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ADP611 (Electrical) (OP)
1 Jul 11 9:09
I'm under the impression that when a contactor is to be operated in AC-4 conditions more than ten times per minute, one should select a contactor that is one size larger than if it were not operated this frequently.  I just wanted to clarify whether going the next size up was referring to the next highest current rating or the next highest frame size for an IEC contactor.  Any insight is appreciated, thanks.
ADP611 (Electrical) (OP)
1 Jul 11 9:10
Correction, ten times in ten minutes.
ScottyUK (Electrical)
1 Jul 11 15:15
Most manufacturers will list an AC-4 rating, or be able to advise you. I'd expect to go up a frame size.

The relevant standard is IEC 60947-4-1. The nearest standard class for intermittent operation is Class 120 per IEC 60947-1.

If we learn from our mistakes I'm getting a great education!

ADP611 (Electrical) (OP)
6 Jul 11 11:11
Thanks for the input ScottyUK.


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