CaptKarnage
Member
- Location
- Milwaukee, WI
- Occupation
- Electrical Engineer
This is very similar, but not exactly the same question as this post here: https://forums.mikeholt.com/threads/prime-mover-capable-of-being-locked-open.2571057/#post-2793852
It pertains to NEC 2020 445.18 (Or NEC 2023 445.19) referencing section 110.25. Though I'm looking at a generator, I think the broader question here applies to more than just generators.
My generator is not a Generac generator as in the linked question, and has a bit different disconnect mechanism. It has the prime mover disable as a switch on the outside of the generator enclosure. When the switch is in the open position, you can't just simply press & flip the switch to close it, you have to first push up a thumb "lock" before you can switch it back to closed. I do like this feature, it's a nice little safety, but I'm unsure if this fully meets the intent of the NEC section.
If you take "lockable" in the broadest terms possible, this switch could be considered lockable. If, however, by "lockable" it is meant there needs to be a method to be able to perform LOTO (with keys & locks, etc.) then it certainly wouldn't meet this requirement. We are talking about a residential installation - so LOTO doesn't necessarily apply. That being said, main breakers often have a means to insert a bar that makes them lockable by key even in residential panels sometimes, though not as common as in industrial settings.
I don't see a definition of "Lockable" in the NEC. So the fundamental question here is what qualifies as "lockable"?
It pertains to NEC 2020 445.18 (Or NEC 2023 445.19) referencing section 110.25. Though I'm looking at a generator, I think the broader question here applies to more than just generators.
My generator is not a Generac generator as in the linked question, and has a bit different disconnect mechanism. It has the prime mover disable as a switch on the outside of the generator enclosure. When the switch is in the open position, you can't just simply press & flip the switch to close it, you have to first push up a thumb "lock" before you can switch it back to closed. I do like this feature, it's a nice little safety, but I'm unsure if this fully meets the intent of the NEC section.
If you take "lockable" in the broadest terms possible, this switch could be considered lockable. If, however, by "lockable" it is meant there needs to be a method to be able to perform LOTO (with keys & locks, etc.) then it certainly wouldn't meet this requirement. We are talking about a residential installation - so LOTO doesn't necessarily apply. That being said, main breakers often have a means to insert a bar that makes them lockable by key even in residential panels sometimes, though not as common as in industrial settings.
I don't see a definition of "Lockable" in the NEC. So the fundamental question here is what qualifies as "lockable"?
