SCCR documentation
- Thread starter MBLES
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packersparky
Senior Member
- Location
- Wisconsin
- Occupation
- Inspector
Almost all electrical equipment will come with and SCCR rating. The manufacturer designates the SCCR rating through a testing process, we cannot give the equipment a rating. The AIC ratings of an overcurrent device are different from the SCCRs rating of the equipment.
SCCR- the rating of the available fault current that the equipment (disconnects, RTU's, panelboard enclosures, etc.) can withstand.
AIC- the rating of the available fault current that an overcurrent device can withstand.
- Location
- Illinois
- Occupation
- retired electrician
This is an example of the CMP not really understanding the terms they are using in the code rule. The SCCR is a function of the equipment itself and that number can only be provided by the manufacturer. It is not a number that can be field calculated.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Did you mean 702.4? Or is there something different in 702.5 in the 2017 code? All it says in 702.4 (2014) is that transfer equipment shall be suitable for the Short Circuit Current available in the system, so yes, that means the SCCR. As mentioned, YOU cannot label anything. It is either labeled by the manufacturer, or it is not. If not, then you can't meet the requirement.
There are however, as I have discovered in trying to integrate ATSs into MCCs, some challenges specific to UL 1008 listed ATSs in that the labeling they have under UL 1008 is kind of different from what you get with other equipment. They are allowed to make very specific and often confusing "qualifications" to their SCCR labeling, depending on the voltage, breaker or fuse feeding it, etc. So instead of just having a label that says "Suitable for use on a circuit having a Short Circuit Current of no more than xx kA", it can be a chart that you have to relate to how it is installed and what protective devices are ahead of it. That is, unless the SCPD is PART of the ATS assembly, in which case it's simpler to apply.
There are however, as I have discovered in trying to integrate ATSs into MCCs, some challenges specific to UL 1008 listed ATSs in that the labeling they have under UL 1008 is kind of different from what you get with other equipment. They are allowed to make very specific and often confusing "qualifications" to their SCCR labeling, depending on the voltage, breaker or fuse feeding it, etc. So instead of just having a label that says "Suitable for use on a circuit having a Short Circuit Current of no more than xx kA", it can be a chart that you have to relate to how it is installed and what protective devices are ahead of it. That is, unless the SCPD is PART of the ATS assembly, in which case it's simpler to apply.
I know the equipment has the SCCR labeled inside equipment or exterior But Im asking if it needs to be posted on exterior like it mentions in 702.5 that it needs to be exterior. I have seen transfer equipment without any marking on exterior or interior. They only have literature in booklet inside equipment
I am reading 2017 code and 702.5 page 70-590 top right page highlight where it says exterior of the equipment. I understand that we dont our own calc on the spot my question is do we posted the SCCR on exterior like the we do AFC or any other label. I assume they want it posted so the guy servicing doesnt need to open the equipment and ready documentation while energized. Thanks for replies
- Location
- Illinois
- Occupation
- retired electrician
This was new text for the 2017 code.
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