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Author Topic: Separate Breakers  (Read 2132 times)

Steve M Smith

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Re: Separate Breakers
« Reply #10 on: January 30, 2014, 01:55:22 pm »

Most venuse I work in won't allow us to just start flipping breakers

Then don't ask first!


Steve.
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Mike Sokol

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Re: Separate Breakers
« Reply #11 on: January 30, 2014, 02:13:58 pm »

The only sure way to tell if two receptacles are on different circuits is to plug an extension cord into one, carry the female end of the cord over to another receptacle, and using a volt-meter, measure hot from the extension cord to hot on the other receptacle on the wall.  If you read 208 or 240 volts, they are definitely on different circuits.  If you read 0 volts, they may or may not be on the same circuit, as they are on the same phase.  BTW, if you read 120V doing this, something is wrong - there is a hot/neutral swap somewhere.

Once upon a time, in a land far away (not really, but a good opener) I built a 10-amp pulsing load from a pair of time-delay relays and a coffee pot. Since it pulsed about once per second, I was able to easily trace where that special "pulsed" current was going right in the middle of stationary loads using nothing more than an analog clamp ammeter. So, if you could get inside the panel with a clamp-meter on each circuit breaker, then plug the pulsing load into each outlet, you could easily determine if that breaker was feeding that particular outlet. Nothing needs to be shut down, and this would be 100% accurate.

If you can't get inside the live box (don't do it unless you're qualified and take proper Arc Flash precautions) you could do a secondary (but not 100% accurate test) by simply applying the pulsing load to a single outlet, then checking all other outlets for a pulsing voltage drop. I don't consider this to be 100% accurate since there could be some voltage drop in the sub-panel reflected to all other branch circuits. But I think with a little interpretation you could easily figure it out measuring the pulsing voltage drop in the various outlets.

Steve M Smith

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Re: Separate Breakers
« Reply #12 on: January 30, 2014, 02:16:17 pm »

I built a 10-amp pulsing load from a pair of time-delay relays and a coffee pot.

That is an excellent idea.

Obviously, as I'm English, I would have to do it with an electric kettle to make tea!


Steve.
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Mike Sokol

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Re: Separate Breakers
« Reply #13 on: January 30, 2014, 02:24:15 pm »

Obviously, as I'm English, I would have to do it with an electric kettle to make tea!

My wife has a British electric kettle and loves it. However, she won't let me take it to a job site. I'm thinking an electric space heater with a 600/1200 watt heat setting would give you 5 or 10 amp loads. The pulsing circuit is actually very simple if you have any time-delay relays laying around.
« Last Edit: January 30, 2014, 03:21:03 pm by Mike Sokol »
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Tamar Ghobria

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Re: Separate Breakers
« Reply #14 on: January 30, 2014, 03:32:58 pm »

My wife has a British electric kettle and loves it. However, she won't let me take it to a job site. I'm thinking an electric space heater with a 600/1200 watt heat setting would give you 5 or 10 amp loads. The pulsing circuit is actually very simple if you have any time-delay relays laying around.

I was just hoping for a simple tester that says "your screwed get a generator" or "we are all separate don't worry"....I didn't know I have to buy a coffee pot now...I will see if the client will pay for it...thanks alot
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Mike Sokol

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Re: Separate Breakers
« Reply #15 on: January 30, 2014, 03:58:38 pm »

I was just hoping for a simple tester that says "your screwed get a generator" or "we are all separate don't worry"....I didn't know I have to buy a coffee pot now...I will see if the client will pay for it...thanks alot

I just ain't that simple, sorry...  ;)

Chris Hindle

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Re: Separate Breakers
« Reply #16 on: January 30, 2014, 04:36:54 pm »

I was just hoping for a simple tester that says "your screwed get a generator" or "we are all separate don't worry"....I didn't know I have to buy a coffee pot now...I will see if the client will pay for it...thanks alot

Good one... That's the tool we all wanted, the day before deciding to build a distro !
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Jonathan Johnson

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Re: Separate Breakers
« Reply #17 on: January 30, 2014, 05:48:23 pm »

In many venues that were not designed with dedicated power for sound systems, it's common for all of the receptacles in a room to be on one (or maybe two) circuits. That's because they are installed with just one purpose in mind: a place to plug in the vacuum cleaner, and there needs to be just enough so the janitor can move about the room without using an extension cord.

Commercial building designers often forget to consider occupant use when planning the electrical. That means that the electrical isn't planned; rather, the electricians install the minimum required by code. Which is to support vacuum cleaners and building maintenance.

At least that's the way it is in the gymnasium of a school that I often work in. It's troublesome, because they like to have catered events there, which means that they want to connect coffee pots and portable lighting in addition to the sound system.
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John Sabine

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Re: Separate Breakers
« Reply #18 on: January 30, 2014, 05:57:38 pm »

This has worked pretty well for me.

http://www.ebay.com/itm/Meterman-ECB50-Circuit-Breaker-Finder-AC-Cable-Tracer-/110676860648?pt=US_Measuring_Layout_Tools&hash=item19c4dadee8

Might still be a couple of breakers to flip to narrow it down but it at least has always narrowed it down to a couple of circuits for me.

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Stephen Swaffer

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Re: Separate Breakers
« Reply #19 on: January 30, 2014, 08:49:33 pm »

Commercial building designers often forget to consider occupant use when planning the electrical. That means that the electrical isn't planned; rather, the electricians install the minimum required by code. Which is to support vacuum cleaners and building maintenance.


Another pet peeve-being asked to bid a job "wired to code".  No ones gonna be happy with it-but if I bid it wired like it should be, I ain't gonna wire it.... design/build + competitive bidding makes life rough for sound providers.

I like Mike's pulsating load idea-might come in handy identifying which neutral wire goes to which circuit in that j-box, too.
« Last Edit: January 30, 2014, 09:09:38 pm by Stephen Swaffer »
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Steve Swaffer
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