Multiple power strips daisy-chained, code?

Hello Folks,

The fire marshall wasn't happy with daisy-chained power strips at church. There is only low power stuff hanging off of them and we need the 2nd one for those big wall warts (wider spaces, more stable). The first strip doesn't have enough slots anyhow and you can't get partially switched power strips with remote switch any other way. Only the first one has surge protection.

Anyhow, are there "official" regs, codes and whatnot that talk about this situation?

--
Regards, Joerg 

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Reply to
Joerg
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Our safety folks go ape droppings when they see that. Apparently it's something their mothers warned them about.

Cheers,

Phil Hobbs

Reply to
Phil Hobbs

If you go to an electrical supply store (not Home Depot), but a real electrical supply, you can buy a channel in which you can make a power strip any length that you want, and the outlets are spaced wide, to accomodate those big transformers for many electronics. (I personally wish they would change the design of those transformers so they used a regular cord and plug, and put the transformer end at the device, or in the center of the cord). Anyhow, you buy the channel, and put standard outlets into it. Then you wire it and use at least a #14 cord. You may need an electrician to wire it, or at least inspect it, but most churches have at least one electrician who is a member, so that should not be a problem.

I think these channel strips are made by Wiremold. Check their website at Wiremold.com. There may be other manufacturers too.

I made one of these for my work bench. I have an 8 foot strip along the rear of the bench, with 8 duplex outlets, powered with a #12 cord to match the 20A breaker I have on the circuit. This way I dont have to keep unplugging tools. I can leave my bench grinder, drill press, chop saw, sander, and all the other tools plugged in all the time. If I want to unplug these tools because of children or whatever, I just unplug the whole strip rather than unplugging multiple tools. This saves wear and tear on plugs and cords too.

LM

Reply to
letterman

No you cant do that, It violates overload conditions. Search for 'Relocatable power taps'

Cheers

Reply to
Martin Riddle

More likely the fire marshall doesn't really understand the issue, and has merely been trained that daisy chaining of power strips is a no-no.

And, of course, there's always the danger that someone who also doesn't understand the issue will unplug some of the low powered gear, and plug in some high powered equipment instead.

Sylvia.

Reply to
Sylvia Else

If you have a "Big Lots" store in the area, they have a really nice 4' long power strip with a dozen evenly spaced outlets. They're perfect for PCs and associated wall warts. I have one in my garage for the bazillions of battery chargers for my cordless power tools.

See your town or building inspector for their official regs, but they generally use some form of the National Electrical Code, published by the National Fire Protection Association.

In general, extension cords and power strips are for "temporary" use only. Permanent installations should have the outlets hardwired (yeah, right).

Reply to
krw

Well, we didn't want this to turn into a science project but we may have to. Thing is that we want to turn all but two outlets off with a switch and those two must remain on. Plus all of them surge protected. The power strip we have now has a lighted switch on a long cable that we mounted in a convenient position. But the man didn't like it.

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Regards, Joerg

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Reply to
Joerg

I don't see why. They claim that they are not rated for high current but ours are. They are rated for the full circuit breaker current. I still don't see the problem.

Even that should not be a problem if all strips are rated 15/20A. If you exceed the max total load the breaker goes. Just like if you had plugged it into a normal outlet.

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Regards, Joerg

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Joerg

Well, we must surge protect plus switch a partial panel of switches while not switching some others.

Then why do most have screw mounting features on the back _and_ a UL blessing?

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Regards, Joerg 

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Reply to
Joerg

Most safety folks do but not one was ever able to explain to me exactly what could go wrong, provided all strips are capable to handle full circuit current.

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Regards, Joerg

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Reply to
Joerg

** Such a home made contraption would violate safety regulations in any place I know of.

Mains power accessories, extensions leads and multi-way outlets etc are all required to be agency approved before going on sale - PLUS the latter must all have a suitable circuit breaker included in the active line.

...... Phil

Reply to
Phil Allison

Power strips are considered so dangerous that some jurisdictions with stiffest fire codes do not permit them. The concept is simple. If one power strip can provide enough connections, then more wall receptacles are necessary.

One power strip is considered an optional (some consider only temporary) solution. If so many permanent connections are necessary, then more wall receptacles are needed.

If current exceeds the 15 amp rating (those power strips should never be 20 amp fused), that is safety? Circuit breaker is your emergency backup protection. Others have defined that circuit breaker as primary protection. Primary protection is to not daisy chain power strips. That circuit breaker is only emergency backup protection. Inspector was correct especially in a building that may contain so many people and that might be empty (unsupervised) for long periods.

Narrower wall warts? See many new designs such as products from CUI Inc. Why did your appliance manufacturer not use this?

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Or buy special (UL approved) power strips designed with wider separation.

Every power strip must have a circuit breaker for an always necessary additional protection layer.

Meanwhile, that surge protector did not provide and does not claim to provide surge protection. If in doubt, post the numeric spec that claims such protection - and good luck. Effective protection has always been at the breaker box where surges are earthed before entering the building. That is surge protection for everything at much lower cost. Surge protectors that provide surge protection make a typically 'less than 10 foot' connection to earth. Such protectors even remain functional after every surge meaning nobody even knew the surge existed. Ineffective protectors fail.

Will that silly little power strip stop what three miles of sky could not? Of course not. And yet that is what the power strip must do. How will it absorb all that energy and remain functional (as effective protectors have done even for 100 years)? That power strip does not. And finally, scary pictures of another problem seen by most fire departments:

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If protection is needed, then upgrade (at little cost) building earthing to meet and exceed post 1990 National Electrical Code. Then install one 'whole house' protector that actually provides surge protection for everything. That solution is even simpler than installing more wall receptacles. Responsible companies such as Siemens, Leviton, Intermatic, Cutler-Hammer (Eaton), Square D, and GE provide these effective solutions.

Reply to
westom1

I have almost 50 things plugged in 24/7, just in my own office. That's a lot of receptacles for one room.

Best regards, Spehro Pefhany

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"it\'s the network..."                          "The Journey is the reward"
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Reply to
Spehro Pefhany

The problem with these is that the problem remains. Look at the blades, they need to be rotated 90 degrees.

Reply to
Anthony Fremont

The thought is that at some point someone will put 10 amps load on the first strip, then put 10 amps load on the second, and because the first strip is rated at 13 amps (typically) all heck will break loose.

Reply to
PeterD

13A? I don't think that UL would give such a power strip a blessing. I just looked at the strip here under my desk, it is rated at 15A and UL registered. The instant the user would plug in the 2nd 10A load the mains breaker would trip because it will not allow more than 15A total.
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Regards, Joerg

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Reply to
Joerg

Two strips + surge suppressor.

"UL" is required for temporary use too. UL NFPA. NFPA is the controlling authority in most jurisdictions.

The UL approved mounting holes won't catch on fire. ;-)

Also note that "UL" is often counterfeited.

Reply to
krw

Typically, each contact on a strip won't be rated for the full load of the strip, which is what you're asking from inline strips.

Reply to
krw

At least the ones I know look just like the contacts on a regular wall outlet. And they should. If I was a UL inspector I would flag and refuse a product that has sub-par amperage on individual outlets. What would prevent a consumer to plug a space heater or a vacuum cleaner into a power strip?

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Regards, Joerg

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Reply to
Joerg

I agree completely with that, and will add a suggestion that the meter base outside is a better place for the whole house surge supressor than your main panel inside the house. No panel space is used up, and the repairs are cheaper when an outside surge supressor explodes.

A few years back a storm caused a ~47kV line to contact a ~4.7 kv line feeding around 100 houses near here. Around half of the houses had utility installed surge supressors in the meter bases; all of these meters were blown out of their sockets by the supressor blast, found 6 to 10 feet away. The meters with no supressor stayed put but were fried. The one affected person I know did not have the surge supressors; when his line voltage went from 240 to 2400 or so all of the incadescent bulbes in the house went off like flash bulbs even though they were turned off (the switches arced over) and arcing was seen across the face of an empty receptacle that he happened to be looking at. Strangely many of the compact flourescent bulbs survived, and out of 5 computers and 2 televisions which were plugged in only one HDD and 1 video card died (both on surge supressor outlet strips, unlike some of the survivors). His damage likely would have been a lot worse if the surge supressors on other houses had not been there to help clear the transformer more quickly (all pole pigs on the circuit failed open - the 47kV line breaker did not open).

I know of another similar incident a few decades ago, caused by a tree trimming mishap rather than a storm, where there were no meter base surge supressors and several houses were burned to the ground by the near minute long overvoltage fault. 240 volt curcuit breakers cannot clear a 2400 volt fault; the contacts arc over. Blowing the meter out of the socket is a more effective disconnect since the contacts are much further apart.

Reply to
Glen Walpert

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