Service Factor & Temp Rise

[George Stolz]

In the following graphic...



Since the temp rise is 40?C, and the service factor is 1.15, then I can use 125% overload protection per 430.32(A)(1).

If the service factor were 1.14 and the temp is 40?C, then I must use no greater than 115%.

If the service factor were 1.15 and the temp is 41?C, then I must use no greater than 115%.

Are all the above observations correct?

 

[Smart $]

In the following graphic...

View attachment 8509

Since the temp rise is 40?C, and the service factor is 1.15, then I can use 125% overload protection per 430.32(A)(1).

If the service factor were 1.14 and the temp is 40?C, then I must use no greater than 115%.

If the service factor were 1.15 and the temp is 41?C, then I must use no greater than 115%.

Are all the above observations correct?

Yes... but I highly doubt you will ever run across the oddball ratings

 

[George Stolz]

Just trying to be very accurate with the class.

 

[Gregg Harris]

In the following graphic...

View attachment 8509

Since the temp rise is 40?C, and the service factor is 1.15, then I can use 125% overload protection per 430.32(A)(1).

If the service factor were 1.14 and the temp is 40?C, then I must use no greater than 115%.

If the service factor were 1.15 and the temp is 41?C, then I must use no greater than 115%.

Are all the above observations correct?

I do believe that it is either or that allows 125%

 

[Smart $]

I do believe that it is either or that allows 125%

Ahh! I believe you have a point.

If service factor 1.15 or greater, up to 125%. The temperature rise doesn't matter.
If temperature rise 40?C or less, up to 125%. The service factor doesn't matter.

 

[George Stolz]

Well, which is it?

I ask because I originally thought it was "either" but we all got the question marked as wrong when we regarded it as such.

 

[Smart $]

Well, which is it?

I ask because I originally thought it was "either" but we all got the question marked as wrong when we regarded it as such.