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Title: Separate Breakers
Post by: Tamar Ghobria on January 30, 2014, 07:31:22 am
What is the best way to detect if two different outlets are on the same breaker? Any gadgets out there....I just bought something from Home Depot but wasn't sure if there was something out there which everyone uses
Title: Re: Separate Breakers
Post by: Chris Hindle on January 30, 2014, 08:44:37 am
What is the best way to detect if two different outlets are on the same breaker? Any gadgets out there....I just bought something from Home Depot but wasn't sure if there was something out there which everyone uses
The only <no gadget> sure-fire no question about it way is to plug a light (or something) in each outlet, and throw the breaker.
Then, either on the outlet or on a drawing of the room, write down which breaker controls which outlet.
I have used a couple different version of the "plug this thing into the outlet, and use the sniffer at the breaker box", and once I *think* I have identified the breaker, I do the light thing to verify. I am often wrong (using the sniffer only).
Depending on the distance, and how the wiring is routed before hitting the box, the sniffer is easily fooled (2 or 3 breakers all seem to be the source)
The sniffer will tell you "around here", after that, you still gotta throw a couple of breakers.
I mostly do this kind of thing in residential. For my rig, I have my own distro.
Title: Re: Separate Breakers
Post by: Tamar Ghobria on January 30, 2014, 09:01:16 am
The only <no gadget> sure-fire no question about it way is to plug a light (or something) in each outlet, and throw the breaker.
Then, either on the outlet or on a drawing of the room, write down which breaker controls which outlet.
I have used a couple different version of the "plug this thing into the outlet, and use the sniffer at the breaker box", and once I *think* I have identified the breaker, I do the light thing to verify. I am often wrong (using the sniffer only).
Depending on the distance, and how the wiring is routed before hitting the box, the sniffer is easily fooled (2 or 3 breakers all seem to be the source)
The sniffer will tell you "around here", after that, you still gotta throw a couple of breakers.
I mostly do this kind of thing in residential. For my rig, I have my own distro.


I kind of had the same experience....The device I got would beep no matter what....then sometimes not...Just didn't seem reliable..
Title: Re: Separate Breakers
Post by: frank kayser on January 30, 2014, 10:12:47 am

I kind of had the same experience....The device I got would beep no matter what....then sometimes not...Just didn't seem reliable..

Same experience. I wouldn't bet my life on one.
Title: Re: Separate Breakers
Post by: Mike Sokol on January 30, 2014, 11:02:34 am
Same experience. I wouldn't bet my life on one.

A cheap boom-box or clock radio (anything that will make a lot of noise as soon as the AC power is turned on) makes a good second helper. Plug it into the article in question and turn it up until you can hear it from the circuit breaker panel, then start flipping breakers until the sound goes on and off with your breaker flip. Then put a mark on that receptacle that matches your CB# in the panel.
Title: Re: Separate Breakers
Post by: Tamar Ghobria on January 30, 2014, 12:16:11 pm
A cheap boom-box or clock radio (anything that will make a lot of noise as soon as the AC power is turned on) makes a good second helper. Plug it into the article in question and turn it up until you can hear it from the circuit breaker panel, then start flipping breakers until the sound goes on and off with your breaker flip. Then put a mark on that receptacle that matches your CB# in the panel.

Most venuse I work in won't allow us to just start flipping breakers
Title: Re: Separate Breakers
Post by: Ray Aberle on January 30, 2014, 12:23:06 pm
What is the best way to detect if two different outlets are on the same breaker? Any gadgets out there....I just bought something from Home Depot but wasn't sure if there was something out there which everyone uses
If you're dealing with what I did, when I re-wired my house-- I had multiple things on random circuits, several overloaded, one circuit that the previous owners "fixed" by adding a GFI outlet in the living room-- that sure didn't stop the light switch from smoking, but I guess it was easier to re-set that in the LR then have to go to the service panel... Another circuit that had **19** things on it (outlets and receptacles) ending at the microwave in the kitchen (!!). So basically I ended up just chopping power, disassembling outlets/fixtures to bare wire, and my dad and I went through with a multimeter and figured out where a wire went from the service panel. It was a long, painstaking process, but helped to figure out a) what we were dealing with so we could b) figure out what we were going to do with it.

Ended up re-balancing everything on paper, and then pulled out the aluminum wiring, replaced with copper, upgraded circuit counts where needed, added AFCI breakers where required, outdoor outlets that weren't there before, -- ugh. It took a bit, but it's all amazing-like now. (Oh, and pulled Cat5/Cat3/RG6 to each room, and expanded wall outlets in bedrooms from one gang to two, cos you never have enough outlets in a bedroom, what with cell phone chargers, computers, TV and game consoles becoming more prevalent in bedrooms these days.)

So tl;dr -- if there's no power, and you had bare wires on both ends, you could use a meter to check for continuity from one wire to the other, after connecting them on the other outlet. Best to do if you're gonna rip it all out and re-do it anyways.  :D   [Probably would not suggest doing this at a venue... haha.]

-Ray
Title: Re: Separate Breakers
Post by: Jerome Malsack on January 30, 2014, 01:14:46 pm
Most venuse I work in won't allow us to just start flipping breakers

I would recommend a site visit the week before the event and before the door open to customers.

The reason why is because if you shut down the power on the Point of Sales computers,  Cash Registers. 
They can not work with the customers.  Being in before the open doors allows them time to test and to get there computers back on line. 

But one should ask why they dont have power backup systems?   
Title: Re: Separate Breakers
Post by: TJ (Tom) Cornish on January 30, 2014, 01:24:34 pm
But one should ask why they dont have power backup systems?
Due to cost, and not needing them, other than for folks turning breakers on and off.
Title: Re: Separate Breakers
Post by: TJ (Tom) Cornish on January 30, 2014, 01:29:08 pm
Most venuse I work in won't allow us to just start flipping breakers
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.

For venues that have unlabeled/inadequate power, you basically have two choices - either work with them to improve this if it's a reoccurring event - working to get either more 5-20 circuits or a 14-50 circuit installed, or downscale your show to fit the venue.  There's only so much noodling that you can do.
Title: Re: Separate Breakers
Post by: Steve M Smith 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.
Title: Re: Separate Breakers
Post by: Mike Sokol 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.
Title: Re: Separate Breakers
Post by: Steve M Smith 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.
Title: Re: Separate Breakers
Post by: Mike Sokol 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.
Title: Re: Separate Breakers
Post by: Tamar Ghobria 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
Title: Re: Separate Breakers
Post by: Mike Sokol 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...  ;)
Title: Re: Separate Breakers
Post by: Chris Hindle 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 !
Title: Re: Separate Breakers
Post by: Jonathan Johnson 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.
Title: Re: Separate Breakers
Post by: John Sabine 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.

Title: Re: Separate Breakers
Post by: Stephen Swaffer 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.
Title: Re: Separate Breakers
Post by: Jonathan Johnson on January 31, 2014, 01:18:18 am
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 used to live in a tract home, built in 2003. Code requires a 15A circuit in the garage. The inrush current of many power tools is greater than 15A... whenever I was doing woodworking in there, I often had to reset the breaker after trying to turn on a saw or air compressor or something of that nature. Most of the time it didn't overload, but many times it did. Quite annoying, when for less than a hundred bucks (on a $170,000 home) the whole problem could have been avoided by installing a 20A circuit. Rewiring it wasn't much of an option because the walls were already finished. And the crazy thing is, it wasn't wired by the cheapest electrician in town.
Title: Re: Separate Breakers
Post by: Mike Sokol on January 31, 2014, 07:12:02 am
I like Mike's pulsating load idea-might come in handy identifying which neutral wire goes to which circuit in that j-box, too.

This "Pulsar" is a pretty handy gadget to have around for troubleshooting all kinds of "current" issues including neutral current paths. I'll see if I can find a cheap source of timer-relays and build one again. Also, an analog meter is best for this type of troubleshooting, or at least a digital meter with an analog bar scale. It's really hard to read a pulsing current on a digital display that may only update a few times a second. I did this originally nearly 40 years with a Triplett analog clamp meter, and Amprobe still makes the RS-3 analog meter.   
Title: Re: Separate Breakers
Post by: Stephen Swaffer on January 31, 2014, 10:11:21 pm
The inrush current of many power tools is greater than 15A...

It is not uncommon for inrush to be 2 to 3 times FLA-so a so a half horse motor pulling 9.8 A can pull 20 to 30 amps on start up.  #14 wire has a resistance of roughly 3 ohms/1000 feet.  50 feet of NM=100 feet of wire or .3 ohms times 30 amps =9 volts drop which means the motor will start harder and pull even more amps as well as take longer to start which often equals a tripped breaker.  The 15 A breaker MIGHT have held if they had used #12.  Voltage drop is always the worst on a circuit when it is working the hardest-which is when it is most harmful-be it a power or speaker circuit.

I ran across a home built in the 90's with the range circuit wired with #12 NM, on the opposite corner of the house from the panel across an 90% finished basement.  Yes the right wire would have cost more-but nothing close to my quote to fix it-which was deemed too pricey.  Far better to plan and do it right the first time, but I find it very difficult to get owners/managers that are not familiar with electricity to stop and think about what they might or likely will do in a space in the future. 
Title: Re: Separate Breakers
Post by: Jonathan Johnson on February 02, 2014, 10:43:29 pm
This "Pulsar" is a pretty handy gadget to have around for troubleshooting all kinds of "current" issues including neutral current paths. I'll see if I can find a cheap source of timer-relays and build one again. Also, an analog meter is best for this type of troubleshooting, or at least a digital meter with an analog bar scale. It's really hard to read a pulsing current on a digital display that may only update a few times a second. I did this originally nearly 40 years with a Triplett analog clamp meter, and Amprobe still makes the RS-3 analog meter.

Such tools and tests do require the technician have the ability to interpret the results, based on what would be expected on a properly wired and functioning circuit, the expected results from different possible fault conditions, and a fair amount of intuition. There is no magic tool with a green light indicating "all OK" and a red light indicating "something's wrong." Even a basic pass/fail cable tester can falsely indicate a pass where a fault exists.
Title: Re: Separate Breakers
Post by: Mike Sokol on February 05, 2014, 10:56:38 am
Such tools and tests do require the technician have the ability to interpret the results, based on what would be expected on a properly wired and functioning circuit, the expected results from different possible fault conditions, and a fair amount of intuition. There is no magic tool with a green light indicating "all OK" and a red light indicating "something's wrong." Even a basic pass/fail cable tester can falsely indicate a pass where a fault exists.

A few years ago I started drawing circuit diagrams of how power is hooked up and distributed, just to get my mind wrapped around how to test for strange problems. Here's one that shows the basic connections. I made another diagram somewhere that includes typical series resistance you might find in the wiring so I can calculate expected voltage drops with typical loads. I'll post that one later once I find it in my archives. 
Title: Re: Separate Breakers
Post by: Frank DeWitt on February 05, 2014, 12:41:12 pm
It is interesting how wiring needs change.  I designed and built my house 25 years ago.  At the time I way over wired it.  All 20 amp #12  different circuit for each bedroom ETC.  I ran 2 ckts to each counter in the kitchen (Total 4) plus one for microwave, one for frig, and one for lights, and one for dish washer.  Now 7 is the minimum code for a kitchen.  I put only one outlet in each bathroom because why would you want more, plus power in a bathroom can be dangerous.  Last week I added two more duplex outlets to one bathroom and one more to the other.  (I didn't see electric tooth brushes or electric towel heaters cumming. 

My point,  It is quite hard to over wire a house, and now I understand why most old houses seem under wired.

BTW When I bought my first house it had one outlet in each room down stairs and one light (no outlets) in each room upstairs. All on a 30 amp service  15 down, and 15 up.
Title: Re: Separate Breakers
Post by: Jonathan Johnson on February 05, 2014, 04:49:58 pm
I designed and built my house 25 years ago.  At the time I way over wired it...  Last week I added two more duplex outlets to one bathroom and one more to the other.  (I didn't see electric tooth brushes or electric towel heaters coming.)

My point,  It is quite hard to over wire a house, and now I understand why most old houses seem under wired.

In residential wiring, code requires that no spot along a section of usable wall (the fixed portion of a sliding door counts as wall) be more than 6 feet from a receptacle. This rule is often misinterpreted that outlets can't be more than 6 feet apart, but a strict reading of the rule reveals the spacing is actually 12 feet (but limits to 6 feet from the end of the wall). The purpose of this rule is to reduce or eliminate the use of extension cords and to prevent cords running across doorways.

The spacing of outlets is probably still adequate, but only putting a duplex receptacle at each location isn't. On each side of our bed, my wife and I have power strips with several things plugged in: bedside lamp, clock radio, & cell phone charger on each side. If there was a quad receptacle (two duplex in a 2-gang box) on each side of the bed, the power strip would be unnecessary. I think that will become a new standard due to the proliferation of electronic devices: quadplex receptacles throughout the house.

On a side note, when a customer of mine is remodeling an office, I tell them to put network drops in every possible location they may need one, then double it. (Consider that each desk may have a PC, a phone, and a printer all wanting to connect to the network!) It's much cheaper to overwire when the walls are open than to add wiring later. I've had many customers who've ended up using the extra wire.
Title: Re: Separate Breakers
Post by: Jonathan Johnson on February 05, 2014, 04:55:59 pm
I ran across a home built in the 90's with the range circuit wired with #12 NM, on the opposite corner of the house from the panel across an 90% finished basement.  Yes the right wire would have cost more-but nothing close to my quote to fix it-which was deemed too pricey.  Far better to plan and do it right the first time, but I find it very difficult to get owners/managers that are not familiar with electricity to stop and think about what they might or likely will do in a space in the future.

Using too small of wire for a large load is like using a garden hose to put out a house fire. It's not going to do the job and something's going to burn.

The larger the load, the larger the wire needed; just like the larger the fire, the larger the hose you're going to need.
Title: Re: Separate Breakers
Post by: Frank DeWitt on February 05, 2014, 06:00:36 pm
If there was a quad receptacle (two duplex in a 2-gang box) on each side of the bed, the power strip would be unnecessary. I think that will become a new standard due to the proliferation of electronic devices: quadplex receptacles throughout the house.

On a side note, when a customer of mine is remodeling an office, I tell them to put network drops in every possible location they may need one, then double it. (Consider that each desk may have a PC, a phone, and a printer all wanting to connect to the network!) It's much cheaper to overwire when the walls are open than to add wiring later. I've had many customers who've ended up using the extra wire.

I saw that one coming  6 outlets om my side and 4 on my wife side and a 25 pr phone cable to the basement from one side. 

We have a rule at church  any time we pull any wire not in conduit, we pull a extra CAT 5 with it.  if we are pulling CAT5 we also pull an extra.  These days you can run anything on CAT5   data, audio, HDMI video, etc.  There is even a company that runs HDMI AND power so you can put a wide screen at the end of just a CAT5
Title: Re: Separate Breakers
Post by: Stephen Swaffer on February 05, 2014, 06:37:11 pm
Leviton makes a TR duplex that includes 2 usb charging ports and fits in a single gang box.  Not cheap-but cheaper than having an electrician add another gang-and a lot less painless if it just a "honey do: project, too!