Multioutlet Assemblies (Plug Mold) (01-17-01)

UL Articles



Can a 15-ampere multioutlet assembly (plugmold) be installed on a 20-ampere circuit?

15-ampere multioutlet assemblies (UL-PVGT) are intended for use only on 15-ampere branch circuits.
Tom Lichtenstein, Ext. 42160
Staff Engineer, Regulatory Services Underwriters Laboratories Inc.

Mike Holt's Comments:

I personally spoke to Tom about this issue and I was shocked at his answer. I thought a 15-ampere multioutlet assembly would be permitted on a 20-ampere circuit because Table 210-21(b)(3) in the NEC permits 15-ampere receptacles (if more than one) to be on a 20-ampere circuit. Tom's response was that if the multioutlet assembly used a No. 12 wire instead of a No. 14 wire, then the assembly should have a current rating of 20-amperes.

Now I am curious. What size conductors are typically used in multioutlet assemblies? If any of my e-buddies have a multioutlet assembly lying around, would you let me know? What size wire is used between the 15-ampere receptacles?

While we're at it, do they sell (make) listed multioutlet assemblies with 20-ampere receptacles? If they do, what size conductor is used between the 20-ampere receptacles? Are there any markings on multioutlet assemblies as to the maximum circuit the assembly can be installed on?

Response No. 1:

I just heard from the Wiremold rep. He confirmed what I said in my E-mail to you the other day. Wiremold is wired with 12-AWG conductors and is available with 15 or 20-ampere receptacles. So, it would seem to me that even if you used the Wiremold with 15-ampere receptacles, it would be permitted to connect that to a 20-ampere branch circuit. I suppose it is possible that another manufacturer might use 14-AWG for their 15-ampere plugmold, and 12-AWG for their 20-ampere plugmold.

Now I have a simple question for you. A contractor asked, "How do I install a GEC for a large service on an industrial building? The service in the rear of the building is about 400 feet from the front of the building where the main water service comes into the building. Do I have to run the GEC all the way to make the connection to the first five feet of the water main? The building is of steel construction.

Must the GEC be run to the first five feet, or is there some other way to do it? Four hundred feet is an awful long way to run the GEC. What about voltage drop on the GEC for such a long run? Thanks for your ideas.
Ray C. Mullin,

Response No. 2:
RE: "plugmold" - I looked at a section I had on hand. It is 15-amp rcptl with No.12 wire. From the Wiremold Catalog - 2000 Plugmold: The harness shall consist of 15A, 125V spec grade receptacles, factory wired with No.12-AWG-typeTHHN conductors to enable use on 20A branch circuits. This is from a 1992 catalog. We don't use Wiremold much anymore.
Tom Baker

Response No. 3:

The 15-amp multioutlet assembly comes with a 14-AWG wire. I haven't seen any assembly with a 12-AWG. I guess you can special order them but it's not a common item.
Clifford Rambaran, TSgt,

Response No. 4:

We have No. 12 wire in our assemblies and the catalog lists only No. 12, but only 15A rcpt in a multi of length No. 20A.

Gene Farmer

Response No. 5:

I opened a couple of old plugmold assemblies a few months ago but I don't know how old they were. We replaced them because of damage done to them. I was quite surprised to find No. 16 between the outlets.


Response No. 6:

The plugmold we've used has 12 solid between the outlets.

Response No. 7:

I never looked for any markings or ratings on a multioutlet assembly/plugmold. The ones I installed were on 20A circuits. The receptacles were 20A and the wire running through the assembly was always 20A. However, I have always felt the individual connections to the receptacles were a little questionable. The wires are "stabbed" by sharp points as they pass the receptacles. If each receptacle is rated 20A, how can this kind of connection be good enough? I thought "backstab" residential receptacles were bad enough. This seems worse!
Chris White

Response No. 8:

I am responding to your inquiry regarding multioutlet assemblies listing requirements. I have the following product, which has been lying around in my shop for several years because the toggle switch failed.
1) The nameplate information is as follows:

2) Personal Observations:
The three duplex receptacles are rated at 15-amperes- The internal wiring is No.14. The circuit breaker has the following label- ELECTRICAL PRODUCTS INC., JACKSON, MICH 1600-117-150, 125/250 VAC 2483 - The reverse UR symbol and the CSA symbol. No specific evidence of a current rating. This device appeared to be well-made using quality components.

I hope that this one data point together with others that you gather will be helpful. I am looking forward to the conclusions reached after you collect all of the responses.
Dr. Dale Rummer,

Response No. 9:

On somewhat of a related UL note... A few years back, I wrote to UL asking them to confirm my suspicion that a UL listing does not necessarily mean compliance with the NEC. They confirmed it. Here's the issue:

My circular saw has a nameplate of 115 volts and 13-amps. The saw has a NEMA 15-amp plug and is UL listed. The NEC states that any cord-connected load shall not exceed 80% of the branch circuit rating (see postscript). Eighty percent of 15-amps is 12-amps. Therefore, connecting the saw to a 15-amp circuit seems to be a code violation.

I received a letter back from UL laboratories indicating that compliance with the NEC was not a prerequisite to receiving a listing. Looking at it from the other direction, the NEC takes a 'hands off' approach to anything that is listed. Therefore, it can be interpreted that the NEC only applies to installations, not listed assemblies. Now, if one were to build a multioutlet assembly using parts from a hardware store, code compliance becomes an issue because this is most certainly not a listed assembly.

Table 210-21(b)(2) shows this. 210-23(a) specifically states "The rating of any one cord and plug connected utilization equipment shall not exceed 80 percent of the branch-circuit ampere rating."
Eric Stromberg,

Response No. 10:

Just a few comments on 15-amp multioutlet assemblies, which I take to mean plugmold and similar, such as made by Wiremold. I have frequent occasions to specify data and wire raceways and plugmold for computer installations. Often, for capacity reasons, I need two 20-amp circuits in the raceway or plugmold and I'm annoyed that Wiremold does not offer plugmold hardware in full 20-amp capacity wire and does not offer the double neutral that is needed for harmonic currents in polyphase installations. I spoke to my Wiremold sales rep several times on the matter and he said he would take it up with the factory staff to add the double neutral to their product line. The result has been the same sound as one hand clapping. I no longer use their plugmold and now use only dual-channel raceway, such as Panduit or Wiremold for harmonic producing loads.

I got the same lack of response on the issue of the 15-amp wire in plugmold when I pointed out numerous times that commercial grade wiring is almost always full 20-amp minimum.

I hope others have additional comments for your subscribers.

Kevin Cassidy

Response No. 11:

I have a 20-ampere assembly that has No. 12 wire.
Daniel Vance,

Response No. 12:
According to the specification in the Wiremold catalog, plugmold 2200 comes factory-wired with No. 12 THHN conductors "to enable use on 20A branch-circuits."
P. J. McGuire,

Response No. 13:
I have only seen No. 12 Cu [THW for older, THHN for newer] conductors on "plugmold" strips, which have 15-amp receptacles. This is true of the strips with receptacles at 6-inch centers and 12-inch centers. I don't recall seeing any 20-amp receptacles, so I'll ask around and check out plugmold at our wholesale house.

Scott E. Thompson,

Response No. 14:

At our facility, we have primarily Wiremold products installed varying in age from 15 years to new. In all I have encountered, 12-gage wire is used. We have both 15 and 20-amp receptacles in pre-fab and onsite fabrications of surface raceways. The Wiremold catalog I have (1991) does note the applicable section of the NEC for derating ampacity of conductors when more than three conductors are contained in a raceway (Tables 310-16 through 310-19). One note is the derating factors do not apply to conductors installed in surface raceways when all conditions of Article 352-4 are met. I mention this for multicircuit plugmold applications.
Hope this helps.
Trip Tollison

Response No. 15:

I am looking at a Wiremold catalog. They show 15-amp, 120-volt, (NEMA 15R) receptacles for one series using 12-AWG THHN conductors. They show 20-amp, 120-volt, (NEMA 20R) receptacles for another series using 12-AWG THHN conductors. I cannot find 14-AWG conductors in their plugmold series. I put in a call for the Wiremold rep. He is on vacation, so I will try to reach him again next week.
Ray C. Mullin

Response No. 16:

I found a plugmold multioutlet assembly manufactured by Brooks, model A-506, with 10-15-amp spec grade receptacles. Conductors inside are No. 12 THHN/THWN. Sticker on the back says, "to be used with not more than two additional conductors No. 14 or No. 12-AWG. Types TW, THHN or THWN conductors 15A, 125V". I thought they could only be used on 15-amp ckt. An additional question I have is do they have to be hard wired to circuit or can you put a cord on them with a plug?
Steve Spooner,

Response No. 17:

You aroused my curiosity. I went to our warehouse and found several pieces of multioutlet assembly wireways of different brands. I didn't see any 20-amp rated receptacles though but all the different pieces lying around had No. 12 wire installed in them.
Fred Madden,

Response No. 18:

Page 735 of the current W.W GRAINGER catalog shows both 15 and 20-amp versions spec'ed with 12- ga and 15-amp NEMA 5-15 receptacles.