(2) Total Cord-and-Plug-Connected Load. Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cord-and-plug-connected load in excess of the maximum specified in Table 210.21(B)(2).
Table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle
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
USE 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.
INSTALLATION 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.
ADDITIONAL INFORMATION For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ).
REQUIREMENTS The basic standard used to investigate products in this category is UL 1363, "Relocatable Power Taps."
UL MARK 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."
I believe the outlet strips were classified as extension devices and only allowed as a "temporary" connections such as the extension cord. When people began to complain, U/L and other labs tested these devices in a different manner and now can be used as the listing has stated. A lot of requirements are not contained in the NEC, but have to be researched in other directories. The temperature limitations of terminals and conductors were in the U/L White Book long before the NEC saw a need to publish it in their code.
I recently visited a plant in the St. Louis area that the IT department had about three or four of these daisey-chained together. Only computers were plugged in, no printers, so they didn't trip the breaker. Our team leader pointed this out to the owners, but to no avail because the whole department is relocating soon. And this is one of the relocation reasons given, not enough receptacles and circuits in the present location. Another thought. Although UL says it is a violation, most communities adopt ONLY the NEC which then has the force of law behind it.
Temporary is such a relative term, isn't it? Mine does get unplugged several times per year when going away or during severe storms, but aside from that it stays where it is. So, .. one might say that it was 'Perpetually Temporary'
Re: multiple outlet strips#7326 07/03/0610:48 AM07/03/0610:48 AM
As you described, I have one right in front of me that is called a "Temporary Power Tap"
I have two lying here in front of me, one in use, one whose plug was a dog-treat. One is the older metal style with the replacable receptacles (and a 10ft power cord), the other is a modern Leviton plastic model. None of them say "Temporary Power Tap." They both say "Relocatable Power Tap," and are UL Rated as such.
(Edited a 1001 times to make the QUOTE thingy work.)
[This message has been edited by Theelectrikid (edited 07-03-2006).]
Is there anyone on board who knows how to fly a plane?
I think we're -again- confusing two different UL classifications.
"Temporary power strips" are one thing, and intended for temporary use. NEC defines temporary as 90 days or less.
However, similar looking strips, with surge suppressors, are listed to a different UL standard, and are allowed for "permanent" use. They are still not intended to be "daisy chained," though. From a practical standpoint, even though the little breaker might say "15 amps," they really aren't stout enough to carry that kind of load for any length of time. In practical terms, 5 amps would be a more realistic load; the breaker is only there should something bad happen.