires are live (hot) so use
extensive care.
•
Take a reading. The value should not exceed
maximum load amps (service factor amps) on
the motor nameplate.
Excessive amps means an overloaded condition
or incorrect voltage applied. Problem could also be
a short in the motor.
A.O.Smith
33
Pump Motors
Perform the following checks to confirm that each
component is functioning properly.
Ground Check
•
Turn the power off.
•
Set ohmmeter to R x 1K.
•
Attach one probe to ground screw on the end
frame and touch the other probe to all terminals
on the terminal board, switch, capacitor and
protector. A reading of less than 10K could indicate a ground. New motors typically read over
one megohm. Old motors with dust, dirt and
moisture could show resistance to ground below
10K and still run satisfactorily. A cleaning may be
in order. Readings may vary from day to day
depending on humidity levels. Approximately
25K at 115 volts will trip the ground fault device.
Keep in mind the ground fault device is seeing
the total leakage of all loads on the circuit. GFI’s
normally trip on readings from 4 to 6 milliamps.
•
If grounded, check all external leads for cuts,
breaks, frayed wires, etc. Replace damaged leads
and recheck for grounds and proper lead routings, Make sure replaced leads are not pinched
between canopy or cover and end frame. If
ground is in the stator, the motor must be
replaced.
Component
Checks
Start Switch Check (if applicable)
•
Visual Checks
1. Make sure power is off.
2. Remove Canopy
•
Discharge capacitor by touching the two
terminals simultaneously with the blade of an
insulated handle screwdriver.
A.O.Smith
34
Pump Motors
•
Make sure there are no obstructions preventing the
proper operation of the rotating governor. Check
wiring and make sure none of the leads are in the area
of the governor where they can be cut or interfere with
the governor. Check governor for proper operation
and make sure flipper moves freely.
•
Check switch contacts for severely burned or pitted
contacts, sticking etc. Some blackening or pitting is
normal after the motor has been used. Replace switch
if there is any doubt. DO NOT try to repair the switch
by bending the contact blades.
•
The switch contacts in motors are plated and should
never be sanded which would remove the plating and
cause early failure. They may be cleaned by wiping the
contacts with a piece of cardboard or paper bag.
•
Attach one lead to each terminal of the switch.
Ohmmeter reading should be 0. With one lead on each
terminal, flip governor weight to the run position.
Reading should be infinity.
•
Reconnect power
•
Start the motor. Visually check the action of the switch
and governor. Switch contacts must be closed when
motor is at rest and should open when the motor
reaches about 2/3 of full load speed.
TIP: Replace the capacitor and switch at the same
time. A defective switch usually stresses the start
capacitor.
Winding Continuity
For typical two compartment, single phase, dual voltage
only, capacitor start, single speed motor, connected for 230
volts. Set meter to R x 1.
(For single voltage motors, check between L1 and L2.)
A.O.Smith
35
Pump Motors
Disconnect one of the red leads to the switch. Discharge capacitor by
shorting across the terminals with the blade of an insulated handled
screwdriver. Take the following ohm readings.
L2 & A
A & YELLOW
Resistance between L2 and A must be the same as resistance between
A and Yellow.
YELLOW TO RED
L2 TO RED
Yellow to Red (winding side of switch) must be same as L2 to same
Red terminal.
A.O.Smith
36
Pump Motors
Protector (Thermal Overload) Check
•
Set ohmmeter to R x 1.
•
Resistance between terminals:
1 & 2 should be approximately 0 (Disc.)
2 & 3 should be approximately 0 (Heater)
•
Replace if either value exceeds 1 ohm.
TIP: Motor cycling on overload indicates some
other problem not just a defective overload.
Capacitor Check (Start or Run)
•
Set ohmmeter at Rx 1K.
•
Slip a heavy piece of paper between points on
the switch.
•
Discharge capacitor by touching the two
terminals simultaneously with the blade of an
insulated handle screwdriver
•
Attach one probe to each terminal. Ohmmeter
needle should move rapidly to right then slowly drift to the left. (Low ohm reading to high
ohm reading.)
•
If digital meter is used, readings should start
low and rapidly increase to maximum value.
•
Replace capacitor if bad.
TIP: The replacement capacitor must be the
same MFD as the original. However, if the
same voltage rating is not available it is
acceptable to use the next higher voltage.
Example; if a 370 volt unit is not available,
use the next rating, 440 volt.
A.O.Smith
37
Pump Motors
eMod®
eMod Technical Support Questions and Answers
Symptom:
My eMod equipped motor nuisance trips
(and has never run correctly).
Possible Problem:
The motor is configured for the wrong input power line voltage.
Solution:
Verify what the line voltage to the pool pump motor is with an AC voltage meter. If
the line voltage is in the range of 110 and 120 volts, the motor should be configured
for low voltage. If the line voltage is in the range of 208 to 240 volts, it should be
configured for high voltage. Change the motor configuration with the voltage selector
switch, or by moving wires on the motor terminal board as necessary.
Possible Problem:
The motor rotor or pump impeller is jammed.
Solution:
Remove power from the motor, and then remove the rear cover from the motor. Verify
that the motor shaft turns freely by inserting a screwdriver into the slot on the end of
the shaft, or by gently turning on the governor switch assembly with your hand. If the
motor shaft does not turn freely, it will be necessary to separate the pump and the
motor so that it can be determined which of the two is binding. If the motor is binding, it will need to be returned. If the pump is binding, verify that the pump parts
were assembled correctly, and that all parts are in good condition.
Possible Problem:
Power line wiring is insufficient for the motor load.
Solution:
Measure the voltage on the motor terminal board with an AC voltage meter when
power is applied and the motor is making the humming sound. If the voltage sags
below 85 volts for 115 volt systems, or below 190 volts for 240 volt systems, there is
too much resistance in the wiring to the motor to start reliably. A stronger electrical
supply to the pump motor will need to be provided.
Possible Problem:
The eMod equipped motor is calibrated to the wrong motor load point.
Solution:
Follow the instructions in the Un-Calibrate section of this manual.
A.O.Smith
38
Pump Motors
Symptom:
When I plug the hose to my suction cleaner in, the eMod equipped
motor faults out.
Possible Problem:
Air in the cleaner hose is being drawn into the pump. This causes the pump to
temporarily lose prime. The eMod detects this and shuts the pump off.
Solution:
Use the water flow from the return line to the pool to chase the air out of the suction
cleaner hose before plugging it in. This will keep the pump from losing prime when
you plug the hose in.
Allow the eMod to go through its reset period of two minutes. It will then restart the
pump and try for three minutes to re-establish pump prime. This is usually enough
time to clear the air out of the lines and return to normal operating conditions.
A.O.Smith
39
Pump Motors
Symptom:
My eMod equipped motor used to run fine, but now seems to fault a lot.
Possible Problem:
Skimmer basket, strainer basket, or main drain in pool is plugged with debris.
Solution:
Verify that the baskets and drains are clear and clean if necessary.
Possible Problem:
Filter needs to be cleaned.
Solution:
Check the pre s s u re gauge on the filter. If the pressure has gone up more than 5 PSI
from where it was when the filter was clean, the water flow through the system may
be reduced enough to cause the eMod to fault. Clean the filter if necessary. If the filter
is a sand type filter, back-flush if necessary.
Possible Problem:
Not enough water in pool to cover the skimmer.
Solution:
Pump is drawing air into the system because the skimmer is not covered in water. The
air causes the pump to partially lose prime and this causes the eMod to fault out. Add
water to the pool if necessary.
Possible Problem:
Diverter valve(s) that choose return lines from pool to pump are in wrong position.
Solution:
Check to verify that diverter valve(s) are in the position that they were when the
eMod was first installed and calibrated. Return valve(s) to the original position if
necessary. If it is desired to operate the pool with a new valve position as the “new”
normal position, please recalibrate the eMod. Instructions on how to do this are
located in the Un-Calibrate section of this manual.
A.O.Smith
40
Pump Motors
Symptom:
My two speed pump runs OK on high speed, but faults on low speed after
running several hours.
Possible Problem:
Leak in plumbing system causes pump to lose prime. In high speed mode the pump
moves enough water to absorb the air being leaked into the system. In low speed
mode, however, the water flow is reduced to the point where the air bubbles
accumulate in the strainer basket. Eventually the air bubble becomes large enough
that the pump loses prime.
Solution:
Check to see that the strainer basket cover is tight, and the gasket is in good condition.
Check the diverter valve(s) to make sure that it is in good condition and that the seals
in it are in good condition. Check any unions in the piping system for proper fit up
and that the O-ring seal is in good condition.
Symptom:
The eMod runs for less than one second when power is applied and then quits.
Possible Problem:
Failed relay on the eMod board. Each time the motor is powered up, the electronics
checks the motor control relays to verify that they are working properly. If one of the
relays is stuck shut, the motor will run for 1/2 to 1 second before the eMod electronics
realizes that something is wrong and turns the motor off.
Solution:
The eMod equipped motor will need to be replaced.
A.O.Smith
41
Pump Motors
Symptom:
My eMod equipped motor nuisance trips (and has never run correctly).
Possible Problem:
The eMod mis-calibrated when system was first set up.
Solution:
Sometimes the pump has a hard time clearing all the air from the pool return lines in
the three minute window allowed by the eMod to do this. If this seems to be the case,
follow the instructions in the Un-Calibrate section of this manual.
Possible Problem:
Air leak in the pool plumbing system.
Solution:
Check the water flow in the strainer basket of the pool pump. If there is a heavy flow
of air bubbles in the water, or if the strainer basket never fills with water, there may be
an air leak in the suction side plumbing to the pump. Check to see that the strainer
basket cover is tight, and that the gasket is in good condition. Check the diverter
valve(s) to make sure that it is in good condition and that the seals in it are in good
condition. Check any unions in the piping system for proper fit up and that the O-ring
seal is in good condition. Check for cracked pipes.
Possible Problem:
Pump/motor is too large for pool plumbing system.
Solution:
Check the water flow in the strainer basket of the pool pump for a heavy flow of air
bubbles in the water. How does the pump sound? If it is making lots of noise, similar
to the sound of a car tire on a gravel road, the pump is cavitating. There are both signs
that the pump is trying to move more water than the pool plumbing is capable of
delivering. Common causes of plumbing flow restrictions are long runs of small
diameter pipe, too many elbows or valves, or the pump being located too high above
the water level of the pool. If a change to the plumbing cannot be made to rectify the
limit to water flow, the best solution would be to try a smaller pump/motor
combination.
A.O.Smith
42
Pump Motors
Symptom:
My eMod equipped motor nuisance trips (and has never run correctly).
Possible Problem:
Suction release valve of SVRS not adjusted correctly.
Solution:
If a mechanical type suction release valve is located upstream of the pump, it may be
bleeding air into the system. Adjust the release setting on the valve to keep a tighter
seal during normal running conditions.
NOTE: If any adjustment is made to the SVRS device protecting a pool, its proper
operation should be verified before allowing swimmers back in the pool. See the
operator’s manual for the SVRS device in question for the proper procedure on how
to do this.
A.O.Smith
Pump Motors
43
Symptom:
When I apply power to my pump motor, the eMod immediately displays a solid
red light. The motor doesn’t even attempt to start.
Possible Problem:
Voltage applied to the motor is out of the allowable operation range.
Solution:
Measure the voltage on the motor terminal board with an AC voltage meter when
power is applied. If the voltage is not between 102 and 130 volts for 115 volt systems,
or between 195 and 250 volts for 240 volt systems, the supply voltage is outside the
allowable range for the motor. Check the voltage at other locations in the house to see
if they are within normal limits. If other circuits are OK, inspect the wiring of the pool
pump branch circuit. If all the house voltages are out of limits, contact the local power
utility.
Possible Problem:
Temperature of the eMod electronics is too high or too low. The rated temperature of
operation for the eMod and pump motor is from 14˚F (-10˚C) to 122˚F (50˚C).
Solution:
If the temperature is around 14˚F (-10˚C), the pump may be in danger of freezing up.
If the pool water is heated and just the pump motor is cold, a method of keeping the
eMod and motor at a more moderate temperature will need to be provided.
A.O.Smith
44
Pump Motors
Symptom:
When I apply power to my pump motor, the eMod immediately displays a solid
red light. The motor doesn’t even attempt to start.
Possible Problem:
Temperature of the eMod electronics is too high or too low. The rated temperature of
operation for the eMod and pump motor is from 14˚F (-10˚C) to 122˚F (50˚C).
Solution:
If the temperature is around 120˚F (50˚C), wait until a cooler part of the day to see if
the motor will now run again. If temperatures this hot are seen regularly, providing
shade from the sun for the eMod and pump motor will give more reliable service.
Also check to see that the cooling holes around the bottom of the motor are free of
o b s t ructions and debris.
Possible Problem:
Internal fault in the electronics.
Solution:
If voltage temperature issues can be discarded, it is likely an internal fault in the eMod
electronics that is causing the problem. The motor will need to be replaced.
Symptom:
When the power is applied to my eMod equipped motor, it runs for about 30
seconds and then stops. A solid red light is displayed.
Possible Problem:
The un-calibrate button or clean mode button is stuck.
Solution:
With the power to the motor off, try pushing the un-calibrate button and the clean
mode button several times. Also wiggle the rubber actuator back and forth in the
housing a little as occasionally the button gets hung up in the housing. Re-apply
power to the motor to see if this clears the problem. If not, the motor will need to be
replaced.
A.O.Smith
45
Pump Motors
Service
A. O. Smith pool and spa motors are built
tough, to run day after day without being serviced. When service is necessary serviceable parts
can be accessed quite easily. Whether it is the
A.O. Smith two compartment design with most
serviceable parts in the “control room” under the
rear canopy or the Century Centurion with externally mounted capacitor and
“switchless” design, installing new parts is easy and quick.
Motor
Assembly
All of the motors covered by this manual are similar in design and construction but may vary in type of protector, type of flange or electrical type. When
disassembling, make sure you note the exact location of all components so they
can be reassembled properly. This is especially true of the bearing assembly
where the number of small parts (rings, washers, etc.) could easily be assembled
incorrectly.
Make sure you note the position of all the lead wires on the terminal board
and where they are routed.
CENTURION
56 FRAME SQUARE FLANGE
POOL & SPA ASSEMBLY
A.O.Smith
46
Pump Motors
CENTURY
FLEX-48
POOL & SPA ASSEMBLY
TWO COMPARTMENT
56J FRAME
POOL & SPA ASSEMBLY
A.O.Smith
Pump Motors
47
When ordering parts refer to the catalog number
or model number and serial number on the motor
nameplate.
Impeller
Removal
All A.O.Smith motors have some method of
locking the shaft so the impeller can be removed.
Do not stick a screwdriver into the vent holes to
prevent the cooling fan from turning to lock up
the shaft. Some fans are plastic and will break.
Two compartment designs have a flat on the
shaft under the governor assembly. It can be
accessed by carefully sliding a 7/16” open-end
wrench under the protector at 12 O’clock until it
drops over the flats on the shaft.
Older Century Centurion models have flats on
the rear end of the shaft. Access to the flatted
portion of the shaft is achieved by removing a
small metal cover on the rear end frame with a
screwdriver.
Current Century Centurion models have a
plastic cover that can be removed by turning it
1/4 turn counterclockwise with a 15/16” wrench
and pulling out. The end of the flatted shaft
extends out from the rear of the motor. The shaft
can be locked using a 1/2” wrench .
Century Flex 48 motors have a screwdriver slot
or a hex hole (that requires a 5/16” hex socket
wrench) on the end of the shaft.
A.O.Smith
48
Pump Motors
Replacing a bearing in a motor is not a difficult task, provided you follow these set procedures. If a bearing is noisy or doesn’t run
smoothly, it should be replaced. If a bearing is
removed for any reason, it should be replaced
with a new one. If it’s necessary to replace one
bearing, replace the other as well to prevent
return service calls and pump down time.
Bearing
Replacement
Use only A.O. Smith bearings obtained from
A.O. Smith and ordered by the proper
A.O. Smith part number. Bearings obtained from
A.O. Smith are built with balls having a specific
fit, checked for sound level and filled with highgrade grease for the temperature and service
conditions. A.O. Smith bearings are lubricated
and require no further attention during their life.
Do not substitute. Do not reuse old bearings
pulled from shafts because this could damage
the motor and cause a return service call.
After the power has been shut off and the
motor disassembled from the pump follow these
steps:
Note: Disassemble the pump in
accordance with the pump manufacturer’s
recommendations.
1.
Mark the end frames and shell of the motor
with two pieces of tape or a marker so the
motor can be reassembled in the original
configuration.
A.O.Smith
49
Pump Motors
2.
Remove the rotor and shaft from the shell by:
(Century designs skip to 3.) For Two
Compartment design, remove the canopy.
Remove the switch to get access to the governor
on the end of the shaft. Remove governor
springs. Remove governor weight by spreading
the bracket with a screwdriver. Take out screw
on the end of the shaft and remove governor
bracket. (See section on “Switch Adjustment”
for instructions on how to set the switch when
the motor is reassembled.)
3.
Remove the four thru-bolts.
4.
Remove the end frame opposite the shaft by
putting a screwdriver in the notch and tapping
the handle of the screwdriver.
5.
Remove the shaft end frame, using the same
method. Carefully pull the rotor and shaft
assembly out of the shell from shaft extension
end. Be careful not to lose the washer and bearing load spring that is positioned in the bearing
bore in the end frame opposite the shaft extension. Be sure to replace the washer and spring
during re-assembly.
6.
Remove the bearing locking screws from the
shaft end frame.
Lock clip
NOTE: New motors do not have a lock plate.
They have a lock clip that is attached to the end
frame with a single screw. The screw is located
in one of the two holes that used to be used for
the lock plate screw. Turn the screw 1/2 turn to
release the bearing from the end frame.
A.O.Smith
50
Pump Motors
7.
Remove the shaft collars or snap
rings used to secure the bearings.
(You will need a pair of external ring
pliers).
8.
Use a bearing puller. (See“
Recommended Tools”) to remove
defective bearing(s).
9.
Install new bearing using a tube that
presses only on the inner race of the
bearing. (See “Bearing Information
Table” for size of tube that is
required.) Do not put pressure on the
outer race of the bearing. The bearing
will be damaged.
Re-assemble in the reverse order of the
disassembly instructions. If the motor is
a Two Compartment design make sure
you adjust the start switch correctly. (See
pages 35-36). Make sure there are no
leads in the area of the rotating governor.
When the canopy is installed make sure
no leads are pinched between the canopy
and end bracket.
Warning: Pinched wires or wires that
come into contact with the rotating
governor could cause a ground fault
that is very dangerous should power
be applied without the motor being
properly grounded.
For all designs, recheck wiring. Check
rotor and shaft to make sure it turns
freely by hand. Check motor for grounds
before applying power.
A.O.Smith
51
Pump Motors
BEARING INFORMATION TABLE
Bearing Dimensions
Bearing
Size
Diameter (Inches)
Inside
Outside
Width
A.O. Smith
Bearing
Part No.
(Inches)
203
.6693
1.5750
.470
604005-001
204
.7874
1.8504
.5512
100025-002
304
.7874
2.0472
.5906
603628-001
205
.9843
2.0472
.5906
603628-003
Bearing Installation Tube Dimensions
(In Inches)
Outer
Diameter
of Tube
Wall
Thickness
Minimum
Length
7/8
.095
3
1
.095
3
1-1/4
.125
3
RECOMMENDED TOOLS
BEARING PULLER SNAP-ON
TOOLS
MODEL NO. CG-250 OR EQUAL
TRU-ARC PLIERS
EXTERNAL RING PLIER
SNAP-ON TOOLS
MODEL NO. PRS 22 OR EQUAL
BEARING INSTALLATION TOOLS
Single Speed
•
In November 2001, A.O. Smith began producing
motors with a no-adjust switch. It is a one-piece
design eliminating the need for the “U” bracket.
The new switch needs no adjustment. Just
assemble to the end frame. Make sure the plastic
button is riding on the governor projection.
•
Older models use only one screw to secure and
adjust the switch. Very old models have two
screws. One to hold the switch in place and
one for adjustment.
Start Switch
Installation and
Adjustment
• Fasten switch snugly to end frame, through “U”
bracket with screw provided.
A.O.Smith
52
•
Pump Motors
A slight amount of switch movement is possible before the screw (s) are
tightened. Check to see that the switch button is centered over the governor
projection.
SWITCH ADJUSTING SCREW
—TIGHTEN ONLY—
PLASTIC BUTTON
START SWITCH
GOVERNOR PROJECTION
GOVERNOR WEIGHT
"U" BRACKET
REMOVE AND OPEN "U" BRACKET SLIGHTLY TO INSURE
SUFFICIENT SCREW TENSION WHEN INSTALLING NEW
SWITCH OR AFTER SCREW HAS BEEN LOOSENED.
.010”
.040”
MOTOR SHAFT
•
Reach in and move the governor weight (overcoming the spring tension)
until it touches the stops on the governor. The clearance between the
projection on the governor weight and the white button on the switch
should be .010” to .040” (.040 is about the thickness of paper clip wire).
•
When installing a new or used switch, the “U” bracket should be opened
slightly to insure sufficient tension against the screw. Tighten only when
adjusting. If the screw is loosened, it should be removed and the “U”
bracket should again be opened slightly.
•
Under no circumstances should switch contact blades be bent or deformed
in an attempt to obtain proper contact clearance.
2 Speed
Proper starting switch adjustment on two-speed motors is essential for
satisfactory operation and contact life.
•
Disconnect all power to the motor before attempting any repair. Repair
work should only be performed by a qualified electric motor technician.
•
Fasten switch snugly to end bell, through “U” bracket with switch
mounting screw provided.
•
A slight amount of switch movement is possible before the screw(s) are
tightened. Check to see that the switch button is centered over the
governor projection.
A.O.Smith
53
Pump Motors
•
Lift governor weight (overcoming spring tension) until it touches the stops
on the governor. Clearance between the governor projection and the switch
button should be .010” to .040 “.
•
Most newer models use only one screw to secure and adjust the switch.
When a new switch is installed, or an existing switch is being reinstalled,
the “U” bracket should be opened slightly to insure sufficient tension
against the screw. Tighten only when adjusting. If the screw is loosened, it
should be removed and the “U” bracket should again be opened slightly.
•
Under no circumstances should switch contact blades be bent or deformed
in an attempt to obtain proper contact clearance.
•
Once the governor weight is released and the governor projection pushes on
the switch button, contact “Z” should move away from the motor by
approximately .030”. This movement assures that the points will have sufficient contact, no matter what position the rotor/shaft and governor projection are in at rest.
•
In run position contacts “X” and “Y” must be open and contact “Z” closed.
At rest contacts “X” and ‘Y” must be closed and contact “Z” open.
2 SPEED SWITCH ADJUSTMENT
.010
.040
SWITCH ADJUSTING SCREW
—TIGHTEN ONLY TO OBTAIN
PROPER CLEARANCE—
CLEARANCE WHEN
ACTUATOR IS IN
RUN POSITION AS
SHOWN
SWITCH BUTTON
START CONTACTS
Y
Z
X
SWITCH ASSEMBLY
REMOVE AND OPEN "U" BRACKET SLIGHTLY TO INSURE
SUFFICIENT SCREW TENSION WHEN INSTALLING NEW
SWITCH OR AFTER SCREW HAS BEEN LOOSENED.
SWITCH MOUNTING “U” BRACKET
GOVERNOR ASSEMBLY SHOWN
IN OPEN POSITION
Other information valuable in servicing an Electric Motor can be found in the
Trouble Shooting section.
531 NORTH FOURTH STREET
TIPP CITY, OH 45371
937) 667-2431
FAX: (937) 667-5873
www.aosmithmotors.com
© 2006 A.O. Smith Corporation
Bulletin #3400
11/06
38
Pump Motors
Centurion®/SE/II
For motors manufactured in/after Nov., 1991 (Serial #BJ11)
Dual Voltage
Type CX-1⁄2 to 11⁄2 Hp
230/115 Volt
Switchless
HIGH VOLTAGE
LOW VOLTAGE
For motors manufactured in/after Nov., 1991 (Serial #BJ11)
Single Voltage
Type CX-11⁄2-5Hp
230 Volt
Switchless
EXTERNAL CONNECTIONS
A.O.Smith
39
Pump Motors
Centurion®
For motors manufactured prior to Nov. 1991. (Serial #BJ11)
Dual Voltage
Type CX–1⁄2 to 11⁄2 Hp
115/230 Volt
Switchless
EXTERNAL CONNECTIONS
Wiring Diagram #166359. Connection Label #166362.
For motors manufactured prior to Nov. 1991. (Serial #BJ11)
Single Voltage
Type CX–2, 3 & 4 Hp
230 Volt
Switchless
EXTERNAL CONNECTIONS
Wiring Diagram #166360. , 166361 Connection Label #166363.
A.O.Smith
40
Pump Motors
1081
115/230 Volt
INTERNAL WIRING
Type CS–1⁄2 to 11⁄2 Hp
Wishbone (Old Style)
EXTERNAL CONNECTIONS
Wiring Diagram #115242. Connection Label #115325.
115/230 Volt
INTERNAL WIRING
Type CP–2 Hp
Wishbone (Old Style)
EXTERNAL CONNECTIONS
Wiring Diagram #139691. Connection Label #115325.
A.O.Smith
41
Pump Motors
1081
230 Volt
INTERNAL WIRING
Type CP–3 Hp
Wishbone (Old Style)
EXTERNAL CONNECTIONS
Wiring Diagram #153477. Connection Label #115317.
115/230 Volt
Type CS–1⁄2 to 11⁄2 Hp
Single Arm Switch (Old Style)
LOW VOLTAGE
HIGH VOLTAGE
Wiring Diagram #157682. Connection Label #161035.
A.O.Smith
42
Pump Motors
1081
115/230 Volt
Type CP–2 Hp
Single Arm Switch (Old Style)
LOW VOLTAGE
HIGH VOLTAGE
Wiring Diagram #157683. Connection Label #161034.
E-Plus®
230 Volt
Type CX–2 and 3 Hp
Switchless (Old Style)
INTERNAL WIRING
EXTERNAL CONNECTIONS
Wiring Diagram #156228.
A.O.Smith
43
Pump Motors
2 Speed
115 Volt
INTERNAL WIRING
Type CSM–1⁄2 to 3⁄4 Hp
Wishbone (Old Style)
EXTERNAL CONNECTIONS
Wiring Diagram #157053. Connection Label #157187.
Type CSM–1 and 11⁄2 Hp
Wishbone (Old Style)
230 Volt
INTERNAL WIRING
EXTERNAL CONNECTIONS
Wiring Diagram #157061. Connection Label #157187.
A.O.Smith
44
Pump Motors
2 Speed
230 Volt
INTERNAL WIRING
Type CPM–2 Hp
Wishbone (Old Style)
EXTERNAL CONNECTIONS
Wiring Diagram #157057. Connection Label #157187.
Micro-Switch Motor
(Formerly identified as
Gould-Guard)
115/230 Volt
Type CS–1⁄2 to 1 Hp
(Old Style)
LOW VOLTAGE
HIGH VOLTAGE
Wiring Diagram #157891. Connection Label #157892.
A.O.Smith
45
Pump Motors
Switchless Motor
(Formerly identified as
Gould-Guard)
230 Volt
Type CX–11⁄2 HP
Switchless (Old Style)
HIGH VOLTAGE
Wiring Diagram #157663. Connection Label #157664.
(Formerly identified as
Gould-Guard)
230 Volt
Type CX–2 and 3 HP
Switchless (Old Style)
HIGH VOLTAGE
Wiring Diagram #157669. Connection Label #157664.
A.O.Smith
46
Pump Motors
Centurion®
Two-Speed
Single Voltage
115 Volt
Type CXPM–1⁄2 /.06 to 3⁄4 /.10 Hp
Solid-State Switch
EXTERNAL CONNECTIONS
Wiring Diagram #167174. Connection Label #167200.
Two-Speed
Single Voltage
230 Volt
Type CXPM–1/.12 to 2/.25 Hp
Solid-State Switch
EXTERNAL CONNECTIONS
Wiring Diagram #167201. Connection Label #167200.
A.O.Smith
47
Pump Motors
E-Plus® Switchless
Dual Voltage
115/230 Volt
Type CX–3⁄4 to 11⁄2 Hp
Switchless
EXTERNAL CONNECTIONS
Wiring Diagram #167985. Connection Label #166362.
Single Voltage
230 Volt
Type CX–2 and 3 Hp
Switchless
EXTERNAL CONNECTIONS
Wiring Diagram #167976. Connection Label #166363.
A.O.Smith
48
Pump Motors
Flex 48® Frame
Type SPM–3⁄4 /.10 HP
Two Speed Single Voltage
115 Volt
INTERNAL WIRING
EXTERNAL CONNECTIONS
Wiring Diagram #179679.
Two-Speed
Single Voltage
115 or 230 Volt
Type CXSM 11⁄2 /.18 HP
Type CXSM 2.0/.25 HP
through 4.5/.50 Spl HP
INTERNAL WIRING
EXTERNAL CONNECTIONS
Wiring Diagram #179859.
A.O.Smith
49
Pump Motors
Flex 48® Frame
Two-Speed
Single Voltage
115 or 230 Volt
Type CSM 1.0/.12 Hp 115 Volt
Type CSM 1.0/.16 Hp 115 Volt
Type CSM 1.5/.18 Hp 230 Volt
Type CSM 2.0/.25 Hp 230 Volt
INTERNAL WIRING
EXTERNAL CONNECTIONS
Wiring Diagram #179277.
Flex 48®
Single Voltage
115 Volt
WITHOUT AIR SWITCH
Type SP–1⁄2 to 11⁄2 Hp
WITH AIR SWITCH
Wiring Diagram #179085.
A.O.Smith
50
Pump Motors
SINGLE SPEED MOTOR — TYPICAL SCHEMATIC DIAGRAMS
Capacitor Start
Induction Run — Single Speed
EXT. & WIRE ROUTING
Dual Voltage — Single Speed — Capacitor Start
With Voltage Change Plug
NOTE: When the voltage
change plug is in the 115 volt
position, the black lead is on
the "L2" terminal and the
black/white tracer is on the
"A" terminal. When
the voltage change
plug is in the 230
volt position, the
black lead is in the
"A" terminal and the
black/white tracer is isolated.
A.O.Smith
51
Pump Motors
Capacitor Start
Capacitor Run — Single Speed
SWITCH
RUN. CAP.
SINGLE SPEED MOTOR — TYPICAL SCHEMATIC DIAGRAMS
Capacitor Start* or Split Phase
Single Voltage on Winding Protector
SWITCH
*Capacitor not shown in schematic.
A.O.Smith
52
Pump Motors
SWITCH CONNECTIONS — HIGH SPEED START
WHITE
(COMMON)
TOP VIEW
START
CAPACITOR
LOW
HI
YELLOW TO #5
(FROM START WINDING)
RED TRACER
YELLOW TO #1 TO #5
RED TO #2
BLACK
BLACK TO #3
TO #4
(4 POLE MAIN)
YELLOW TO #1
(2 POLE MAIN)
TERMINAL #1
TERMINAL #2
TERMINAL #5
TERMINAL #3
TERMINAL #4
END VIEW
A.O.Smith
53
Pump Motors
SWITCH CONNECTIONS — LOW SPEED START
Low speed start — this design motor always starts on the low speed
(4-pole) windings. When the control calls for high speed run, the start switch
automatically switches the motor to high.
WHITE
(COMMON)
TOP VIEW
LOW
▼
HI
▼
YELLOW TO #4
BLACK TO #5
RED TRACER
(FROM START WINDING)
YELLOW TO #3
(2 POLE MAIN)
BLACK #1 TO #5
RED TO
#2
YELLOW TO #4
BLACK TO #1
(4 POLE MAIN)
TERMINAL #2
TERMINAL #1
TERMINAL #5
TERMINAL #3
TERMINAL #4
END VIEW
A.O.Smith
54
Pump Motors
2-SPEED MOTORS — HIGH SPEED START
SCHEMATIC DIAGRAM
2-Speed for Remote Switch Operation
WHITE
LINE VOLTS
(LOW SPEED)
BLACK
Z
BLACK
LINE VOLTS
(HIGH SPEED)
Y
X
START
CAPACITOR
RED
YELLOW
HI
START - X & Y CLOSED Z
OPEN
RUN - X & Y OPEN Z CLOSED
A.O.Smith
55
Pump Motors
2-SPEED MOTORS — HIGH SPEED START SCHEMATIC
DIAGRAMS AND RECONNECTION INSTRUCTIONS FOR
REMOTE OPERATION
2-Speed with Hi - Low Switch
Mounted on Motor Canopy
WHITE
BLACK
LINE VOLTS
RED
START
CAPACITOR
RED
BLACK
HI
PURPLE
LOW
CANOPY SWITCH
YELLOW
YELLOW MUST BE CONNECTED
TO BOTTOM TERMINAL WITH
SWITCH IN POSITION SHOWN
NOTE:
START
RUN
- X & Y CLOSED Z OPEN
- X & Y OPEN
Z CLOSED
Several different connections have been used in production. If the wiring on the motor
you are reconnecting does not match these diagrams contact A.O. Smith and we will
FAX or mail a connection for that model.
RECONNECTION FOR REMOTE SWITCH OPERATION
REMOVE BOTH YELLOW LEADS
FROM ‘A’ TERMINAL AND CONNECT
TO TERMINAL L1.
REMOVE BLACK LEAD FROM HI-LOW
SWITCH AND CONNECT IT TO
TERMINAL A.
LEAVE SWITCH IN CANOPY AND
LEAVE PURPLE LEAD CONNECTED
TO SWITCH.
CONNECT POWER SUPPLY LINES TO
TERMINAL BOARD
L2-L1
HIGH SPEED
L2-A
LOW SPEED
HI-LOW SWITCH
PURPLE
YELLOW
BEFORE REPLACING MOTOR
CANOPY, BE SURE ALL LEADS ARE
PROPERLY PLACED TO PREVENT
DAMAGE FROM GOVERNOR AND/OR
CANOPY.
A.O.Smith
56
Pump Motors
2-SPEED MOTORS — HIGH SPEED START SCHEMATIC
DIAGRAMS AND RECONNECTION INSTRUCTIONS FOR
REMOTE OPERATION
2-Speed with Hi - Low Switch
Mounted in External Box
BLACK
START
CAPACITOR
YELLOW
NOTE:
Several different connections have been used in production. If the wiring on the motor
you are reconnecting does not match these diagrams contact A.O. Smith and we will
FAX or mail a connection for that model.
RECONNECTION FOR REMOTE SWITCH OPERATION
DISCONNECT PURPLE AND YELLOW
LEADS FROM HI-LOW SWITCH AND
CONNECT TOGETHER.
DISCONNECT BLACK TRACER LEAD
FROM HI-LOW SWITCH PERMANENTLY. TAPE UP EXPOSED END.
L2
CONNECT POWER SUPPLY LINES TO
TERMINAL BOARD
L2-L1
HIGH SPEED
L2-A
LOW SPEED
COMMON
B
SWITCH BOX
BLACK TRACER
A
PURPLE
L1
YELLOW
A.O.Smith
531 NORTH FOURTH STREET
TIPP CITY, OH 45371
937) 667-2431
FAX: (937) 667-5873
www.aosmithmotors.com
© 2006 A.O. Smith Corporation
Bulletin #3400
12/06