MOLDED case breaker commissioning 1

[WiringBoy]

Hello All,
I asked a consultant to do a arc flash study on a 1600 A 120/208 switchboard. Unit has molded case circuit breakers with
Schneider Micrologic 6.0 P trip unit. i need some input in testing these breakers for commissioning using primary injection.

I will not be testing it myself but just curious if I pick some two test points on long time curve for field crew to test, how would the heating of 1st test point impact the results/timings of second point on the curve.

Any tips to address this issue.

 

[Ceast]

Step one download the manual for your breaker & trip unit. Step 2 read the attached.

http://products.schneider-electric.us/support/technical-library/?event=category&cat=0b008926800b63f0

 

[Zogzog]

Most common mistake testing companies make when testing MCCB's is the test set up itself, per NEMA AB-4 the cables should be no less than 4 feet long (They act as a heat sink). Also tests on adjacent poles should be made at no less than five minute intervals. For circuit breakers with thermal trip elements, wait at least 20 minutes before repeating tests on the same pole. For circuit breakers with electronic trip elements, consult the manufacturer’s published instructions for required intervals between tests.

You don't pick random test points, NEMA, NETA, and ANSI have standard test values for each function. Your best bet is to just check the qualifications of the testing company and make sure if they quoted primary injection they do primary injection, if they try and just do secondary injection tests call them out on it.

 

[dpmac]

You will want to insure you read the Schneider instructions that are specific to your exact equipment. In addition, you (or your testing company) will need the correct Schneider Full Function Secondary Test Set to use in conjunction with the Primary injection test set to turn off thermal memory, defeat ground fault, etc while performing primary injection testing on the 6.0 trip units. Schneider is very proud of this little Magic Box and charges accordingly.