tool to test circuit breakers?

[JJWalecka]

Is there a tool or technique to make sure a circuit breaker is working properly?

I have the tool used to check a GFCI, to make sure it trips at the proper setting.

Some contractors have old circuit breakers stocked on their shelves. I was wondering if installing them would be a liability and or safety issue.

Justin

 

[480sparky]

Most run-of-the-mill breakers are so inexpensive, it's cheaper to just buy a new one rather than waste the time to test an old one.

 

[iwire]

http://www.google.com/products?q=ci...ent=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wf

I found some for rent, only $2,000 $3,000 per month.

 

[LarryFine]

You don't need that expensive stuff. All you need is a Variac and a clamp-on ammeter.

 

[GeorgeB]

You don't need that expensive stuff. All you need is a Variac and a clamp-on ammeter.

Rather than overload a directly connected Variac, I used to use a 6.3V 50A filament transformer between the 2. With the demise of the FETs in heated glass bottles (BIG GRIN), these are not as prevalent as they once were.

 

[zog]

Is there a tool or technique to make sure a circuit breaker is working properly?

What type of breakers? They will all require different types of test equipment, we have millions of dollors invested in CB test equipment. A primary injection test set, which is the most important piece of equipment, runs in the $20k-$50k range.

Some contractors have old circuit breakers stocked on their shelves. I was wondering if installing them would be a liability and or safety issue.

Justin

Unless they are fully tested with the proper equipment (calibrated) there is no way to know if they will work or not and can be a huge liability.

 

[Rewire]

Is there a tool or technique to make sure a circuit breaker is working properly?

I have the tool used to check a GFCI, to make sure it trips at the proper setting.

Some contractors have old circuit breakers stocked on their shelves. I was wondering if installing them would be a liability and or safety issue.

Justin

Are you talking old or used? We have breakers left over from jobs that will set on the shelf until we find a use.

 

[iwire]

What type of breakers? They will all require different types of test equipment, we have millions of dollors invested in CB test equipment. A primary injection test set, which is the most important piece of equipment, runs in the $20k-$50k range.

I bet we are talking 1, 2 and 3 pole 15 through 100 amp molded case circuit breakers used for branch circuit and small feeder protection.

Unless they are fully tested with the proper equipment (calibrated) there is no way to know if they will work or not and can be a huge liability.

From a guy that makes his living testing breakers. :grin:

 

[JJWalecka]

Iwire "I bet we are talking 1, 2 and 3 pole 15 through 100 amp molded case circuit breakers used for branch circuit and small feeder protection."

Yep

Rewire "Are you talking old or used? We have breakers left over from jobs that will set on the shelf until we find a use."

A used circuit breaker a few years old would presumably be ok? I know of a few contractors that might remove a breaker and then install it on another project.

To insure safety, I was wondering if the breaker could be tested before installation. I have never seen this done.
Seemed like a liability issue if the used breaker wasn?t tested. For that fact, how would you document that the breaker passed testing?

 

[LarryFine]

How does one really know that even a new breaker will function properly?

 

[480sparky]

How does one really know that even a new breaker will function properly?

You don't.

 

[zog]

How does one really know that even a new breaker will function properly?

You don't, which is why larger projects will require acceptance testing. The OEM's don't test every breakers, they just do batch testing.

 

[zog]

Rewire "Are you talking old or used? We have breakers left over from jobs that will set on the shelf until we find a use."

As long as they are still under waranty I don't see a problem with that.

A used circuit breaker a few years old would presumably be ok? I know of a few contractors that might remove a breaker and then install it on another project.

Yikes!

To insure safety, I was wondering if the breaker could be tested before installation. I have never seen this done.

Sure it can, there are many companies that do nothing else but testing of breakers, transformers, etc...

Seemed like a liability issue if the used breaker wasn?t tested. For that fact, how would you document that the breaker passed testing?

Yes it is, you just fill out a test report.

 

[brian john]

A small high current test set for testing CBs (20-100 amp CBs) runs around 8,000.00 and they go up from there, larger frame CBs will need to be ductored/DLRO'd another 3-4K, then a megger 300.00 and up.

Then the knowledge to utilize the equipment and understand the results.

 

[iwire]

Iwire "I bet we are talking 1, 2 and 3 pole 15 through 100 amp molded case circuit breakers used for branch circuit and small feeder protection."

Yep

In that case I do not know anyone testing these before putting them for use.

 

[JJWalecka]

Thank you for your input

 

[glene77is]

http://www.google.com/products?q=ci...ent=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wf

I found some for rent, only $2,000 $3,000 per month.

iWire,
Point well taken.

And this
/quote/ Megger DDA-1600, Universal Circuit Breaker Test Set (for
Universal Circuit Breaker Test Set (for Breakers up to 1600 Amps) 1600A, 460V 60Hz (CE) DDA-1600 Circuit Breaker Test Set /quoteEnd/
at $42,000 U.S. dollars.

 

[brian john]

How does one really know that even a new breaker will function properly?

We recently tested 6 - 225 amp CBs for a client and 4 of the 6 failed, we also just tested 480 - 250 amps CBs and all passed, different manufacture.

 

[iwire]

We recently tested 6 - 225 amp CBs for a client and 4 of the 6 failed, we also just tested 480 - 250 amps CBs and all passed, different manufacture.

Brian, just to clarify, what do you mean by failed?

• The breaker never opened?
  
• The breaker opened above stated capacity?
  
• The breaker open below stated capacity?
  
• The breaker was slower or faster than it was supposed to be?

 

[brian john]

Brian, just to clarify, what do you mean by failed?

• The breaker never opened?

• 
  
  They fell outside the published time current curves
  
  

  [*]The breaker opened above stated capacity?[

  I'd have to check the reports I was only told they failed and was questioned what to do about replacements.