SCCR
Looking for others interesting in discussing SCCR, installation, upgrades, and mitigation.

I just had a project where I had to deal with an insufficient SCCR rating on a chiller with 2 circuits.

Although the chiller panel had (2) internal breakers, each rated 65KAIC, the control panel was set up for a single point of connection and only had a 10KA SCCR rating The solution was to feed each circuit separately. The feeder cost was the same since we still needed 2 sets of conductors, but it did add an additional upstream 400A breaker to the project.

Now I would bet my last dollar that the panel would withstand a much higher fault, but my understanding is that the manufacturer has to go with a 10KA rating unless they pay UL to test it at a higher level. Because of the large number of compressor/ breaker combinations available, testing each combination would be very costly so most, if not all manufacturers opt not to do it.

The surprising thing to me was that when I discussed this with the manufacturer, I got the impression that they had never been asked this question before. Yet I don’t know where I could ever find a distribution system that could deliver 800A at 480V, with less than 10KA available.

What you said about manufacture. We had manufacture say the same thing. HUH, What? you are the only one that has ever asked...
We had a homemade (local shop vendor) built panel, The vendor never had anyone ask about SCCR before. He was in this business for 20years.
I also had a large compressor manufacture for air dryer tell our company the same thing.
Our company is pushing hard for engineers and contractor to help us comply. Some of this will rest on our company to provide guidance and references to available fault current from our engineering study(arc Flash)

Oh come on. SCCR is easy and required for industrial control panels coming from UL panel shops listed under 809A. If you actually take the time to read the standard, it is essentially almost a "mini NEC". The internal ampacity requirements are based on a 60 degree temperature rating. So just "calculate" SCCR in the panel based on a 60 degree temperature rating. Most of the time I see control panels come in now where the feed connects directly to either a breaker or fuse so that it gets even easier...SCCR specifications for the panel match the fuse/breaker rating.

I'll make you a deal - I'll will actually take the time to read 809A, if you'll take the time to read to read NEC 409.22.

I don't know why I keep screwing up my numbers. I mean UL 508A.

I've read it. I've also seen first hand results of violations, like breakers NOT tripping. The history on this is more than just the 2011 Code change where the new requirement is that industrial control panels cannot be installed where the SCCR exceeds the panel's rating. That's identical to a long standing requirement for switches, circuit breakers, MCC's, panelboards, switchboards, etc.

It started really back in 2005 when language was added to for instance NEC 409.110. Prior to the 2005 edition industrial control panels and HVAC was considered utilization equipment despite the fact that it does switching and overcurrent protection. A lot of hidden surprises lurked inside of Listed Assemblies. We had for instance NEC 430 for motor starters but that applies to assemblies, not components. Because of the prohibitive cost of seeking UL Listing for each and every industrial control panel separately, UL 508A was created in response which gives specifications for industrial control panels. Under these rules the manufacturer self-certifies the Listed aseembly and stamps it. UL 508A as I said reads very similar to NEC except that only 60 degree C rise wiring is allowed. Everything can be rated higher such as 75 or 90 degree C terminals for customer wiring but internally wiring must be sized to 60 degrees C rise. Panel shops have to be inspected initially and so far it looks like annually, and pay fees to UL for every labelled panel that they produce.

In 2008 in response to obvious complaints that industrial control panels that contained strictly control components and did not supply loads such as motors, lighting, heating, appliances, or receptacles were exempted from the SCCR Listing requirement, in keeping with the idea that distribution and utilization are different. NEC 409.110 wording was adjusted slightly to allow for this exemption.

And finally we come to NEC 2011, 409.22 which is your concern...you can't put industrial control panels that contain distribution-type components where the SCCR rating exceeds the available fault current. Since I've done a huge amount of work with power distribution, medium voltage systems, and addressing arc flash and coordination issues, this seems pretty straight forward to me. The companies that I've worked in/with generally go by the latest Code edition so this was a big deal back in 2010/2011 but today when we're aiming more for driving available fault currents and the like down to address incident energy, I tend not to think much of short circuit ratings which is the very first part of the analysis.