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Piggy backing of power strips #91267
01/08/05 06:59 PM
01/08/05 06:59 PM
MikeP  Offline OP
Junior Member
Joined: Sep 2004
Posts: 6
Astoria, OR USA
I have a question that I cannot find the answer to so hopefully you folks can help. I have searched and searched but there is not answer that I can find.

Why should you not Piggy back or Daisy chain power strips?


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Re: Piggy backing of power strips #91268
01/08/05 09:25 PM
01/08/05 09:25 PM
gfretwell  Offline

Joined: Jul 2004
Posts: 9,366
The obvious answer is overload but if they all have overload protection I don't have an answer

Greg Fretwell
Re: Piggy backing of power strips #91269
01/08/05 09:28 PM
01/08/05 09:28 PM
Bill Addiss  Offline
Joined: Oct 2000
Posts: 3,905

According to the UL 'White Book' this would be a violation. I have Highlighted a section for emphasis:
Relocatable Power Taps

Guide Information for Electrical Equipment for Use in Ordinary Locations

This category covers relocatable power taps rated 250 V ac or less, 20 A or less, intended for indoor use as relocatable multiple outlet extensions of a branch circuit to supply laboratory equipment, home workshops, home movie lighting controls, musical instrumentation, and to provide outlet receptacles for computers, audio and video equipment, and other equipment . They consist of an attachment plug and a length of flexible cord terminated in an enclosure in which one or more receptacles are mounted. They may, in addition, be provided with fuses or other supplementary overcurrent protection, switches, suppression components and/or indicator lights in any combination, or connections for cable, communications, telephone and/or antenna.

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.

Relocatable power taps are not intended for use at construction sites and similar locations.

Relocatable power taps are not intended to be permanently secured to building structures, tables, work benches or similar structures, nor are they intended to be used as a substitute for fixed wiring. The cords of relocatable power taps are not intended to be routed through walls, windows, ceilings, floors or similar openings.

For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ).

The basic standard used to investigate products in this category is UL 1363, "Relocatable Power Taps."

The Listing Mark of Underwriters Laboratories Inc. on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the UL symbol (as illustrated in the Introduction of this Directory) together with the word "LISTED," a control number, and one of the following product names, as appropriate: "Relocatable Power Tap," "Power Tap" or "Outlet Strip."

Re: Piggy backing of power strips #91270
01/09/05 10:56 AM
01/09/05 10:56 AM
PCBelarge  Offline
Joined: Jun 2003
Posts: 681
Dobbs Ferry, NY, USA
When I teach code classes, I hold up a copy of the UL White Book and tell the class that without that document, they will have a very difficult time with certain installations. The NEC requires listing, the UL White Books tells one what the listing is (or the packaging of the product itself).
It should be sold or provided as a companion to the NEC.

I just ran into a situation for a National Chain store where they were "daisy chaining" power strips to avoid installing new receptacles. I printed a copy of the UL wording and in a couple of days there were new receptacles [Linked Image].


Pierre Belarge
Re: Piggy backing of power strips #91271
01/09/05 04:16 PM
01/09/05 04:16 PM
Bill Addiss  Offline
Joined: Oct 2000
Posts: 3,905

I thought the same thing, that the listing info should accompany the NEC. I think the CEC (Canadian Code) is like that.

My understanding is that the source of the listing (doesn't have to be UL) is up to the AHJ, so combining the UL Directories with the NEC may not give a complete source of info anyway.


Re: Piggy backing of power strips #91272
01/09/05 07:50 PM
01/09/05 07:50 PM
George  Offline
Joined: Feb 2002
Posts: 375
As I understand the issue ...

Each power strip allows plugs to be inserted into its recepticles. The only restruction is that the plug be 15amp.

Each power strip allows its plug to be inserted into any 15amp receptical. The recepts on power strips are rated at 15amps.

There is no code violation in daisy chaing power strips.

The words in the listing "not intended" does not mean "not permitted."

Re: Piggy backing of power strips #91273
01/09/05 08:54 PM
01/09/05 08:54 PM
Ryan_J  Offline
Joined: Aug 2003
Posts: 1,374
West Jordan, Utah, USA
George: Relocatable power taps are not within the scope of the NEC, so there can be no possible way to violate the NEC, even if the langauge backed it up in the white book.

With that said, I would still turn it down as a code official, becasue they are not intended to be used in that manner. I would cite it as a provision of obtaining a business license, as it is a fire hazard.

Ryan Jackson,
Salt Lake City
Re: Piggy backing of power strips #91274
01/10/05 12:33 AM
01/10/05 12:33 AM
gfretwell  Offline

Joined: Jul 2004
Posts: 9,366
I came here from the computer industry and we saw a lot of that "strip" abuse, The problem was we would have a whole rack of modems that draw a fraction of an amp each and all had a plug.
The universal answer we got from the fire marshal was that he didn't care as long as all the strips had breakers in them. They hated cube taps and unprotected strips.

Greg Fretwell


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