location of required OCP for terminals

[Etek]

Hi there,
I'm new here and only recently deal with the topic of UL508A and SCCR calculation. I have a question that I cannot answer myself:
In a branch circuit I use terminals that only achieve an SCCR value of 100kA in related to a Class J 200A fuse. Does this fuse have to be used as branch protection or can it also be located in the Feeder circuit (Main Fuse)?

Greetings from Germany

 

[xptpcrewx]

I am not too sure what you're asking, but fuses can be used for both branch and feeder protection provided they are properly applied within their interrupting ratings.

 

[Jraef]

The fuses can be external, but your panel must include a permanent sign on the outside stating that for this panel to have the SCCR you designate, it must be fed with those SPECIFIC fuses and that not doing so reverts the SCCR to 5kA.

SB5.1.2 An industrial control panel marked with a high fault short circuit current rating and is not provided
with the required branch circuit protective device as specified in the Exception to SB4.2.3 shall be marked
with the type and size of branch circuit protection required to be installed in the field. This marking shall
be included as part of the marking in SB5.1.1.

 

[petersonra]

The fuses can be external, but your panel must include a permanent sign on the outside stating that for this panel to have the SCCR you designate, it must be fed with those SPECIFIC fuses and that not doing so reverts the SCCR to 5kA.

Where is it say anything about having a sign that says it reverts. I don't recall that being a requirement

 

[EC Dan]

I think he's asking if the fuse specified as part of a tested combination can be shared across multiple branches to satisfy multiple tested combination requirements. I would think that yes, if the fuse size specified in the tested combination rating is sufficient, but I'd be surprised if you'd get much mileage out of that strategy since the fuse size specified is likely to be sized for the protected equipment.

 

[petersonra]

I wonder whether he's using the terminals for. Short circuit current rating is not required for control circuit terminals or for terminals on the load side of a VFD.

 

[Etek]

Thank you for your answers.
I use the terminals within a branch circuit (field terminals of a motor circuit).
The branch circuit protection corresponds to a type F (manual self-protected combination motor controller + separate motor controller). I need a SCCR of 30kA for the panel.
However, the terminals only have an SCCR of 100kA related to a Class J 200A fuse.
Do I have to set up the branch circuit to type A or is it sufficient to limit the main fuse of the control cabinet to 200A?