How is a circuit breaker rated

Measure / evaluate primary test circuit breaker / contact resistance

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Hello chimes,

maybe someone can help me?

I am supposed to carry out and evaluate contact resistance measurements on circuit breakers in the near future.
These are circuit breakers at low voltage level 400 / 690V with rated current
from 400-1000A

I want to use a MEGGER microohmmeter for the measurement.
This measuring device generates currents of up to 100A during the measurement, and is for
the contact resistance measurement is provided on circuit breakers.

Now the question is ...
1.
Where can I get information on limit values ​​/ guide values
come from? ... and regardless of manufacturer!
Surely that should be stipulated in some standard / VDE / IEC.
Unfortunately, I don't really find anything useful about this.

2.
Do I understand the word primary examination correctly?
>> Measurement of the contact resistance of the main contacts of a circuit breaker.
?? Or are there other requirements hidden behind it?



After all, I can't just use any switch that costs tens of thousands of euros
Declare an estimate dead


ps.
These are not switches in public distribution networks.
You certainly need some kind of certificate for this



Schneider88