Power strips daisy chained???

Old 03-31-17, 01:29 PM
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Power strips daisy chained???

A friend showed me his new, huge, self built display case/wall unit, and it was beautiful. That said, for some reason he had this electrical set up: each shelf had at least one LED under cabinet/shelf light. Okay, but each of the 18 shelves shelf light had it's own cord, some of which were plugged into a power strip, said strip was plugged into another power strip, then a third, which was plugged into a wall receptacle.
I asked him about the unusual (to me) set up, and he agreed that it was "strange", but that the total watts of his lights was just under 100 watts.

It sounds safe, but is it?
Old 03-31-17, 01:52 PM
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Can't say if it's safe or not or if it's to code (I doubt it) Each connection is a point of failure. You be the judge.
Old 03-31-17, 02:08 PM
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Normally when a case like that is built..... low voltage LED's are used requiring smaller connecting wiring and one or two 12v convertors.
Old 03-31-17, 06:19 PM
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I can't quote the source, but daisy chained power strip are prohibited. Might be the UL standard .
Old 04-01-17, 05:10 AM
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Plugging a power strip to another power strip is prohibited. However, it should be safe as long as only the lights are on it.
Also, if a quality power strip with built it over current protection is used, it will be safer.
Old 04-01-17, 06:47 AM
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This idea had its roots with UL and then got picked up by OSHA:

One nationally recognized testing laboratory, Underwriters Laboratories (UL), refers to power strips as Relocatable Power Taps (RPTs) and, in its "General Information for Electrical Equipment Directory" (sometimes called the UL white book or UL Directory), describes RPTs 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."

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.

I don't think the OP has a safety issue with that install.
Old 04-02-17, 05:49 AM
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May not be a safety issue but how about them being all daisy changed together and not connected directly to an outlet?
Just curious
Old 04-03-17, 10:38 AM
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I can only think of this:

There is a growing risk of causing a high resistance grounding situation. If you have a bad 3rd wire ground at a receptacle/plug interface, only one device is affected. It you allow a factory to daisy-chain a dozen power strips and you lost the ground contact at strip number 4, all the downstream devices become ungrounded. And worse, a single bad device could "light up" lots of other devices.
And, the detection of this problem is not obvious to most users.

Now, even hospitals can use certain power strips, including in patient care. In their case, the strip MUST be fastened, with a tool, to a cart, rack, etc.

In non-health care situations, the power strip MAY be fastened down, but it MUST be removable without a tool.

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