Standard low-voltage circuit breakers

[tavuvi]

Hello everyone.
Currently, I am testing ACB including items of insulation resistance and contact resistance.
I don't know the standard for low voltage circuit breaker.
Help me please. thank you

[Kalbi_Rob]

Hello everyone.
Currently, I am testing ACB including items of insulation resistance and contact resistance.
I don't know the standard for low voltage circuit breaker.
Help me please. thank you

NEMA AB4 GUIDELINES FOR INSPECTION AND PREVENTIVE MAINTENANCE OF MOLDED CASE CIRCUIT BREAKERS USED IN COMMERCIAL AND INDUSTRIAL APPLICATIONS

is the standard for testing LV Circuit Breakers using Primary Injection. Just be wary of voltage drop as it can only be done with a specific DC voltage, so DLRO is the preferred method. There were a few articles in NETA World discussing why voltage drop is highly unreliable.

[AaronCBI]

NETA Maintenance Testing Standards (2019 Edition) give the insulation resistance values in Table 100.1
For equipment rated at:
250V: Test At 500 VDC and minimum resistance value is 25 megaohms.
600V: Test at 1000 VDC and minimum resistance value is 100 megaohms.

This is in absence of manufacturer data, and there are tables to compensate for humidity and temperature.

[SecondGen]

Hello everyone.
Currently, I am testing ACB including items of insulation resistance and contact resistance.
I don't know the standard for low voltage circuit breaker.
Help me please. thank you

We usually do a 10A DLRO for contact-resistance, tolerance is +/-50% between phases. I've heard that some manufacturers will only recognize 100A test for warranty purposes.