Paul Keleher Electrical Services

Electrician, Heating and HVAC

Located in Berlin serving Berlin, Concord and Bolton areas

GIVE US A CALL: (978) 838-2457

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Circuit-Breaker Testing

Limited test data reveals that 10% of installed circuit breakers allow the branch circuit they are installed to protect from overheating, to do just that whenever a short-circuit occurs


Paul Keleher has gathered circuit breaker test data from throughout the US, gathered by professional users of the CBA-1000 Circuit Breaker Analyzer. This early data on the performance of residential circuit breakers reveals some surprising indications:

  • The circuit breaker protecting 57% of the standard 120V outlets in our homes and businesses will not clear a short-circuit instantly, but will take sometimes seconds to open
  • 10% of these delayed responses result in overheating of the wire or cable they protect when compared to the standard for acceptable short-circuit protection added to the 2011 edition of the National Electrical Code.

If your circuit breakers do not meet the requirements of this new standard, you may be in danger of having an electrical fire if a short-circuit occurs!

2004 EC&M magazine’s “Product of the year” category winner

In pursuit of a better understanding of how circuit breakers work, Paul Keleher invented, patented and with engineering assistance developed the first plug-in tester to conduct a controlled short-circuit test of a 120-volt branch circuit from an outlet, and record critical data on the installed performance of circuit breakers. He formed KO Instruments, Inc. in 2003 to commercialize the CBA-1000 Circuit Breaker Analyzer, which was recognized by EC&M Magazine as the Test Instrument of the Year in 2004.

When to Call a Pro:

Contact Us

If you think the circuit breakers in your home may be more than 10 years old or may have been subjected to moisture, Contact us to have your service examined and your circuit breakers tested. Testing your breakers is inexpensive and takes less than an hour. I will deliver a written report to you on the performance of your breakers and any hidden safety dangers that may have been revealed by the testing.

Paul Keleher