Power strips ( Our EHS department is asking if power strips are allowed )

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GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Fire marshalls like metal plug strips. I found a source for model with 15 ft cord, ul listed. What you can't do is attach plug strip cord to wall.
correct name is temporary power tap.

To make sure that the temporary power tap is really temporary, you have to not only not tie down the power cord, you have to refrain from permanently attaching the power tap itself to the wall or floor. To allow you to hold the thing in place without violating that rule, the better power taps have keyhole slots so that you can remove them and reattach them without using tools once you have put the screws in place.

As apparently required by UL regulations, the manufacturers instructions for all of them prohibit daisy chaining power taps, i.e. plugging the cord of one into another power tap or receptacle multiplier.
 

paulengr

Senior Member
Not so much NEC which doesn’t care as OSHA has an issue with environment. They require GFCI in areas where the equipment is subject to frequent use/abuse or an assured grounding program. There is a ton of vagueness in this section. The result is we have two power strips. One kind is the typical residential grade one that may have a small circuit breaker or a surge protector. It might even have yellow plastic and be sold at a home improvement store but the price is still cheap. The other has a GFCI usually on every receptacle and is specifically intended for power distribution in an industrial or construction environment. UL testing is more strict and the price is a lot higher. A lot of plants mandate GFCI to comply so I carry a small one on every job for compliance. I get them from Grainger or a local farm store. Most are portable but some have slots for wall anchors.

The above two power strips have slots on the back so you can clip them onto screws but they are not permanent fixtures. A third type usually has.either no cord or a cord without a plug and mounting screws. It is basically a premade strip of receptacles for work benches, kitchens, and charging stations. This is really what you want anyways.

The whole issue with mixing power strips and/or extension cords is all about voltage drop. The cord itself is protected from overload and shorts by the protection for the receptacle. But excessive length causes voltage drop. It won’t hurt your cell phone charger but if I try to say run two light duty 100 foot drop cords for a heavy power tool the voltage drop will be so high that the tool will overheat and burn up. Think of it as trying to drink a milk shake with a coffee straw...you will probably burn up too trying instead of using a fat milkshake straw. Same principle with extension cords.

For a given size wire (gauge) extension cords have a maximum length for a reason. You won’t find any 100 foot 16 gauge light duty cords. You can either use the one cord rule or there are charts showing maximum length based on the load. At the end UL allows one power strip.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
There used to be a Mac computer store here that had a series of power strips run down each side of the office, I'm thinking between six and eight desks on each side of the room, each strip plugged into the last socket of the previous strip, and a desk placed by each strip. Clearly the epitome of a non-compliant installation.
 

Srv52761

Senior Member
Location
lowa
Occupation
Energy Manager
Bingo. I run into this frequently where a facility gets a fire inspection. I do not know exactly what these "codes" or standards are that a fire marshal cites, however they seem to be quite specific. Outlet strips are ok, but daisy chaining them or using extension cords is generally not. There are also restrictions that things with over a certain size motor or certain load can not be plugged into an outlet strip.

Checking how my school district’s employees used electricity was part of my job. Sometimes they got very creative in running cords, so the fire marshal and I were well acquainted. Yes this is under the guidance of the fire code.
”11.1.4 Relocatable Power Taps.

11.1.4.1 Relocatable power taps shall be of the polarized or grounded type with overcurrent protection and shall be listed.

11.1.4.2 The relocatable power taps shall be directly connected to a permanently installed receptacle.

11.1.4.3 Relocatable power tap cords shall not extend through walls, ceilings, or floors; under doors or floor coverings; or be subject to environmental or physical damage”.


They were perfectly fine for electronics and small appliances. Some fire marshals allowed them on refrigerators and microwaves, some did not.
Most would also flag those single outlet surge protectors, calling it a tap and without oc protection.

Citing these, along with the NEC quotes, usually kept the teachers from getting mad at me and “blowing a fuse” (pun intended) when I dismantled their elaborate jury-rigged wiring.
 

kwired

Electron manager
Location
NE Nebraska
What are you supposed to do if, for example, you have a music studio with a bazillion electronic gizmos that draw tiny bits of current and not all that many are operational at the same time? Having a wall outlet for each of them isn't reasonable, IMO.

That one occasional idiot that plugs a 1500 watt space heater into the power strip is who makes them dangerous. Even if they have a breaker it may hold, but the contacts may not handle that kind of load for extended periods. Same goes for cheap residential grade receptacles, but they don't write those up.

Those space heaters are convenient but still not a good idea for 5-15 cord connections period. But they won't sell if they don't have a 5-15 cord either. That connection was never designed for heavy duty loading. Short time loading at full rating isn't a problem, it is long time loading, even at only 50% in some cases that causes problems.
 
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