Electrical contractor 37 years. Electrical inspector 2 years
I see these interlock kits installed a lot but never used one. What are the NEC code thoughts about these? Not peoples opinion. Personally I think some of them are a great idea. Others could be dangerous. I referenced 702.4.B and B.1. Also 702.5. This tells me that the aftermarket ones that you mount to the cover should not be allowed because if the cover is off then there is no interlock feature. You are also drilling the panel cover. Is this altering the panel listing. Can you install brand X interlock onto brand Y panel? I like the type that fasten to the breaker instead. 702.4.B and B.1 talks about system capacity. Does this mean Suzy home owner decides what load is to be connected? I have seen a 7500 watt generator feeding a 200 amp, 40 circuit panel. These interlock kits are much cheaper to install so I might switch to them. If I ask 5 different AHJ then I get 6 different answers.