Guidelines for Flexible Electrical Cords
Note: For the
purposes of this document, a power strip is
defined as a multi-outlet adapter with a flexible
cord-and-plug attachment and an over-current device
(breaker). Some power strips also have a master on/off
switch and some have a surge suppressor.
OSHA, the National Electrical
Code (NFPA-70) and the Texas A&M University have
specific requirements for the use of flexible cords
No exception is made for the use of a flexible
cord that contains an over-current protection device
(such as a power strip or surge protector) instead
of a traditional plain extension cord.
Any flexible cord or cable, whether it is the
actual power cord from the electronic device, an extension
cord, or the cord of a power strip, can NOT be used:
a substitute for the fixed wiring of the structure
run through holes in walls ceilings or floors
run through doorways, windows or similar openings
attached to building surfaces
concealed behind building walls, ceilings, or floors.
for temporary wiring (as provided for in the National
Electrical Code, NFPA-70/NEC-305, not to exceed 90
days) cord-and-plug connection of equipment is not
permitted to be energized from extension cords.
cords are not legal substitutes for the NEC-compliant
fixed wiring of a structure such as a receptacle outlet.
Power strips are classified as temporary devices and,
as such, should never be permanently mounted to any
facility surface. Notice the fine print on the
package where it explains that the keyholes on the
back are for temporary hanging of the power
for Use of Power Strips and Extension Cords
Laboratory instrumentation and fixed equipment
that you cannot lift yourself should be plugged directly
into the wall outlet.
Exceptions will only be made for equipment
that needs a surge suppressor.
In this case, the surge suppressor should be
mounted to the outlet with the protected device directly
Power strips must meet the following criteria:
Use only surge protectors or power strips that have
an internal circuit breaker. These units will
trip the breaker if the power strip is overloaded
or shorted to prevent overheating.
Power strips should have a plastic external case rather
than a metal one. Homemade extension cords employing
metal outlet boxes (example shown below) are NOT acceptable.
Not Acceptable - Homemade
Frayed or strained cords are NOT permitted.
The surge protector or power strip should always
have either a polarized plug with one of the blades
being larger than the other one, or a three-prong
grounded plug. Never use a three-to-two prong
adapter to power the unit. Never cut off the
grounding prong of a 3-prong plug.
Not Acceptable – Missing Ground Prong
Only UL 1363, 1449 2nd edition, or 46D0 approved power
strips (those with over-current testing) should be
used on campus. Just because it is UL rated
does not mean that it is approved.
"Flexible" use power strips should have
a cord of no more than 6 feet in length. Power
strips with cord longer than 6 feet are classified
by code as power strip with extension cord. Longer
length extension cords are only for "temporary"
There should only be one surge protector or power
strip plugged into a single duplex electrical outlet.
Example: NOT Acceptable
Do NOT plug a surge protector or power strip into
an existing surge protector or power strip.
This practice is called "daisy-chaining"
or "piggy-backing" and can create a serious
Power strips should not be overloaded. Most
are rated for 15A. This equates to approximately
1500 watts of power connected to the device.
Surge protectors, power strips, and/or extension cords
are NOT a substitute for permanent wiring.
Do NOT locate a surge protector or power strip in
any area where the unit would be covered with carpet,
furniture, or any other item that will limit or prevent
Do NOT staple, tack, or tape a surge protector or
Personal computer use: Personal computers and
their accessories can be plugged into a power strip.
It is recommended for the protection of the equipment
that the power strip have surge protection.
If possible, the approved power strip should be elevated
off the ground. It should never be permanently
mounted to a building surface.
Bench top use of power strips on "wet" laboratory
benches will be permitted only under the following
There must be GFCI protection via 1 of the
following 3 methods:
Install GFCI rated breakers for a laboratory bench
area and use a UL rated surge protector.
Install a GFCI rated outlet and use a surge protector.
ii. Use a GFCI rated
surge protector for laboratory use operations
power strip should be hung on mounting screws above
the bench top.
strips are never acceptable for the following uses
unless GFCI equipped:
To power any water pumping equipment
Use in a damp location
Use in a cold room
Use near a sink or other source of water.
Use of extension cords and/or power strips in an area
that may contain flammable vapors (e.g. solvent storage
room, paint cabinet) is never permitted even with
GFCI. These environments require specially rated,
intrinsically safe power equipment to prevent explosions.
Equipment with a heating element should not be connected
to a power strip. This includes:
Extension Cord Construction
outlet adapters (“octopus adapters”) are
strip outlets that are fused for the wire size of
the connecting cord, are allowed when needed to power
extension cords shall contain a ground wire and shall
be constructed from type S, hard usage material. When
cords are used with heating appliances, a type HS
cord is required.
14-gauge wire is required in a flexible cord servicing
a current draw of more than 7 amps.
Extension Cord Use and
cords shall not be used as a substitute for permanent
cords shall not be used on stationary equipment or
equipment drawing more than 15 amps, such as refrigerators,
centrifuges, or power tools.
cords shall not run through, behind or in walls, ceilings
or floors or other concealed space. Nor shall they
be run in or through ventilation ducts.
place extension cords under carpets, under doors,
or other locations that subject the cord to abrasion
or other damage.
creating a tripping hazard; do not place extension
cords across walkways or doorways.
extension cords with broken wires or damaged insulation;
splicing or taping is not allowed.
hazardous atmospheres may exist, due to the presence
of flammable gases or vapors or explosive dusts, extension
cords shall not be used.
length of the appliance cord and extension cord that
is used on very portable equipment, such a floor scrubber,
projectors and hand tools, shall not exceed 105 feet.
General Safety Considerations
long cords when in use, to avoid overheating.
a short appliance cord with a longer one when appropriate.
the proximity of electrical outlets when locating
furniture. For example, move the furniture closer
to the outlet, rather than using a 50-foot extension
cord to bridge a 2-foot gap.
a cord with proper insulating materials if there will
be exposure to moisture, oil or other chemicals.
use, visually check the cord insulation, plug and
connector for damage.
further information on electrical safety, refer to:
Safety Manual, Chapter 5, Electrical Safety
Electrical Code (NEC), NFPA-70
Handbook of Electrical Safety, DOE-HDBK-1092-98