×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Circuit Breaker Finder

Circuit Breaker Finder

Circuit Breaker Finder

(OP)
I have a Data Center where I cannot turn power off but I need to find out which PDU uses which 30 amps breaker.

I recent purchased a "circuit breaker finder" tool to help me find this out. But when I use this tool it points me that there are atleast 4 of my PDU's using the same breaker. But this is not possible becuase I know for the fact that these PDU's totally draw over 45AMPS. So it is not possible that all 4 of them are using the same breaker.

How do I find out which breakers are used for all these PDUs?

RE: Circuit Breaker Finder

What product are you using?  They are not all created equal.  

And where are you located?

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

RE: Circuit Breaker Finder

(OP)
I am located in NJ. I was using the "IDEA 61-532" to do my testing

RE: Circuit Breaker Finder

http://www.aemc.com/products/pdf/2115.49.pdf

These seem to work.  

I'm not sure about the Idea unit you reference.  If there are a lot of harmonics that could effect the accuracy of the circuit tracer.

 

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

RE: Circuit Breaker Finder

(OP)
Thanks for the link. But when I took the same circuit breaker tester home it worked perfectly all right.

What does this mean? Could it be a bad wiring in my data center that leaks all around and shows maximum signal on a certain breaker instead of it's own breaker.

It won't be a good idea to buy another tool which will give me the same results since the problem is somewhere else.

Any more info on this appreciated.

RE: Circuit Breaker Finder

Well you have to consider the complexity and current density is an order of magnitude or so greater than a typical home, with very levels of harmonic distortion and neutral triplen harmonics, not to mention the radiated RFI that could be causing interference with a low-end product.  

Where else would the problem be?  

Call an electric supply house and ask them what they sell the most of to working electricians.

Also, how do you know what the actual current draw is on the PDU?   

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

RE: Circuit Breaker Finder

The unit is an ideaL not an idea.
Do you get any indications on other breakers?
Are these single pole breakers, two pole breakers or three pole breakers?
Are the PDUs single phase or three phase?
What voltage are the PDUs?
After you buy a clamp on ammeter, you can find your circuits by plugging in a 100 Watt or 150 Watt lamp along with a PDU.
Have someone turn the lamp on and off and check your wires at the breakers with the ammeter.
If this test shows more than one breaker, call a GOOD electrician or a GOOD engineer and be ready for a badly needed shutdown.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Circuit Breaker Finder

(OP)
Well you have to consider the complexity and current density is an order of magnitude or so greater than a typical home, with very levels of harmonic distortion and neutral triplen harmonics, not to mention the radiated RFI that could be causing interference with a low-end product.  

Where else would the problem be?  

Call an electric supply house and ask them what they sell the most of to working electricians.

Also, how do you know what the actual current draw is on the PDU?    

I have no clue about what harmonic distortion, radiated RFI or neutral triplen harmonics mean. I will read all that up as soon as I get some chance. If I have to call an electrician I would do so; but that is exactly what I am trying to find out first. Is the power circuit and wiring bad or is it just my tester not so good?

My PDU's have a digital display of the current draw.  

RE: Circuit Breaker Finder

(OP)



That was my bad on type. Yes the tester is indeed IDEAL not IDEA.

With the tool it indicates that several PDUs on the same breaker which is not possible since the breaker is only 20amps, if I add up all the PDU's current draw it would be more than 60amps.

Not sure what it means by single pole breakers or two pole breakers. But I can tell that there are 2 columns of breakers. Each column has around 6-7 breakers.

Not sure if the PDUs are single phase or three phase.

The PDU's are 110V

As per the tool it does show the same breaker for multiple pdu's which is not possible. The question is, 1) is it bad wiring and I need an electrician to fix it? or 2) the tool that I have is not doing such a good job?

RE: Circuit Breaker Finder

If the tool shows that a PDU is connected to more than one breaker then there may be wiring issues and/or the tool may have issues.
If the tool shows more than one PDU connected to only one breaker that is probably the case.
Your questions indicate that you do not have the background or knowledge to undertake this type of testing.
Please, for both safety and accuracy, hire someone knowledgeable.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Circuit Breaker Finder

I like the pacer tracer by amprobe.  I also use the scotch trak by 3m.  
The quality of the tracer is important in situations such as yours.  
Most tracers have an adjustment on the receiver so that you can turn the setting down as low as possible to ensure that the only signal that gives a positive indication is your ciruit.
The better models will give audible and visual indication progressively as you get closer to your circuit.
In the not so long ago past we would install a fixed resistive load of anywhere between 2-6 amps.  We would connect the load via a flasher (used to but them in the hardware store, the kind that screw into a lamp socket).
Good Luck.  
Then we would find the circuit pulsing the current and presto you have your circuit.
You could probably make a resistive flasher for under twenty bucks.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources