What is the industrial SCCR ratings?

[LostPatrol]

Hello all,

We're an OEM and is trying to find out what number to put on the nameplate for the SCCR ratings.

Is there an industrial standards for SCCR # is?

Thanks,

 

[ryan_618]

Are you refering to short circuit current ratings?

 

[LostPatrol]

yes, the SCCR. Is there an industrial standards number?

TIA!

 

[msb10]

There is a method in UL 508A for assigning an SCCR to an industrial control panel. It is in supplement SB.

Hope this helps.

Matt

 

[petersonra]

Some companies seem to have decided to use a much smaller number than the calculations would seem to indicate. I think that if you use all listed components, there is no way to come up with a smaller number so they use that number on all their panels so they don't have to calculate it seperately each time. The number 10kA comes to mind.

 

[jim dungar]

Bob,

5K is more of a typical level as that is the "uncalculated" value for motor controllers up to 50HP (UL508A Tabel SB4.1).

 

[LostPatrol]

Those tables only tell you what your current SCCR is.

What I'm looking for is is there a SCCR number that the industry uses? I've heard some company has 50kA.

 

[jim dungar]

A) You put a label on your equipment based on what SCA it can handle, then it is up to your customer to only provide that amount.

or

B) You design your equipment to a particular level of SCA (there is no standard) but then it is still up to your customer to only provide that amount.

There are no "general" standard fault levels for industrial equipment. some equipment manufacturer groups may have standard levels (like circuit breakers at 14, 18, 22, 25, 42, 65K or motor control centers at 42, 50, 65, 100K). There may even be some industries that ask for levels (like residential loadcenters at 10, 22K).

But in general most control panel OEMS follow method A.