A little electricity 101 if you please

[Larry]

Usually, but I can still work on wiring without them, :)

[Larry]

Actually, I read the OP too quickly and thought that the question was worded as "OR" rather than "AND" OTOH, if I am working on a job where I feel it is necessary to shut off the breaker, I would still use my old Ideal tester before I touched any bare wires. Especially in older houses; just too much is possible.

[Thomas Horne]

RBM wrote: > By code, it has to have at least one >

That is simply untrue. Any service can have up to six mains switches, fused pull outs, or circuit breakers. Any single panel can have two separate disconnecting means each controlling only a portion of the panel.

-- Tom Horne

[Thomas Horne]

Tom J wrote: > In these thousands of panels like mine that was installed in the '60's > and are still in production and being sold today, the breaker marked > MAIN only cuts off the 110V circuits that are below it. All the 220V > breakers above it and the buss for them is still hot when the MAIN > breaker is off. None of the 220 breakers say MAIN, and even if they > did, the buss bars are still hot. People that don't understand how > panels are wired really need to get an electrician when it comes time > to add things to the service panel. >

Those are not still sold in the US because the US code now requires lighting and appliance panel boards to have no more than two disconnecting means.

-- Tom Horne

[Tom J]

Really, they are not sold anymore? I don't think the installer stole the one that was just installed last week??

Tom J

[Thomas Horne]

All right I'll play your game. What is the manufacturer and the model number?

-- Tom Horne

[John R]

Of course, anyone can (and does) AT ALL TIMES distinguish between "knowing the breaker is off" and "thinking the breaker is off, but it isn't".

[Bob]

I have no definitive answer. What is (or was) the price difference between a 50 amp and 100 amp double pole breaker? If the latter is substantially more, that can potentially justify using a split bus panel.

[Charles Bishop]

I wouldn't. Is the voltage due to the resistance of the dimmer? You don't see voltage between the terminals of a regular switch do you?

Interesting. I'll check next time I get a chance.

[Chris Friesen]

In Canada, "normal" installation for kitchen counter circuits is to use shared-neutral 15A circuits.

Chris

[Doug Miller]

Ummmm.... "one" is included in "up to six". RBM's point was that "none" is not an option permitted by Code.

[Doug Miller]

Hence the large number of responses, mine included, advising the OP to test first anyway. The point remains that it is not possible to get a shock from a circuit that is not energized -- which is what the OP asked about.

[Doug Miller]

Then you should alter your expectations to conform to reality. :-)

No, the light bulb(s), as I noted.

Yes -- you should try it some time.

Do that.

[Doug Miller]

Quite so -- but, as I understand it, that's not the norm *except* in kitchens. And it's certainly not the norm in the US, kitchens or otherwise.

[Herb and Eneva]

Re phone lines=---It is very possable for a phone line to have enough current to get a good shock. Telephone lines have a standing voltage of 48vdc and super impossed ac of up to 100 v. for ringing but very low amps. So if you are working on a phone line and ringing currant comes across that line you would feel it. It could startle you and make you fall off of a ladder etc. Allways be careful.

[Puddin' Man]

Not exactly the response I expected.

Comprendere, senor.

And if one manually opens the main, barring a fault of a certain kind and/or a main breaker failure, one can expect that there is -no- power anywhere in the house (given a simple, single svc. panel application)?

And it can take (at least figuratively) 40 days and 40 nites to precisely figure out what's what in the circuitry? :-)

Your honesty is appreciated.

I'll assume split buss (residential) prevalence has *something* to do with "The Industry" until I have evidence to the contrary.

Thanks, Puddin'

"Life is nothing but a competition to be the criminal rather than the victim." - Bertrand Russell

[Barney]

Phone circuit has approx 50 volts DC idle and approx 80 volts AC ring voltage. will cause curse words to come out of your mouth or worse if you have a bad ticker.

[Goedjn]

If there are two hots, the chances are they're opposite polarity. Otherwise, why would there be two of them?

[Goedjn]

Well... Absent broadcast power, big static charges, and huge motors winding downs....

[Bud--]

Re "MAIN" - all service disconnects are required to be marked.

I looked that up earlier in the thread - NEC 408.36-A. What is the intent of "2"? Seems like that allows continued installation of the old "main and range" fuse panels with 2 60A pullouts, one for the plug fuses (or equivalent CB panels).

[Exception #2 specifically grandfathers old split bus service panels.]

-- bud--