Circuit Breaker in Question

What they are saying is that the AIC rating applies only to the breaker itself, it is not intended to be used in determining the suitability of downstream devices. In other words, just because your breaker is rated for 65kAIC, that means nothing with regards to the device downstream of it, say for instance a motor starter with an overload relay. Most Oover Load Relays (OLR) are only capable of withstanding a fault current of 5kA. So if the fault level is 60kA, the breaker will survive, but the OLR will become shrapnel.

However new rules, at least here in North America, now require what is called an "SCCR" listing on all electrical systems or equipment. SCCR is short for Short Circuit Current Rating and is defined in the National Electric Code. You must now label everything with an SCCR so that you (and an inspector) will know if something needs additional current limitation in order to survive a high magnitude fault. Manufacturers of Current Limiting Fuses were quick to jump all over this and you can get more information from all of them now as to how Current Limitation works with fuses.

What they don't tell you is that most breaker manufacturers who also make motor controllers now publish what are called "Combination SCCR" listings using their own devices as well. So for example, if you buy a Siemens Circuit breaker that is rated 65kAIC, and use it with a Siemens Contactor and a Siemens OLR, even though the OLR itself is only rated 5kA withstand, the entire combination itself has been tested and listed at 65kA under the Combination SCCR Listing.

All of this just means that in the past, we tended to ignore the issue of "withstand ratings" because they were not official, but now they are by virtue of the SCCR listings. That statement you read is what breaker manufacturers must now use to start informing the public that they need to be cognizant of these issues.