Posts Tagged ‘overcurrent test’

May 21st, 2009 Comments off

A question asked by one of our customers:


You guys work on circuit breakers all the time.  I have a used circuit breaker.  I don’t know why it was laying around in the shop, but I checked it with a VOM and operated it.  Checks okay and sounds okay.  Is it okay, or is there more to it?  My breaker is a 3 pole 100 amp plastic type circuit breaker.




Yes, there is more to it.  MIDWEST’s tests are (1) Voltage Related, (2) Current Related, and (3) Mechanical Related.  The most serious deficiencies may be current, ie heat, related.  MIDWEST overcurrent tests used and new circuit breakers.  In addition to testing the overcurrent functions and insulation quality, we also test the condition of the contacts, including contact resistance.  Poor breaker contacts can cause overheating and lead to serious damage.