Guidelines for Extension Cord Use

Extension cords are only to be used for temporary purposes. They do not replace the need for installation of outlets and proper wiring where necessary

Many questions have arisen regarding the restrictions on extension cords on campus. The following guidelines should be used by students and staff to assure that the extension cords in use do not violate good safety practices or fire codes. The National Electric Code (NEC) is the primary document that provides guidance in the use of extension cords. These guidelines are based on the NEC.

In dormitories and office settings:

1. Extension cords which have the UL label are approved, so long as the size and use is appropriate.
2. Two and three conductor extension cords must have a minimum conductor size of 16 AWG copper.
3. Extension cords are normally rated in amps, and must be used within the ampere rating. (Compare the ampere rating of the appliance with the rating of the chord.)
4. Three pronged (three conductor) extension cords must be used when connecting electrical items that have three pronged plugins.
5. Extension cords must not be run under rugs, mattresses, through doorways or windows, and must be protected from damage at all times.
6. Three prong adapters are not to be used with two conductor extension cords on the female end of the cord. Adapters used on the wall outlet must be installed with a metal screw installed in the outlet. (Contact Facilities Management for these installations. x6.7570)
7. Splicing and "home repairs" of extensions cords are not permitted unless performed by Facilities Management. Insulation, strength and conductor size must not be compromised.
8. Cords used in wet and/or outdoor locations should be protected by ground fault circuit interrupters.

On maintenance and construction sites:

1. Extension cords with an equipment grounding conductor must be used at all times.
2. Extension cords must be protected from damage, and not run through doorways or windows where the doors or windows may close, causing damage to the cord.
3. Extension cords must be plugged into a circuit protected by a ground fault circuit interrupter on wet or outdoor construction and maintenance sites, or have the ground circuit checked for continuity in an assured grounding and conductor program.
4. Extension cords should be a minimum of 16 AWG and be rated for the equipment in use. The following is a guide that might be helpful in selecting the cord:

Extension Cord Ampere Rating

Wire Size (Copper) Single Phase Two and Three Conductor Cords Three Phase Cords 16 AWG 13 amps 10 amps 14 AWG 18 amps 15 amps 12 AWG 25 amps 20 amps 10 AWG 30 amps 25 amps 8 AWG 40 amps 35 amps 6 AWG 55 amps 45 amps 4 AWG 70 amps 60 amps 2 AWG 95 amps 80 amp

5. Splicing extension cords must be done in such a way that the insulation and conductivity of the wires are not compromised.
6. Extension cords should not be run through water or allowed to have connections that may be exposed to puddling water.

For more information contact: Robert Burke, University Fire Marshal at 410.706.3494.

OSHA Link (Electrical)