Gerry Stebnicki
New member
when using rule 430.52 to select overcurrent protection for a motor, is it common to use exception #1 and round up to the next size or to use the calculated value and the maximum and always stay below that value.
Using rule 430.52
- Thread starter Gerry Stebnicki
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- Location
- Logan, Utah
Welcome to the forum.
The code permits us to select the next higher overcurrent protective device in accordance with Exception #1, but does not require that we do this.
This would be a design issue. I have always used an OCPD under the value I get from Table 430.52 first and then if there was a problem with the start up I would go from there.
For what it is worth I have never needed to use Exception #1 to 430.52(C).
Chris
The code permits us to select the next higher overcurrent protective device in accordance with Exception #1, but does not require that we do this.
This would be a design issue. I have always used an OCPD under the value I get from Table 430.52 first and then if there was a problem with the start up I would go from there.
For what it is worth I have never needed to use Exception #1 to 430.52(C).
Chris
shamsdebout
Senior Member
- Location
- Macon,GA
I use the MOCP from the manufacturer.
- Location
- Logan, Utah
Not all motors have a maximum overcurrent protective device marked on the nameplate or in the directions.
I agree with you if this were an A/C unit with a marked nameplate for example.
Chris
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