Does a Kirk key interlock need to be installed?

I’ve installed quite a few of those for Lowe’s. It’s electrically and mechanically interlocked. Walmart and a lot of distribution centers use the Kirk key type.
Which are almost never subject to NEC 700 or 701 requirements.
 
If it's not a code issue, our local utility would still absolutely prohibit not having interlocks or a transfer switch.
 
This article from IAEI uses the terms transfer equipment and transfer switch.
One example given of transfer equipment is PLC controlled breakers.
I disagree with the article as the use of interlocks is not currently permitted for that application. Yes, it is a common practice, but the acceptance to my PI to add interlocks to 702.5 for the 2026 code indicates that it is not specifically permitted by the current code.
 
I disagree with the article as the use of interlocks is not currently permitted for that application. Yes, it is a common practice, but the acceptance to my PI to add interlocks to 702.5 for the 2026 code indicates that it is not specifically permitted by the current code.
Did they give you a definition of interlock?
Clearly the article I reference considers a PLC controlled set of breakers as being different than a simple mechanical interlocked set.
 
Did they give you a definition of interlock?
Clearly the article I reference considers a PLC controlled set of breakers as being different than a simple mechanical interlocked set.
The interlocks are physical mechanical interlocks like breaker interlocks or a Kirk-key system.
No idea of what the PLC system would actually be listed as.
 
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