11 Feb Electrical Cords – Proper Repair and Inspection

Electrical Cords – Proper Repair and Inspection

Electrical cords that are damaged can expose workers to electric shock, burns, electrocution, and fire hazards. Damaged extension cords and flexible cords must be removed from service immediately and may only be repaired when the repair is permitted and restores the cord to a condition suitable for safe use.

Inspect Cords Before Use

Inspect extension cords, flexible cords, plugs, and connectors before use. Look for:

• Cuts, cracks, abrasions, or deterioration in the outer jacket.
• Exposed conductors or insulation.
• Damaged or missing grounding prongs.
• Loose, cracked, or damaged plugs and connectors.
• Evidence of overheating, burning, or melting.
• Loose strain-relief devices.
• Improper splices or makeshift repairs.
• Crushed, pinched, or severely kinked sections.

Do not use electrical tape as a substitute for repairing damaged insulation or restoring the original integrity of a cord.

If a cord is damaged, unplug it, remove it from service, and clearly identify it so another employee does not accidentally use it.

Can a Damaged Cord Be Repaired?

Not every damaged cord should be repaired. Depending on the type and extent of damage, replacement may be the safest and most practical option.

Repairs must not compromise the cord’s:

• Electrical insulation.
• Mechanical strength and flexibility.
• Grounding continuity.
• Strain relief.
• Outer jacket.
• Intended rating and use.

Repairs should only be performed by an employee who is qualified and authorized to perform the electrical work involved.

Do Not Make Makeshift Splices

Extension cords used on construction sites are generally required to be the hard- or extra-hard-service type. Where a flexible cord is permitted to be spliced, the completed splice must retain the insulation, outer sheath properties, and usage characteristics of the original cord.

Do not repair a damaged cord by simply:

• Twisting conductors together.
• Wrapping exposed conductors with electrical tape.
• Covering damaged insulation with duct tape.
• Making an unapproved field splice.
• Leaving conductors or connections exposed.

If an acceptable repair cannot restore the cord to its required condition, replace the cord.

Replacing Plugs and Connectors

A damaged attachment plug or cord connector may sometimes be replaced with an appropriately rated replacement device.

When replacing a plug or connector:

• Disconnect the cord from all electrical power.
• Use a replacement designed for the cord type, conductor size, voltage, amperage, and environment.
• Follow the replacement-device manufacturer’s instructions.
• Maintain correct conductor identification and polarity.
• Connect the equipment-grounding conductor properly.
• Make sure terminal connections are secure.
• Ensure no bare conductor is exposed outside the terminal.
• Secure the cord’s outer jacket within the strain-relief device.

The strain relief should grip the cord jacket—not the individual insulated conductors—and should prevent pulling or twisting forces from being transmitted to the electrical terminals.

Grounding Must Be Maintained

For equipment that requires grounding, the equipment-grounding conductor must remain continuous from the source through the cord to the equipment.

Never:

• Remove a grounding prong.
• Modify a plug so it will fit an incompatible receptacle.
• Bypass the equipment-grounding conductor.
• Use a damaged grounding-type plug.
• Assume that a repaired cord is safe without appropriate inspection and testing.

Double-insulated equipment does not rely on an equipment-grounding conductor, but the cord and plug must still be maintained in safe condition.

Protect Cords From Damage

Preventing cord damage is safer than repairing it.

• Do not run cords through doorways or other pinch points unless they are properly protected.
• Keep cords away from sharp edges, heat, oil, chemicals, and standing water.
• Do not use cords to hoist or lower tools.
• Never unplug equipment by pulling on the cord.
• Protect cords from vehicle and equipment traffic.
• Do not fasten cords with staples or other methods that could damage the insulation.
• Use cords rated for the environment and conditions in which they will be used.

Construction-site electrical systems must also use required GFCI protection or an assured equipment grounding conductor program, as applicable.

Inspect and Test After Repair

A repaired cord should not automatically be returned to service. Before reuse:

• Inspect the entire cord and repaired area.
• Verify that the plug or connector is correctly assembled.
• Check the strain relief.
• Verify grounding continuity when applicable.
• Confirm correct wiring and polarity.
• Perform any testing required by company procedures or the applicable electrical safety program.

If there is any doubt about the integrity of the repair, do not use the cord—replace it.

Remember

Electrical cords are safety equipment as well as power conductors. A makeshift repair can expose employees to shock, electrocution, or fire.

Remove damaged cords from service immediately. Repair them only when an acceptable repair can restore their required safety characteristics—otherwise, replace them.