Multiple power strips daisy-chained, code?

quire

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Not all adaptors are UL listed. Some jurisdictions don't care if non-UL electrical devices are used. Others go so far as to ban all but one type power adaptor. Some jurisdictions - ie colleges - completely ban extension cords. Depends upon which jurisdictions apply to your question.

In my office I have a string of THREE power strips; when I plug my space heater into the third one, all the computers shut down when the breaker on the first strip pops. ;-)

Then again, the closest thing to a fire inspector I've seen at this factory is the guy that comes and recharges the fire extinguishers. ;-)

Cheers! Rich

Because those guys (the other responders) are idiots? ;-p

Cheers! Rich

Why is daisy chaining power strips any worse than daisy chaining outlets in wall-mounted boxes? At least the power strips each have their own breakers!

There can be plenty of legitimate debate about how safe is "safe enough" though... and whether or not "safety inspectors" are actually enforcing required laws vs. just figuring they should prohibit anything that the laws don't specifically address or they don't understand.

If you need a bunch of outlets more than a few feet away from the wall receptacle it's no longer so easy. Or even safer -- having, say, six 6' extension cords run over to some equipment is often worse than a single 6' power strip with six outlets connecting equipment with relatively short cords.

---Joel

I've been known to plug in two wall warts by using one of those "ground cheater" things (the two-to-three prong adapter that we all use to float the scope ;-) ) just to extend the outlet so the second wart kind of overlaps the first, as if it's humping it. ;-D

Cheers! Rich

So you don't have to go all the way downstairs to reset the breaker. ;-)

Cheers! Rich

Oh geez. Is the cord that plugs into a regular PC power supply an extension cord? After all, it has "standard" connectors at both ends (I'm thinking the IEC-style line cords here), and it's readily available anywhere from about 2' to 15' (with 6' seemingly the most common)...

In such places I suspect a few of the EE students make a bit of beer money retrofitting long line cords into stereos, fans, TVs, etc...

If the admin can't get this clarified I will. But one has to be careful not to rock the boat too much because if he says the water runs up the drain then the water does run up the drain. But it was said he's a very friendly guy.

Oh, I will :-)

Why not use a 'cube tap' on the main outlet? Then plug in both strips to the 'cube tap' (a cube tap is a single to three adapater).

Ah, that assumes that that cheap Chinese breaker actually trips, at any current!

I think the solution is to use a 'cube tap' on the main outlet, but I don't know if Joerg can do that in his application. Another choice might be to get a 'super' strip with more outlets, and better spacing.

That's exactly what I don't understand either.

Even if they don't, if they are rated for the current what's the problem?

That's what I was told after moving to the US and wanting to install UL-rated 240V outlets in the kitchen. "If the inspector has never seen those before then he'll probably flag that as a violation"

And that is precisely the situation. Audio both, wooden structure riding on the carpet, something where I definitely would not feel comfortable hooking it up to mains permanently. And I am pretty sure the electrician won't do it either.

in

kers!

Even wall mounted boxes are limited to how many receptacles are permitted on each circuit. Then safety backup protection is a circuit breaker. And then the amount of moving and exposed wire is less.

I did not write this stuff. Generations of experience are why the circuit breaker alone is not sufficient protection. Further protection includes other requirements such as limiting the number of plugs on each circuit breaker.

However, as others here have demonstrated: which house is the one that always needs painting? The professional painter's house.

If you also need surge protection, well, the effective surge protector makes a short (ie 'less than 10 foot') connection to earth. That power strip protector does not even claim to protect adjacent appliances. In fact, it may even contribute to appliance damage. Protection is about earthing. If another wall receptacle is to be installed (as some state fire codes would require), then you should also have the breaker box earthing upgraded so that one 'whole house' protector protects everything. If protection is needed, then everything - even the church furnace - may also need that protection. Better is to install one =91whole house=92 protector that actually does provide protection.

UL says they aren't supposed to be mounted anywhere. From the UL "White Book": "Relocatable power taps are not intended to be permanently secured to building structures, tables, work benches or similar structures ...."

Then mounting hardware is a bit strange.

Exact same reasoning said it was safe to launch Challenger because backup O rings always stopped failure.

Exact same reasoning said rolling through stop signs is always safe because no one has been killed - yet.

The circuit breaker is only an emergency safety backup device. When it trips, the human is expected to fix the problem - permenantly. Rich Grise is doing a classic "second O ring is good enough" - and calls that acceptable for everyone.

Same mentality caused a local dog kennel to smoke or fry 20 some dogs because power strips were daisy chained. They also assumed a circuit breaker made it safe.

I heard that those are really, really frowned upon by inspectors. Even back in Germany they'd flag those immediately. Over there the rules are a bit more precise and none of this local stuff but cube taps were a big no-no. Main reason is that they exert too much torque onto the outlet when multiple cables are connected. Their method of outlets mounting is, ahem, hokey at best (side clamps).

Also, I've had one here that began to make bzzzzzzt noises. Then a faint ozone smell, followed by a molten-plastic stench. Didn't know what that was, turned the light off, saw faint blue arcs in a corner. Aha! Opened the cube tap and they had riveted the brass strips together. Sure enough one of those rivets let go.

Crawled under the table again and looked. Sure enough, four mounting locations on the back. Like usual. It's UL listed.

I use a couple of Tripplite Isobars with remote on-off switches inside equipment racks. The remote switch is mounted on the side of the rack and the bars are mounted inside, using their built-in mounting hardware. Our corporate safety rep passed it--though he had to go away and think about it first. Of course, it had been there for 10 years already, and the previous guy forbade us to plug it into anything except a turret box.

Cheers,

Phil Hobbs

My understanding: The NEC (published by the NFPA) has no intrinsic authority. It has to be adopted by a governmental unit (and is widely adopted, sometimes with modifications).

The NEC generally requires wiring installed to be "approved". Approval is by the "authority having jurisdiction", the inspector or governmental unit. They would normally use listing by UL (or maybe another nationally recognized testing laboratory).

Once the wiring is installed, OSHA would want equipment that is plugged in to be UL listed (or equivalent). That should include a church. OSHA would not cover a home. Fire (and other codes) could also further restrict electrical requirements.

Maybe Joerg should threaten the fire inspector with a "higher authority".

I don't think it's quite such an "emergency" safety device -- people plugging in, e.g., a 1500W space heater on a circuit that already has, say, 500W worth of computers and laser printers attached to it is a very foreseeable, common event, so the protection of wiring under such circumstances should not be viewed as "emergency" services.

The usual "permanent" fix for popping breakers is of course to just move a load to a different branch circuit, but in places like rentals I suspect that over various tenants the breakers get quite a workout. :-)

"Same mentality caused a local dog kennel to smoke or fry 20 some dogs because power strips were daisy chained. They also assumed a circuit breaker made it safe."

Do you have the details of what actually started the fire? After all, you can certainly start fires with a dozen wall-mounted outlets just as readily as you can with a dozen power strips.