2002 NEC Code Changes

2002
National Electrical Code
Changes
Developed and Presented by:
The Codes and Standards Group of
Schneider Electric
Where We Started
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Development Timeline
Proposal Deadline
November 5, 1999
Code-Making
Panels Meet
Jan 10-22, 2000
Written Ballots Due
Feb 17 (or 24),
2000
Technical Correlating
Committee Meeting
May 8-12, 2000
NEC Report on
Comments Available
July 14, 2000
Public Comment
Development Timeline
Public Comments
Due to NFPA
October 27, 2000
Code-Making
Panels meet
Dec 4-16, 2000
Written Ballots Due
Jan 5 (or 12), 2001
Technical Correlating
Committee Meeting
Feb 25 - Mar 1
NEC Report on
Comments Available
April 16, 2001
NFPA Annual
Meeting
May 13-17, 2001
Standards Council hears
Appeals on July 11, 2001
2002 NEC Issued with
Effective date of August 2, 2001
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Use of the 2002 NEC
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2002 is the Latest Edition of NFPA 70
Most jurisdictions specify what edition of
the NEC they follow
Adoption process must recognize the 2002
edition in order for it to be the “active”
document in the locality
Some jurisdictions have already completed
process to utilize the 2002 edition on
January 1, 2002
n e.g. North Carolina, Massachusetts
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Other jurisdictions may not adopt the 2002
edition until some future date
Numbering Format
From Dash to Dot
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Acronyms
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2002 NEC will use standard acronyms
Examples
n RMC – Rigid Metal Conduit
n RNMC – Rigid Nonmetallic Conduit
n EMT – Electrical Metallic Tubing
n LFMC – Liquidtight Flexible Metal Conduit
n ENT – Electrical Nonmetallic Tubing
n IMC – Intermediate Metal Conduit
n NUCC – Nonmetallic Underground Conduit with Conductors
n AC – Armored Cable
n NM – Nonmetallic sheathed cable
Article 80 (New)
Administration and Enforcement
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Provides a set of model administrative rules to
apply and enforce the NEC
Covers
n Inspection
n Investigation of electrical fires
n Review of construction plans, drawings and
specifications
n Design, alteration, modification, construction,
maintenance and testing
n Regulation and control of special events
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Article 80 is informative only (not part of the
Code) unless specifically adopted by the
jurisdiction
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90.1(D) - Purpose
Relation to International Standards
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NEC addresses fundamental principles
of protection for safety contained in IEC
60364-1, Section 131
Protection against:
n Electrical shock
n Thermal effects
n Overcurrent
n Fault-currents
n Overvoltage
90.2(B)(5) – Scope
Under exclusive
control of a utility:
Not Covered
Service drops or
laterals and
associated metering
Located in legally established
easements, rights of way, etc and
recognized by regulatory agencies
On property owned or leased by the utility for
purpose of communications, metering, generation,
control, transformation, transmission, or distribution
of electric energy.
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90.3
Code Arrangement
Chapter 1 - General
Chapter 2 - Wiring and Protection
Chapter 3 - Wiring Methods and Materials
Chapter 4 - Equipment for General Use
Supplements or modifies
Chapters 1 through 4
Chapter 9 - Tables
Annex A through Annex D
Chapter 5 - Special Occupancies
{
Chapter 8 - Communications Systems
}
Applies generally to all
electrical installations
Chapter 6 - Special Equipment
Chapter 7 - Special Conditions
Chapter 8 is not subject to the
requirements of Chapters 1
through 7 except as specifically
referenced in Chapter 8
}
} Applicable as referenced
} Information only not mandatory
90.4
Enforcement
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The authority having jurisdiction can
waive specific requirements or permit
alternative methods
Only allowed where “equivalent safety”
is assured
Now requires “special permission”
n Special permission as defined in Article
100 requires written consent of the
authority having jurisdiction
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90.7
Examination of Equipment for Safety
Definition of “Listed” in Article
100 states that products must meet
appropriate designated standards.
90.7 states that examination of
equipment for safety under standard
conditions provide a basis for
approval.
90.7 FPN No. 3 notes that
Annex A contains and
informative product standards
list
Annex A – Product Safety
Standards
• Informative only
• List of standards used for
product listing
What are the “appropriate”
designated standards?
• Makes the connection
between the Code rules and
properly evaluated products
90.9 – Units of Measurement
Compliance
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NEC now has metric as the first dimension listed
The conversions are not exact
n e.g. 1m (3 ft)
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The installation can be made to either the SI (metric) or the
“inch-pound” units
Wire sizes did not change – still AWG and kcmil
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Article 100 – Definitions
Authority Having Jurisdiction
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The organization, office, or, individual
responsible for approving equipment,
materials, an installation, or a procedure.
This term is standardized through out the
NFPA system
Examples include
n Public safety – electrical inspector, fire marshal,
fire chief, building official, others having
statutory authority
n Insurance purposes – insurance inspection
department, rating bureau
n Others – property owner or designee
n Government – commanding officer,
departmental official
Article 100 - Definitions
Ground-Fault Circuit Interrupter
Definition now makes it clear that a
device intended to provide protection of
personnel must be a Class A device.
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Article 100 - Definitions
Luminaire
A complete lighting unit consisting of a lamp or lamps together with
the parts designed to distribute the light, to position and protect the
lamps and ballast (where applicable), and to connect the lamps to the
power supply.
Fixture
Luminaire
Lighting fixture
Article 100 – Definitions
Qualified Person
One who has the skills and knowledge
related to the construction and operation of
the electrical equipment and installations
and has received safety training on the
hazards involved.
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Article 100 – Definitions
Structure
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“That which is built or
constructed”
Not previously defined in
the NEC
Compatible with other
building codes and
standards
110.12(A) – Mechanical Execution of Work
Unused Openings
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Combines the requirements in
Article 110 with the requirements
covering cabinets and cutout
boxes
Applies to boxes, raceways,
auxiliary gutters, cabinets, cutout
boxes, meter socket enclosures,
equipment cases and housings
Must be substantially equivalent to
the wall of the equipment
Metallic plugs in nonmetallic
enclosures must be recessed at
least 6 mm
Box
Close all unused openings
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110.14(C) – Electrical Terminations
Temperature Limitations
Ampacity of the conductor (for ambient
adjustment and derating) is permitted to be based
on appropriate table (e.g. 310.17 for single
conductors in free-air)
Ampacities for conductors at
equipment terminations must be
based on Table 310.16
110.15 (new)
High-leg Marking
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New section added to require the
marking of the high- leg of a 4wire delta connect system with
orange color or other effective
means
Identification required at each
point on the system where a
connection is made if the
grounded conductor is also
present
120V
120V
208V
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110.16 (New)
Flash Protection
Switchboards, panelboards, industrial control panels, and motor control centers
that are likely to be worked on while energized
DANGER Arc -Flash Hazard
Protective Equipment required
in accordance with NFPA 70E
Failure to use proper equipment
can result in serious injury or death
Field Marked with a label to warn of potential electric arc flash hazards
Equipment in dwelling units is not included in the requirement
110.26(C)(2) – Entrance to Working Space
Large Equipment
Where the entrance to
the space has a
personnel door, it must
open in the direction of
egress and be equipped
with panic bars, pressure
plates, etc.
Similar rule for over 600V
equipment in 110.33
Equipment over 1200A and over 6 feet wide
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110.26(F) – Spaces about Electrical Equipment
Dedicated Equipment Space
Piping
Drip
protection
Space above the dedicated
space up to the structural
ceiling is permitted to have
foreign systems, provided
protection from leaks or
breaks is provided
Dedicated space extends 6
feet above the height of
the equipment. Only
electrical equipment
allowed in this space.
Space is the same width
and depth as the
equipment.
110.31
Enclosure for Electrical Installations
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Fence shall not be less than 7ft in height
Table 110.31 Minimum Distance from Fence to Live Parts
Does not apply to enclosed equipment
Minimum Distance to
Live Parts
Nominal Voltage
601 - 13,799
13,800 -230,000
Over 230,000
m
3.05
4.57
5.49
ft
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15
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110.58 – Tunnel Installations over 600V
Disconnecting Means
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A switch or circuit breaker shall be installed within sight of
each transformer or motor location to serve as the disconnect.
200.6
Means of Identifying Grounded Conductors
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The word “natural” has been deleted
from “natural gray”
Gray conductors are now permitted as
grounded conductors
Allows “gray” to be used for an
ungrounded conductor to distinguish one
system from the other
n e.g. white for 120/240V and gray for
480Y/277V
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210.6(E) – Voltage Limitations
Over 600 Volts Between Conductors
Over 600V circuits can supply
utilization equipment in installations
where conditions of maintenance and
supervision ensure that qualified persons
will service the installation.
4160V
Compressor
210.7
Branch Circuit Receptacle Requirements
New Article 406 covering
Receptacles
1999 NEC
210-7 covered:
• Requirements for
grounding type
receptacles
• Methods of grounding
receptacles
Moved to
• Replacement of
receptacles
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210.7(C) – Receptacle Requirements
Multiple Branch Circuits
Supplied by more than one branch
circuit (can be multiple single circuits
or a multi-wire circuit)
More than one
receptacle on a yoke
Ø
Ø
N
Must be provided with a means to
simultaneously disconnect the
ungrounded conductors at the
panelboard where the circuits
originate
210.8(A)(5) Exception No. 3 – Dwelling Units
Unfinished Basements
Omission of GFCI protection
Fire and/or
Burglar Alarm
Control Panel
Remove tab to
limit to one
receptacle
Receptacle supplying
only a permanently
installed fire alarm or
burglar-alarm
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210.8(A)(8) – Dwelling Units
Boathouses
15- and 20-ampere receptacles in boathouses
on dwelling unit property are required to have
GFCI protection.
Article 555 now excludes private,
noncommercial docking facilities for singlefamily dwellings
210.8(B)(3) – Other than Dwelling Units
Kitchens
GFCI protection now required for 15 and 20A receptacles in
kitchens located in other than dwelling unit
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210.12
Arc-Fault Circuit-Interrupter Protection
Requirements:
•
All branch circuits supplying 15 or 20A outlets in
the bedroom
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NOTE: see definition of “outlet” in Article 100,
this includes lighting outlets
•
AFCI must be listed to provide protection of the
entire branch circuit
210.19(B) – Minimum Ampacity and Size
Branch Circuits Over 600 Volts
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Ampacity in accordance with Table
310.15 and 310.60
Size conductors at not less than 125% of
the “designed potential load” of
equipment to be operated
simultaneously
OR
Sized by the engineer for supervised
installations
n Design and installation are under
engineering supervision
n Qualified persons with documented training
and experience in over 600V systems
provide maintenance, monitoring, and
servicing of equipment
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210.23
Permissible Loads
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No change to the code language
Panel Statement is significant:
n The 80% limitation on any single cord- and plug-connected appliance
on a circuit with two or more receptacles applies to both continuous or
intermittent loads
210.52
Dwelling Unit Receptacle Outlets
Modified to indicate this section provides requirements
for 125-volt, 15 and 20 ampere receptacle outlets.
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210.52(C)
Countertops
Receptacle installed in appliance garage
does not count as one of the required
outlets.
Must be not more than 24” to meet
210.52(C)(1)
210.52(C)(5) Exception - Countertops
Receptacle Outlet Location
Where a receptacle is
mounted above the cabinets,
it must be within 20” of the
countertop to be counted as
one of the required
receptacles.
Not more than 20”
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210.52(D)
Bathrooms
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Receptacle now permitted to
be installed on a partition or
a wall
Wall or partition must be
“adjacent” to the basin or
basin countertop
The receptacle must be
within 3 feet of the outside
edge of the basin
Wall
Half-wall or
partition
210.52(G)
Basements
GFCI Protected
Unfinished portion
GFCI Protected
Finished Basement normal receptacle
placement
Unfinished portion
A receptacle must be placed in each unfinished portion of the basement
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210.63
Heating, AC, and Refrigeration Equipment Outlet
Receptacle
required within
25’ of all heating,
AC or
refrigeration
equipment
regardless of the
type of installation
25’ max
210.70(A)(2)(c) – Dwelling Units
Lighting Outlet Switch Locations
Switch required at landing level if there is an
entry at the landing.
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215.2(B) – Minimum Rating and Size
Feeders Over 600 Volts
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Ampacity in accordance with 310.15 and 310.60
Transformers – conductors supplying transformers shall not
be less than the nameplate rating of the transformer
Transformers and utilization equipment - Size conductors at
not less than 125% of the “designed potential load” of
equipment plus the nameplate ratings of the transformers
OR
Sized by the engineer for supervised installations
n Design and installation are under engineering supervision
n Qualified persons with documented training and experience in over
600V systems provide maintenance, monitoring, and servicing of
equipment
225.26
Vegetation as Support
Support of overhead conductor spans by vegetation is not permitted.
The exception for temporary wiring has been deleted.
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230.6
Conductors Considered Outside the Building
Installed under not less
than 2” of concrete
beneath a building or
structure
Installed in conduit and
under not less than 18”
of earth beneath a
building or structure
Encased in not less
than 2” of concrete
or brick
Installed in a vault that meets Article 450 Part III
230.40 Exception No. 1 – Service Entrance Conductors
Number of Service Entrance Conductor Sets
Occupancy #1
Occupancy #2
240V Service
Occupancy #3
480V Service
Permits a set of service entrance conductors run to each occupancy for each
service of different characteristics as defined in 230.2(D)
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230.70(A)(3) - Location
Remote Control
Shunt trip or
“remote control”
The service equipment must still
be located at a readily accessible
location where the conductors
enter the building
230.82
Equipment Connected to the Supply Side of Service Equip
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Additional Equipment
Supply
n Meter sockets
n Meter disconnect switches rated 600
Volts max
n Fuel Cell Systems
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Surge Protective Devices removed
from list of permitted devices
n Surge Arresters are still included in the
Meter
disconnect
switch
480Y/277V
Typical
permitted list of devices
n Removed in order to clarify TVSS
products are not permitted
On to service
equipment
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230.212
Over 35,000 Volts
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Section previously applied when
voltage exceeded 15,000 volts
Where service conductors enter a
building they must terminate in
metal-enclosed switchgear
compartment or a vault complying
with Article 450 Part III
240.2
Definitions
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Coordination
n The proper localization of a fault condition to restrict outages to the
equipment affected, accomplished by the choice of selective faultprotective devices
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Current limiting overcurrent protective device
n Moved from 240.11
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Supervised industrial installation
n Moved from 240.91
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Tap conductors
n Moved from 240.3(D)
n Clarified to exclude service conductors
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240.21(B)(5)(4)c – Feeder Taps
Outside Taps of Unlimited Length
Feeder Tap
Conductors
installed in
accordance with
230.6
Equipment at a readily
accessible location where
the conductors enter
240.21(C)(6) – Transformer Secondary Conductors
Secondary Conductors Not Over 25’ Long
Primary conductors
protected at their
ampacity
Conductors terminate in a single
CB or set of fuses that limit load
current to the ampacity of the
secondary conductors
200A
480V
240V
25’ max
150A conductors
Secondary conductors have an ampacity that is at
least 1/3 the rating of the primary device when
multiplied by the voltage ratio
150A
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240.24(B) Exception No. 2 – Location In Premises
Occupancy
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General rule requires that
each occupant have ready
access to overcurrent
devices that supply that
occupancy
Exception recognizes that
occupants of hotel/motel
rooms do not need access
if the building is under
continuous building
management supervision
240.83(D) - Marking
Used as Switches
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Requires a breaker listed and
marked as HID (high intensity
discharge) to be used as a switch
for HID lighting
Florescent lighting can be
switched with breakers marked
SWD or HID
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240.85 – Circuit Breakers
Applications
Clarifies that “slash” rated
breakers should be applied
only in solidly grounded
circuits
Slash Rated
Breaker OK
Article 240 Part VIII
Supervised Industrial Installations
At least one service more
than 150V to ground and
300V phase-to-phase
Conditions of maintenance and
engineering supervision ensure
that only qualified persons monitor
and service the system
System has at least 2500 kVA of load
used in industrial process and/or
manufacturing (calculated in
accordance with Article 220)
Does not apply to
offices, garages,
warehouses, etc.
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240.92(B)(1)(1) – Transformer Secondary Conductors
Short-Circuit and Ground-Fault Protection
Primary overcurrent device not more than 150% of the
secondary conductor ampacity multiplied by the
secondary to primary voltage ratio
Secondary conductor length
changed from 50 feet to 100 feet
See 240.92(B)(2) for overload
protection requirements
240.92(B)(1)(2) – Transformer Secondary Conductors
Short-Circuit and Ground-Fault Protection
Differential
Relay
Conductor secondary
is now permitted to be
of any length
See 240.92(B)(2) for overload
protection requirements
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240.92(B)(1)(3) – Transformer Secondary Conductors
Short-Circuit and Ground-Fault Protection
Secondary conductors considered protected if calculations made under
engineering supervision determine that the system overcurrent devices will
protect the conductors within the recognized time-current limits for ALL shortcircuit and ground-fault conditions.
Secondary conductor length
limitation removed
240.92(D) – Location in Circuit
Protection by Primary Overcurrent Device
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Secondary conductors are
permitted to be protected by the
primary overcurrent device
Primary device time-current
characteristics multiplied by the
effective primary to secondary
voltage ratio must effectively
protect the secondary conductors
Difficult to use with transformers
that have greater than a 1:1 ratio
of primary L-L voltage to
secondary L-L voltage
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250.4(B) – General Requirements for Grounding
Ungrounded Systems
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Material moved from 250.2
where it was mixed with
grounding system
requirements
Ground all non-current
carrying conductive
materials of electrical
equipment
Bond together all noncurrent carrying conductive
materials together to create a
permanent, low- impedance
path for ground-fault current
1st fault
grounds the
system
250.20
AC Circuits and Systems to Be Grounded
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Specifies what systems are
required to be grounded
Notes that other systems are
permitted to be grounded
Now clarifies that if a system is
grounded (either required or
permitted) the grounding must
comply with Article 250
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250.30(A)(2)(b) and (3) – Sep Derived Systems
Grounding Electrode Conductor
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Allows a common grounding
electrode for multiple
separately derived systems
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Must use exothermic weld,
irreversible compression or
connect to copper bus bars
Keep main grounding
electrode conductor without a
splice or joint
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Separately Derived Systems
Size common grounding electrode
conductor based on 250.66 using
the total area of largest derived
phase conductor from each system
Size “tap” conductors based on
250.66 based on the derived
phase conductor size
Grounding Electrode
(example shown is
water pipe)
250.32(E) – Two or More Buildings/Structures
Grounding Electrode Conductor
Service Equip - Bldg #1
Bldg #2
Grounding electrode
conductor sized by
250.66 based on largest
ungrounded supply
conductor.
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Article 250
Part III – Grounding Electrode system
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250.52 establishes the electrodes
PERMITTED for grounding
n Metal underground water pipe
n Metal frame of the building or structure
n Concrete encased electrode
n Ground ring
n Rod and Pipe electrodes
n Plate electrodes
n Other local metal undergrounds systems
or structures
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250.52(B) establishes electrodes
NOT permitted for grounding
n Metal underground gas piping
n Aluminum electrodes
Gas Pipe
250.53(C) – Grounding Electrode System Installation
Bonding Jumper
• Install – 260.64(A), (B) and (E)
• Size - 250.66
• Connect – 250.70
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250.102(E) – Equipment Bonding Jumper
Installation
Equipment bonding jumper permitted longer than 6’
permitted to bond isolated sections of metal raceways
Rigid metal conduit
Rigid nonmetallic conduit
250.104(A) – Bonding of Piping Systems
Metal Water Piping
Requires bonding of water
pipe that is “installed in”
or “attached to” a building
or structure.
“Attached to”
“Installed in”
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250.104(B)
Bonding of Other Metal Piping
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Deleted old 250-104(c) that required
bonding of all metal gas piping to the
grounding electrode
Gas piping now covered under
240.104(B) which requires bonding of
piping that is “likely to become
energized”.
Bonding jumper sized based on the
overcurrent device protecting the circuit
that is likely to energize the piping.
The equipment grounding conductor of
the circuit is permitted to serve as the
bonding means
Gas Piping
Branch Circuit
250.122(B) – Equipment Grounding Conductors
Increase in Size
Now requires proportional increase in equipment grounding
conductor when phase conductors are increased for any reason.
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250.146(A)
Surface Mounted Box
Box must be mounted “on” the surface
Previous code allowed a box
mounted “at” the surface to
use metal to metal contact.
Now a yoke must be listed
to establish the grounding
path for other than surface
mounted boxes.
Direct metal to metal
contact acceptable for
grounding the receptacle
Article 285
Transient Voltage Surge Suppressors (TVSS)
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Service. The TVSS shall be connected on the load side of a
service disconnect overcurrent device
Separately Derived System. The TVSS shall be connected
on the load side of the first overcurrent device in a separately
derived system.
Short Circuit Current Rating. The TVSS shall not be
installed at a point on the system where the available fault
current exceeds the marking on the equipment.
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285.1 - TVSS
Article Scope
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Covers
n general requirements
n installation requirements
n connection requirements
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Permanently installed only
285.3 - TVSS
Uses Not Permitted
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Circuits exceeding 600 volts.
Ungrounded electrical systems as
permitted in Section 250.21.
Where the rating of the TVSS is less
than the maximum continuous phaseto-ground power frequency voltage
available at the point of application.
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285.5 - TVSS
Listing
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The TVSS shall be Listed.
Most TVSS products will reference:
n UL 1449 2nd Edition on the product.
285.6 - TVSS
Short Circuit Current Rating
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The TVSS shall be marked with a short circuit current rating...
n DO NOT confuse the Short Circuit Current Rating (SCCR) with the
Surge Current (Capacity) Rating !!!
The Surge Current Rating is the maximum transient current level that can
be suppressed by the TVSS.
u The Short Circuit Current Rating is the available and sustainable power
current level that can flow in the circuit, at the point of connection to the
system, during a fault condition until the circuit is opened.
u
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Chapter 3 Reorganization
Articles Moving to Different Chapters
Moving to
305
527
380
404
384
408
Chapter 3 Reorganization
Wiring Method Article Renumbering
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See new Annex F for cross-reference
Articles 312-314 covers boxes and enclosures
n Outlet boxes, cabinets, etc.
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Articles 320-340 covers cables
n MI, MC, AC, NM, UF, etc.
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Articles 342-356 covers conduits
n RMC, RNMC, FMC, etc.
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Articles 358-362 covers tubing
n EMT, ENT, FMT, etc.
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Articles 366-390 covers other methods
n Busway, cable bus, etc.
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Articles 392-398 covers open wiring
n Knob and tube, open wiring on insulators, etc.
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Chapter 3 Reorganization
Common Number Method for all articles
.1 Scope
.2 Definitions
.6 Listing Requirements
Part B Installation
.10 Uses Permitted
.12 Uses Not Permitted
.16 Temperature Limits
.30 Securing and Supporting
.60 Grounding
Part C - Construction Specifications
.110 Corrosion Protection
.120 Markings
300.1(C)
Metric Designators and Trade Sizes
Neither the metric designator
nor the trade size relate to
actual dimensions of the
conduit or tubing.
Metric Designator
12
16
21
27
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Trade Size
3/8
½
¾
1
1¼
41
53
63
78
91
103
129
155
1½
2
2½
3
3½
4
5
6
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300.4(B)(1) – Protection Against Physical Damage
NM Cable and EMT Through Metal Framing Members
Metal Stud
A listed bushing or grommet
must cover all metal edges and
be securely fastened to the
opening
300.5(D)(3) – Underground Installations
Service Conductors
18” or more
18” or more
At least 12”
Warning
Ribbon
Applies to all underground service conductors
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300.5(K) – Protection Against Physical Damage
Directional Boring
Cables and raceways installed using
directional boring equipment shall
be “approved” for the purpose.
300.6(A) – Protection Against Corrosion
General
Where threads are cut in the field, the
threads shall be coated with an approved,
electrically conductive, corrosion resistant
compound.
Located in an area where corrosion protection is necessary
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300.7(A) – Raceways Exposed to Different Temperatures
Sealing
Raceway
Interior - 72°F
Exterior - 25°F
Fill raceway with approved material
to prevent circulation of warm air to
cold air region
300.11(C) – Securing and Supporting
Cables Not Used as Means of Support
Cable wiring method (e.g. MC cable)
Other cable or raceway (e.g. Class 2 circuit)
Cable wiring methods are not permitted to support other cables or raceways
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300.22(B) – Wiring in Ducts, Plenums or Other Spaces
Ducts or Plenums Used for Environmental Air
Change specifically prohibits
conduit with an overall
nonmetallic coating
Ducts or plenums in
300.22(B) are those
specifically fabricated to
transport environmental
air.
300.22(C) – Other Spaces Used for Env Air
Wiring Methods
Return Air Space
Suspended ceiling
Rigid metal conduit with a nonmetallic coating now prohibited
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310.15(B)(2) – Exception No. 5
Adjustment Factors – AC or MC Cable
MC or AC cable
No adjustment factor required
where not more than 20 current
carrying conductors are in the
stack or bundle.
• #12 AWG conductors
• Not more than 3 current
carrying conductors per cable
• No overall outer jacket
For more than 20 current carrying
conductors, a 60% adjustment factor applies
Table 312.6(B)
Minimum Wire Bending Space at Terminals
The table now recognizes smaller wire bending space for compact stranded
AA-8000 aluminum conductors
Using an example of a 400A circuit:
1999 NEC
2002 NEC
Cu – 3/0 - 6 ½ inches
Cu – 3/0 - 6 ½ inches
Al – 250 kcmil – 8 ½ inches
Al – 250 kcmil – 6 ½ inches
46
314.20
In Wall or Ceiling
Surface of concrete, tile, gypsum, plaster or
other noncombustible material
Box not set back more than ¼”
from the finished surface
For surfaces of wood or other combustible
material, the box must be flush with the
finished surface
314.23(B)(1) – Structural Mounting
Nails and Screws
Where nails or screws are used to fasten a box, the
nail or screw must pass thru a bracket outside of
enclosure or must pass through the inside with ¼” of
the back of the enclosure.
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314.27(A) Exception
Boxes at Luminaire Outlets
Use #6 screws minimum
Permits mounting of luminaire to a “standard” outlet box where the
luminaire does not weigh more than 6 lb. Dimensional limitation on
the fixture has been removed.
314.27(B) – Outlet Boxes
Maximum Luminaire Weight
Outlet box identified
for luminaire (fixture)
support
Luminaire weighing not more
than 50 lbs.
Luminarie’s weighing over 50 lbs must be supported independently of
the outlet box
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330.10(13) – Uses Permitted
Single-Conductor MC
Installation of single-conductor MC
must comply with NEC 300.20.
Single-conductor MC is
required to have a nonmagnetic
sheath or armor (NEC 330.116)
Where single conductor MC is
used, the phase and neutral (if
used) conductors shall be
grouped together to minimize
induced voltage
332.80 – Ampacity
Single Type MI Conductors Grouped Together
Not less than 2.15 times
diameter of largest conductor
in the group
Open runs or on a messenger in a triangle or square configuration
Permitted to use Table 310.17 ampacities for the MI cable.
Temperature limitation of equipment terminations must be considered.
Ampacity will be required to be reduced back to Table 310.16 levels before
terminated within equipment.
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334.6 – NM Cable
Listed
NM Cable is required to be listed
334.10(2) – NM Cable
Uses Permitted
Multifamily dwellings and other buildings
that are of Type III, IV or V construction.
New Appendix E will contain a table from
NFPA 220 to explain the different
building Types
The building code in effect locally will
also define the building types
In general, this permits NM to be used in
4-story apartment buildings (typically R-2
buildings, Type III and IV)
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Annex E
Types of Construction
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Type III – typically
constructed of
noncombustible,
limited-combustible, or
other approved
combustible material
Type IV – typically
timber frame
construction
Type V – typical stick
built construction
Explanation of Headers – Example = 211 Construction
2 = 2 hr fire rating of exterior load bearing walls
1 = 1 hr fire rating of columns, beams, girders that support bearing walls
or loads from more than one floor
1 = 1 hr fire rating of floor
334.12(A)(1) – Uses Not Permitted
Types NM, NMC and NMS
Space above suspended ceiling in
other than one, two and multi-family
locations
NM cable not permitted in this
space
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338.10(B)(4) – Uses Permitted
Installation Methods for Branch Circuits and Feeders
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Applies installed as a
branch circuit or feeder
Must be installed in
accordance with Article
334 (NM Cable) Parts I
and II
Specifically excludes
334.80 requirement that
limits ampacity of NM
cable to 60C
342.22
Number of Conductors
IMC
Conductor fill must comply with Table 1, Chapter 9
Cables are permitted to be installed where such use is permitted
by the respective cable articles.
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344.24
Bends – How Made
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One shot and Full shoe
benders contained in one
table
Minimum radius is now
measured to the centerline
of the conduit
362.10(2) Exception – Installation
Uses Permitted
ENT
15 minute finish rating not
required
NFPA 13 sprinkler system throughout
the building
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400.8(5)
Uses Not Permitted
Flexible cord not permitted above a
suspended or drop ceiling
404.6(C)
Connection of Switches
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General rules says that blades must
be de-energized when in the open
position
New text recognizes that a bottom
fed bolted pressure switch can have
energized blades if barriers are
provided
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404.8(B) – Accessibility and Grouping
Voltage Between Adjacent Devices
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Applies to switches grouped in an
enclosure with other switches, receptacles
or similar devices
Voltage between adjacent devices must
not exceed 300V
A permanently installed barrier can be
used to separate devices where the
voltage does exceed 300V
404-14(E)
Dimmer Switches
Dimmer switches are permitted to supply only
permanently installed incandescent luminaries,
unless listed for the control of other loads.
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404.15(B) – Marking
Off Indication
If a switch has a marked off
position, it shall disconnect all
ungrounded conductors
Off
On
Auto
406.4(E)
Receptacles in Countertops and Similar Work
Surfaces in Dwelling Units
Receptacles not permitted to be mounted face-up in any
countertop or work surface in a dwelling unit
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406.8(B)(1)
15- and 20-Ampere Outdoor Receptacles
Requires the use of a “weatherproof”
while in use cover in all outdoor wet
locations.
Applies to 15 and 20 ampere, 125 and 250-volt receptacles
406.8(B)(2)
Other Receptacles
Requires the use of a “weatherproof”
while in use cover in all outdoor wet
locations where the product intended to be
plugged in is not attended while in use
(e.g. sprinkler controllers, landscape
lighting, holiday lighting, etc.
For applications where the plugged in
equipment will be attended while in use
(e.g portable tools), a basic weatherproof
cover can be used.
Applies to receptacles other than 15 and 20 ampere, 125 and 250-volt
57
408.4
Circuit Directory
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All circuits or circuit
modifications shall be
legibly identified as to their
purpose
Located on the panel face
or inside the panel door
Located at each switch on a
switchboard
Now applies to both switchboards
and panelboards!
408.21
Grounded Conductor Terminations
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Each grounded conductor
must terminate in an
individual terminal
n Do not put two “neutrals” in
one terminal
n Do not put a neutral and an
equipment ground in one
terminal
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Multiple equipment
grounding conductors can
still be terminated in a
terminal if the panel is
identified to allow the
multiple connection
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410.18(B) Exception – Exposed Luminaire Parts
Made of Insulating Material
Separate equipment
grounding conductor
installed in accordance
with 250.130(C)
Grounding means not
available at the outlet
Replacement luminaire.
Permitted to have conductive
parts.
Grounding Electrode
430.32(C) – Continuous Duty Motors
Selection of Overload Relays
Sep Overload
Device
115% to 125%
Thermal
Protector
140% to 170%
One HP or less,
automatically
started
115% to 125%
Approved for
use with the
motor
430-32(A) and
(B)
130% to 140%
NA
NEC
430-32(A)
Covers
More than 1HP
430-32(B)
430-32(C)
Clarifies that the sensing element or the setting of the overload
relay can be increased if the values in 430.32(A) and (B) are
not sufficient to start the motor.
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430.52(C)(1) – Rating or Setting
In Accordance with Table 430.52
Table moved from 430-152 to become
Table 430.52
430.53(D) – Several Motors or Loads
Single Motor Taps
Group Installation:
multiple motors installed on
one branch circuit
Not more than 10’ in length
Branch shortcircuit/ground-fault
device
Conductors not less
than 1/10 the rating
of the branch SC/GF
device
Listed manual motor
controllers additionally
marked “suitable for tap
conductor protection in
group installations”
Conductors sized by
430.22
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430.62(A) Exception No. 2 – Rating or Setting
Specific Load
Feeder device must have a
rating or setting that does
not exceed the rating of the
MCC main power bus (see
430.92)
Feeder overcurrent device
supplying a Motor-Control
Center
430.102(B) – Disconnect Location
Motor
430.102(B) requires a
disconnect in sight of the
motor
430.102(B) Exception allows
omission of the disconnect in
sight of the motor if one of
the following applies:
(a) the location is
impracticable or
introduces additional
hazards
430.102(A) requires the
disconnect in sight of the
controller
(b) Industrial installation
with maintenance and
supervision and written
safety procedures
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430.102(B) Exception
Motor Disconnect
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Where the exception is used to
eliminate the disconnect at the
motor the controller disconnect
must be
n Capable of being locked in the open
position
n Each disconnect must be
individually lockable
n The locking means must be
permanently installed on or at the
switch or circuit breaker
440.65 – Room Air Conditioners
LCDI or AFCI Protection
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Single-phase cord- and
plug-connected room air
conditioners
Must be provided with
factory- installed
n LCDI (Leakage Current
Detection and Interruption)
n or AFCI (Arc-Fault Circuit
Interrupter)
LCDI
Must be integral with the attachment cap
or located within 12” of the attachment
cap
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500.7(K) – Protection Techniques
Combustible Gas Detection System
Detection system restrictions:
l In industrial establishments with restricted
public access and
l Where conditions of maintenance and
supervision ensure only qualified persons
service installation
l System is listed for detection of specific gas
or vapor
Permitted equipment with detection system:
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Inadequate Ventilation establishes Class I, Div. 1 location
– Electrical equipment suitable for Class I, Div. 2
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Interior of Building with opening into Class I, Div. 2
– Electrical equipment for unclassified locations
Interior of Control Panel – Instrumentation measuring gas
– Electrical equipment suitable for Class I, Div. 2
500.8(A)(1) – Suitable for Class and Properties
Identified
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Suitability of Identification by
n Equipment listing or labeling
n Evidence of equipment
evaluation from a qualified
testing lab or inspection agency
n Evidence acceptable to the AHJ
such as a manufacturer’s selfevaluation or owner’s
engineering judgment
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501.4(B)(3) – Class I Division 2
Nonincendive Field Wiring
Unclassified Location
Classified Location
Nonincendive field wiring –
not capable of igniting
(through arcing or thermal
effects) flammable gas or
vapor under normal operating
conditions.
Cable or wiring method permitted
for unclassified location
Nonincendive field
wiring apparatus
• Install in accordance with the control drawings
• Install in separate cables, cables where each conductor has a grounded
metal shield or in multi-conductor cables where each conductor has a min
of .25mm of insulation
504.80(B) – Intrinsically Safe Systems
Identification of Wiring
Intrinsic Safety
Wiring
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Labels located at least every 25 feet
Visible after installation
Must appear in every section separated by walls, partitions,
etc.
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511.1 – Commercial Garages
Scope
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Includes locations used for
service and repair operations
Self-propelled vehicles
Flammable liquids or
flammable gases used for
propulsion
511.3(B)(2) – Classified Locations
Within 18” of the Ceiling
18”
Class I Division 2 unless provided with four
air changes per hour
CNG Vehicle
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Articles 513 and 515
Zone Classification
Article 513
Aircraft Hangers
Zone 0
Div 1 Zone 1
Div 2 Zone 2
Article 515
Bulk Storage Plants
Zone
classification
system now
permitted
514.1 – Motor Fuel Dispensing Facilities
Scope
Scope and title changed from “Gasoline Dispensing” to “Motor Fuel Dispensing”
Now includes: gasoline, LNG, CNG, etc.
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517.2 – Definitions
Health Care Facilities
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Definition correlates with NFPA 99
Buildings or portions of buildings that include:
n
n
n
n
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Medical
Dental
Psychiatric
Nursing
Obstetrical
Surgical
Includes (but not limited to):
n
n
n
n
n
n
Hospitals
Nursing homes
Limited care facilities
Clinics
Medical and dental offices
Ambulatory care
517.18 – Tamper Resistant Receptacles
Pediatric Locations
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Applies to ALL receptacles in
patient care areas of pediatric wards,
rooms or areas
Listed tamper resistant receptacle, or
Listed tamper resistant cover
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517.30(E) – Essential Electrical Systems
Receptacle Identification in Hospitals
Identification required for receptacles
supplied from the emergency system.
Identification shall be of the cover plate
or the receptacle itself.
Distinctive color or marking so as to be
readily identifiable
Similar requirement exists for emergency receptacles in nursing
homes and limited care facilities [see 517.41(E)]
517.32(G) – Life Safety Branch
Automatic Doors
Connect to the
life safety branch
EXIT
EXIT
Automatically
operated doors used
for building egress
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517.34 Exception
Equipment System Connection to Alternate Power Source
Requirement for time-lag
interval for the equipment
system is not required for
essential systems of less
than 150kVA
Omission of the time-lag
interval allows a single
transfer switch to be used
520.1 – Theaters
Scope
Scope now includes performance
areas and applies to both indoor
and outdoor locations
69
Article 527
Temporary Installations
Temporary Wiring has been renamed
Temporary Installations
The article covers more than just
wiring methods allowed. GFCI’s,
receptacle grounding, disconnecting
means, etc. are also covered.
527.3(B) – Time Constraints
90 Days
The new wording now reflects that the 90 day time limit applies to all
holiday wiring, not just Christmas.
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527.6(A) – Ground-Fault Protection for Personnel
Receptacle Outlets
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GFCI Protection Required for all 125- volt, 15, 20 and 30
ampere receptacle outlets
n Used by personnel during construction, remodeling, maintenance,
repair or demolition
n GFCI in cords sets is acceptable
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Exception for Industrial establishments where
n Qualified personnel are involved
n Assured Equipment Grounding Conductor Program is applied
n Only permitted for receptacle outlets where having GFCI protection
would be a greater hazard or equipment is not compatible with GFCI
protection
527.6(B) – Ground-Fault Protection for Personnel
Use of Other Outlets
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Applies to all receptacles other than 15, 20 and 30-ampere
125-volt
Requires either
n GFCI, or
n Assured Equipment Grounding Conductor Program [527.6(B)(2)]
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547.5(G) – Wiring Methods
Receptacles
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Requires GFCI protection on all
125-volt, 15 and 20-ampere
general purpose receptacles
installed in
n Areas having an equipotential plane
n Outdoors
n Damp or wet locations
547.9 – Power Distribution
Electrical Supply to Buildings/Structures from Distribution Point
Site isolating device (may
be a pole-top disconnect)
Disconnects permitted to be
located at distribution point
– treat like a feeder (250.32
and Article 225)
Alternatively,
disconnects may be
located at the buildings
instead of the
distribution point –
547.9(B)(1)
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547.10
Equipotential Plans and Bonding of Equipotential Planes
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Required where the
following exist
n Concrete floor of
confinement area
n Animals have access to
metal equipment
n The metal equipment is
likely to become
energized
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Must be bonded to the
electrical grounding
system
550.25(B) – AFCI Protection
Bedrooms of Mobile Homes and Manufactured Homes
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Requires AFCI protection on branch circuits that
supply 15 and 20 ampere, 125 volt outlets in
bedrooms
Parallel with 210.12 requirement
HUD rules govern the construction of
manufactured homes. HUD does not yet include
the AFCI requirement.
73
Article 555
Marinas and Boatyards
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Revised to be more consistent with NFPA 303 –
Fire Protection for Marinas and Boatyards
Specifically excludes private, noncommercial
docking facilities associated with single-family
dwellings
Relates electrical requirements to the “electrical
datum plane”
n 2 ft above highest tide level for area under normal
circumstances
n 2 ft above highest water level under normal
circumstances
n 30” above water level at floating pier or landing stage
and a minimum of 12” above the level of the deck
555.19 – Receptacles
Shore Power and Other than Shore Power
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Receptacles for shore power must be
n Not less than 30 amps
n single outlet type
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Receptacles that are 30 to 50 amps must be
of the locking and grounding type
Receptacles 60 to 100 amperes must be of
the pin and sleeve type
GFCI protection required for receptacles
other than shore power located
n Outdoors
n In boathouses
n Buildings used for storage, maintenance or repair
where electrical hand tools or diagnostic
equipment are to be used.
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600.21(F) – Ballasts, Transformers and…
Suspended Ceilings
Flexible
cord not
permitted
Securely supported in place
and not dependent on
suspended ceiling grid for
support
Power supply
for electric sign
Support wires
604.6(E) – Construction
Support
New requirement clarifying that manufactured wiring systems
shall be supported in accordance with the applicable cable or
conduit article.
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645.5(D)(5)(c) – Under Raised Floors
ITC Cable
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Type ITC Cable is now permitted under raised floors to
supply IT equipment.
Equipment grounding conductor may be either green
insulation or green insulation with one or more yellow stripes
Driven by more use of computer systems in instrumentation
and control of industrial locations
645.5(D)(6) – Under Raised Floors
Abandoned Cables
Abandoned cables beneath a raise floor assembly shall be
removed unless contained within a metal raceway.
76
Article 647
Sensitive Electronic Equipment
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New Article
Material from Part G of Article 530
Covers the installation and wiring of
separately derived systems operating at
120V line-to-line and 60V to ground for
sensitive electronic equipment
Expands the permitted use of this system
outside television and motion picture
venues.
60V 60V
120V
Article 680
Swimming Pools, Fountains, and Similar Installations
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Article completely revised
Part I – General
Part II – Permanently Installed
Pools
Part III – Storable Pools
Part IV – Spas and Hot Tubs
Part V – Fountains
Part VI – Pools and Tubs for
Therapeutic Use
77
680.6
Grounding
“Pool” changed to “specified body of water”
n
Grounding requirements for all bodies of water covered
under the scope of 680 now grouped in 680.6
680.12
Maintenance Disconnecting Means
Maintenance disconnect within
sight of the electrical equipment
(not the pool or spa itself)
5ft minimum distance from pool moved to 680.22(C)
78
680.23(F)(1) Exception – Branch-Circuit Wiring
Wiring Methods
LFNC-B permitted to be used in lengths
longer than 6ft where connecting a
transformer to pool lights.
X-fmr
680.26(B)(1) – Bonded Parts
Metallic Structural Components
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Basic rule requires bonding
of steel structure of a pool
(i.e. rebar)
If rebar is insulated by
encapsulation it is not be
required to be bonded
Provisions shall be made for
an alternate means to
eliminate voltage gradients
n
Example: installation of a #8
AWG bare copper conductor
throughout the structure
79
680.26(B)(4) – Bonded Parts
Electrical Equipment
Double-insulated motor
No. 8 copper
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Basic rule requires bonding of all equipment associated with
the circulating system
Double insulated pumps are permitted
Where a double insulated pump is installed, a #8 AWG
bonding conductor is required at the pump location for use
with a replacement motor.
680.27(B)(1) – Electrically Operated Pool Covers
Motors and Controllers
Controls for an electrically operated pool cover shall be located so that
the operator has full view of the pool
80
680.44(B) – Spas/Hot Tubs – Protection
Other Units
GFCI protection required for outlets
that supply a:
• self-contained spa or hot tub
• packaged spa or hot tub
• field assembled spa or hot tub
with a heater load of 50A or
less
Listed assemblies with integral
GFCI protection for all electrical
parts do not require additional GFCI
at the outlet.
A spa or hot tub rated greater than
250V or 3-phase shall not require
GFCI protection.
680.57(C)(2) – Location
Portable Signs
5 ft
Portable electric signs shall not be placed within the pool or
fountain, or within 5 ft (1.52 m ) measured horizontally from
the inside walls of the pool or fountain
81
Article 692
Fuel Cells
Includes requirements for:
• Listing of the fuel cell
• Identification of multiple power sources
• Circuit requirements
• Etc.
700.12(B)(6) – Generator Sets
Outdoor Generator Sets
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Allows disconnect at a generator to also serve
as the disconnect for a building or structure
Comply with the following:
n Generator disconnect must be readily accessible
n Must be “within sight” of the building (visible and
not more than 50 feet away)
n Must still meet the requirements for a building
disconnect in Article 225 (e.g. 225.36 requires that
disconnect be suitable for use as service equipment)
Similar language in 701.11(B)(5)
for legally required systems
82
702.1 – Optional Standby Systems
Scope
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... The systems covered by this article consist of those that are
permanently installed in their entirety, including prime
movers, and those that are arranged for a connection to a
premises wiring system from a portable alternate power
supply.
702.6
Transfer Equipment
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Transfer equipment required for
n permanently installed standby systems
n and where an electric-utility supply is
either the normal or standby source
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Must prevent the inadvertent
interconnection of supplies
Supplementary overcurrent protective
devices shall be part of a listed
transfer equipment.
n Not a substitute for branch circuit or
feeder overcurrent protection
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Comply with Article 705 if system
will be operated in parallel
83
725.3(A) – Locations and Other Articles
Number and Size of Conductors in Raceway
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References 300.17 for all of
Article 725
This extends the raceway wire fill
restrictions to Class 2 and 3
circuits
Applies Chapter 9, Table 1
through references
725.6
Mechanical Execution of Work
Class 1, 2 or
3 circuits
Support wires
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Installed in a neat and workmanlike manner
Support to structural components
Use proper straps, hangers or similar fittings
84
725.52(A) Exception No. 2 – Load Side of Class 2 or 3
Class 1 Wiring Methods and Materials
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Can reclassify Class 2 and Class
3 circuits as Class 1 circuits
Must install as Class 1
Class 2 and Class 3 markings
required in Section 725-42 are
eliminated
Entire circuit is installed using
the wiring methods and materials
in accordance the requirements
for Class 1 circuits
800.48 – Communications Wiring within Buildings
Communications Raceways
New Exception 2: Conduit fill restrictions shall not apply.
85
Annexes
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Annex A – Product Standards
Annex B – Application of 310.10(A) formula
Annex C – Conduit and Tubing Fill Tables
Annex D – Examples
Annex E – NFPA 220 Table for Building
Types
Annex F – Chapter 3 Cross Reference from
1999 to 2002 NEC
The Annex material is for information only
and is not part of the Code requirements
Square D Company
Codes and Standards
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The Codes and Standards group can offer on-site custom
training on the NEC and related topics
Our staff has extensive involvement in codes and standards
development, interpretation and application
Excellent resource for resolution of field issues
86