Extension cords wiring

[faresos]

We have a situation where we are using many twist locked receptacles located above at the ceiling in classrooms area with a yellow factory pre-made SO cord cable with a twist lock on one end (above) and (2) Nema 5-20R duplex receptacles on the other end (drop down). The purpose of this wiring is to give the owner felxibility to power a cluster of computers and monitors. The inspector have said Reloadable Power taps are not intended to be used in series connected (daisy chained) to other relocatable power taps or to extension cords. My questions:

1. Can power strips be plugged into thses two receptacles?Or would this configuration be considered "Daisy-chaining"?
2. Would this yellow cord be defined as an "extensior cord"?
3. Is a twist lock considered "Hard-wired"?

Your thought is really appreciated. Thanks,

 

[eric9822]

We have a situation where we are using many twist locked receptacles located above at the ceiling in classrooms area with a yellow factory pre-made SO cord cable with a twist lock on one end (above) and (2) Nema 5-20R duplex receptacles on the other end (drop down). The purpose of this wiring is to give the owner felxibility to power a cluster of computers and monitors. The inspector have said Reloadable Power taps are not intended to be used in series connected (daisy chained) to other relocatable power taps or to extension cords. My questions:

1. Can power strips be plugged into thses two receptacles?Or would this configuration be considered "Daisy-chaining"?
2. Would this yellow cord be defined as an "extensior cord"?
3. Is a twist lock considered "Hard-wired"?

Your thought is really appreciated. Thanks,

From the 2012 UL Whitebook
Relocatable Power Taps (XBYS)
Relocatable power taps are intended to be directly connected to a permanently installed branch circuit receptacle. Relocatable power taps are not intended to be series connected (daisy chained) to other relocatable power taps or to extension cords.

Your yellow cord sounds like an extension cord to me.

A twist-lock connection is not a hardwired connection.

 

[iwire]

It also sounds like the cords go above the ceiling which is an NEC violation

 

[petersonra]

We have a situation where we are using many twist locked receptacles located above at the ceiling in classrooms area with a yellow factory pre-made SO cord cable with a twist lock on one end (above) and (2) Nema 5-20R duplex receptacles on the other end (drop down). The purpose of this wiring is to give the owner felxibility to power a cluster of computers and monitors. The inspector have said Reloadable Power taps are not intended to be used in series connected (daisy chained) to other relocatable power taps or to extension cords. My questions:

1. Can power strips be plugged into thses two receptacles?

It is probably not in compliance with the UL listing to do so.

Or would this configuration be considered "Daisy-chaining"?

I don't believe this term is defined or used in the NEC.


2. Would this yellow cord be defined as an "extensior cord"?

As described I think it is probably an extension cord. It could probably be hard piped at the top to be a drop cord and thus not an extension cord.

3. Is a twist lock considered "Hard-wired"?

Not IMO. A twist-lock is just another style of plug.

Your thought is really appreciated. Thanks,

How did the inspector ever find out about the plug strips anyway?

I am not convinced what you are doing is unsafe, or even inadvisable, but it probably does not meet code requirements.

 

[faresos]

How did the inspector ever find out about the plug strips anyway?

I am not convinced what you are doing is unsafe, or even inadvisable, but it probably does not meet code requirements.

The inspector assumption was since there will be a cluster of PC's and monitors that will require more than 4-plugs on a table then the user for sure would use a power strip to power these extra equipment. The thing is, we have a dedicated circuit for each twist lock receptacles and these outlets will be used as needed (its not like a permanent installation where they have PC's on work stations, it?s just like a lab.

 

[faresos]

It also sounds like the cords go above the ceiling which is an NEC violation

Actually there is no ceiling, its exposed ceiling.

 

[petersonra]

The inspector assumption was since there will be a cluster of PC's and monitors that will require more than 4-plugs on a table then the user for sure would use a power strip to power these extra equipment. The thing is, we have a dedicated circuit for each twist lock receptacles and these outlets will be used as needed (its not like a permanent installation where they have PC's on work stations, it?s just like a lab.

Unfortunately, while it is not likely unsafe, it seems like the inspector "gotcha".

OTOH, I see no way he can red tag you unless there is an actual violation at the time of an inspection. He cannot red tag you for something that might happen down the road. If there are no power taps plugged in right now, there is no violation.

 

[jeremysterling]

It also sounds like the cords go above the ceiling which is an NEC violation

That is what I thought at first. After rereading, the OP states the twistlock recepts are "at" the ceiling, which gives me the impression of flush-mounted recepts.

Unfortunately for the OP, I will agree with everyone who has posted.

I think the solution the inspector will accept will be a Relocatable Power Tap with a long cord and male twistlock cordcap.

 

[fmtjfw]

We have a situation where we are using many twist locked receptacles located above at the ceiling in classrooms area with a yellow factory pre-made SO cord cable with a twist lock on one end (above) and (2) Nema 5-20R duplex receptacles on the other end (drop down). The purpose of this wiring is to give the owner felxibility to power a cluster of computers and monitors. The inspector have said Reloadable Power taps are not intended to be used in series connected (daisy chained) to other relocatable power taps or to extension cords. My questions:

1. Can power strips be plugged into thses two receptacles?Or would this configuration be considered "Daisy-chaining"?
2. Would this yellow cord be defined as an "extensior cord"?
3. Is a twist lock considered "Hard-wired"?

Your thought is really appreciated. Thanks,

Here's what we did for computer tables in classrooms:

1) 20A 120V twistlock plug into receptacles in 4x4s (on walls)
2) 3-12 SO cable from plug to plastic 1 gang box mounted on table
3) 5'6" of nonmetallic plug strip fed from box and mounted on table
4) 2nd 1 gang plastic box mounted on table
5) 20A 120V twistlock receptacle in box.

We did daisy chain these tables as required.
Left and right versions as required by room layouts.

 

[eric9822]

Unfortunately, while it is not likely unsafe, it seems like the inspector "gotcha".

OTOH, I see no way he can red tag you unless there is an actual violation at the time of an inspection. He cannot red tag you for something that might happen down the road. If there are no power taps plugged in right now, there is no violation.

I agree. It's probably perfectly safe. This is also something I would expect a safety manager to flag, not an electrical inspector. If the receptacles are mounted code compliant then I don't see how they could be red tagged.

 

[iwire]

Here's what we did for computer tables in classrooms:

1) 20A 120V twistlock plug into receptacles in 4x4s (on walls)
2) 3-12 SO cable from plug to plastic 1 gang box mounted on table
3) 5'6" of nonmetallic plug strip fed from box and mounted on table
4) 2nd 1 gang plastic box mounted on table
5) 20A 120V twistlock receptacle in box.

We did daisy chain these tables as required.
Left and right versions as required by room layouts.

I will be honest, that sounds like the kind of job we would be sent in to rip out and do over after a fire department inspection. The fire departments around here hate to see cords.

 

[fmtjfw]

I will be honest, that sounds like the kind of job we would be sent in to rip out and do over after a fire department inspection. The fire departments around here hate to see cords.

That's odd, what does your fire department cite as a problem in using cords and plugs to provide power to portable, movable tables?

Each year the principal or teacher decides that the educational experience of the students will be enhanced by rearranging the computer room.

We had one guy who wired these tables with BX, it was a real pain to rip it out each year when the tables needed to be moved to enhance the educational experience. The summer floor crews also hated it. With the plug and cord system they could unplug everything, move the tables to one side of the room, do half the floor ....

 

[iwire]

That's odd, what does your fire department cite as a problem in using cords and plugs to provide power to portable, movable tables?

The FD rarely cites anything, they just make it happen.

I would expect they would be fine with listed powered tables pluged into permenant chapter 3 wiring methods.

 

[faresos]

That is what I thought at first. After rereading, the OP states the twistlock recepts are "at" the ceiling, which gives me the impression of flush-mounted recepts.

Unfortunately for the OP, I will agree with everyone who has posted.

I think the solution the inspector will accept will be a Relocatable Power Tap with a long cord and male twistlock cordcap.

Actually thats what I have at the other end, a twist-plug at one end that connect to twist lock receptacles mounted above and the other end of the drop down cord is a duplex receptacles (or in some cases 2-duplex receptacles). Would that consider to be an extension cord or relocatable power tap that we can not plug power strip to it? we have hundreds of those installed at this project

 

[WorkSafe]

OSHA's standard at 29 CFR ?1910.303(b)(2), Installation and use, requires that "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." Manufacturers and nationally recognized testing laboratories determine the proper uses for power strips. For example, the UL Directory contains instructions that require UL-listed RPTs to be directly connected to a permanently installed branch circuit receptacle; they are not to be series-connected to other RPTs or connected to extension cords. UL also specifies that RPTs are not intended for use at construction sites and similar locations.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=24631

You are essentially using a extension cord plugged into the ceiling receptacle to power your tables via a RPT. This is not allowed.