Assured Grounding

SCALES NW, Inc. GROUNDING ASSURANCE PROGRAM
Policy
Scales NW, Inc has developed and adopted this assured grounding program to provide protection for
employees against electrocution hazards.
Scope
This program will apply to all extension cords or plug and cord sets. It also will apply to three-pronged
tools and all electrical receptacles of 110 volt 15- and 20-ampere ratings.
Equipment Specifications
In order to assure proper grounding and protection of equipment Scales NW, Inc. requires power tools,
extension cords, and receptacles to conform to the following criteria
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Extension cords must be 3 conductor and contain a continuous ground throughout the cord.
Conductors must be a minimum of 14 AWG, for construction and test trucks, and rated at 20
amp or greater.
o Shop cords can be 16 AWG and cords used specifically for instrumentation testing.
A Ground Fault Circuit Interrupter (GFCI) must be used for all corded equipment
o The GFCI will be connected as close to the receptacle as possible
Power tools must have a 3 conductor cord or be double insulated
o Double insulated tools are authorized for use
 Replace defective tools with 3 conductor, grounded, tools
Receptacles must be able to receive a 3 conductor cord without adaptors or modifications
Procedure
All extension cords used on projects must be three-pronged and carry one of the designations required
by the Occupational Safety and Health Administration (OSHA) and the National Electric Code (NEC). Each
extension cord, power tool and receptacle, as defined earlier, shall be tested for grounding continuity.
Any cord, receptacle or tool that has not passed the continuity test shall be tagged and may not be used
until it is repaired and retested.
This program will be implemented and monitored by the operations manager, serving as the competent
person. A “competent person” is one who can identify existing and potential hazards in a job site’s
surroundings or working conditions that are hazardous or dangerous to employees and has the
authority to take prompt corrective measures.
Testing Procedure
Testing of cords will require two pieces of test equipment; a ground fault circuit tester and a digital
multi-meter capable of measuring continuity.
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SCALES NW, Inc. GROUNDING ASSURANCE PROGRAM
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Extension cords must be tested for continuity of all three conductors using a continuity
tester
Power tool ground prong must be tested for continuity to case of tool using a continuity
tester
Receptacles will be tested using a ground fault circuit tester
Testing Frequency
Every corded power tool, shop and vehicle receptacle, and extension cord shall be tested:
 Before the equipment is first used
 Before it is returned to service following any repairs
 Before the equipment is used after any incident that can reasonably be suspected to
have caused damage to the tool, such as a vehicle running over the cord
 At intervals not to exceed one month for tools and extension cords and six months for
receptacles
Color-coding
Scales NW, Inc. has chosen to rely on the OSHA recommended cord marking system of colored tape to
indicate that a piece of equipment has passed the continuity test. Colored tape will be placed on each
piece of equipment according to the chart below. Testing will be conducted on the first working day of
the month for all power tools and extension cords. Receptacles will be tested twice yearly. The
following chart will be used for reference when marking the cords as tested and passed.
Extension cords that do not pass the continuity test will immediately have both cord ends cut off and
the cord marked with brown-colored tape.
Power tools that do not pass the continuity test for the ground conductor will be marked with browncolored tape and placed out of service until the tool is repaired by an capable repair center.
Receptacles that do not pass the ground fault circuit test will be locked out using a receptacle lock out
device and immediately reported to the safety manager.
Scales NW, Inc
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SCALES NW, Inc. GROUNDING ASSURANCE PROGRAM
Record Keeping
Employees are required to document the testing of cords and receptacles on the monthly equipment
inspection forms.
 Inspection documentation will be kept in the vehicle or area where the equipment is stored
 Documentation will remain on file in the area where the equipment is stored until the
equipment is re-inspected the following month
 A copy of the inspection will be kept on file in the operation manager’s office
The grounding assurance program will be reviewed by the operations manager annually to determine if
the current procedures are effective at reducing incidents of injury by electrocution.
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