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rizza_gay
March 18, 2016, 08:17 PM
Good Day!

What is the criteria/passing range and standards for the Contact Resistance Test of Low Voltage Air-Circuit Breaker?

Specs:
ABB Manufactured with Iu=1600A, Ue=690V , 3 phase.....

Among the 4 units I tested for its contact resistance, 3 of it has a higher values. Injected current is 100A AC.
ACB #1 : 1435 micro ohms ; 1331 ; 847.7
ACB #2 : 269.6 ; 790 ; 670.8
ACB #3 : 22.8 ; 22.4 ; 22.3
ACB #4 : 40.0 ; 39.6 ; 36.5

Note that all ACB were at the same specs....


Thank you.

Godbless.

Regards,
Rizza
Sanjayo
March 19, 2016, 03:42 AM
Greetings Rizza! All three pases should be within 50% of the lowest value.

Example: 22.3 being lowest value, contacts should not be higher than 33.45 (22.3 x 1.5).
dnigra
March 20, 2016, 06:12 PM
at 100 amps...i would give those first two a good cleaning..should drop significantly
rizza_gay
March 20, 2016, 11:36 PM
Thanks a lot. . .

Is that from NETA standard?

Regards,
Rizza
Sanjayo
March 21, 2016, 04:37 AM
Yes, the +/- 50% rule comes from NETA. Are these new breakers?


Thanks a lot. . .

Is that from NETA standard?

Regards,
Rizza
rizza_gay
March 21, 2016, 08:50 PM
Thanks a lot. . .

Is that from NETA standard?

Regards,
Rizza


Yes...those were new ACB. . .
rizza_gay
March 27, 2016, 07:11 PM
Yes, the +/- 50% rule comes from NETA. Are these new breakers?

Yup...All breakers were new. One thing I've noticed is that the breakers were in Open Position before I conducted the test. Maybe, the presence of dusts in its contact matters.
Sanjayo
March 27, 2016, 07:36 PM
What kind of instrument are you using to measure?
rizza_gay
March 27, 2016, 08:06 PM
What kind of instrument are you using to measure?

Its the DV Power CAT66 : Circuit Breaker Analyzer
Sanjayo
March 27, 2016, 08:19 PM
Its the DV Power CAT66 : Circuit Breaker Analyzer

Did you say this was 100A ac? Using Dc current would give more stable reading.
rizza_gay
March 30, 2016, 03:44 AM
Did you say this was 100A ac? Using Dc current would give more stable reading.

Yeah..100A AC


By the way sir Sanjayo...do you have any idea about the ripple test of the OLTC of Auto-Transformer?
Sanjayo
March 31, 2016, 02:26 PM
Sorry rizza, I'm not familiar with the ripple test. Did the circuit breaker readings ever improve?