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My county uses the 2014 NEC with no modifications. I'm wiring my newly built detached garage myself.

I had the rough-in inspection, and everything was ok for it, but the inspector had some concerns about my 50A outlet that might be a problem during the final inspection.

It is a NEMA 14-50 receptacle (non locking) that I installed for EV charging. He said people usually put a disconnect on it for plugging in welders and stuff, but since I'm using it for an EV, I could put a lock on the breaker instead (he said to look for water heater locks).

I understand the disconnect from a safety/convenience factor for things that might immediately draw current when plugged in and arc... but I don't want to mess with installing a disconnect since the circuit breaker is ~20 ft away, unobstructed. The lock makes no sense to me.

I looked through the NEC and couldn't find any code suggesting a disconnect (or breaker lock)... is anyone aware of something like that? Just wanted to check before I question him more about it.

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Inspector is drunk.

The cord/socket is the disconnect device

The purpose of a disconnect switch, or a locking device on the breaker, is so that a craft or trade can “lockout/tagout” the equipment while it is being serviced or maintained.

There have been too many cases of Goober knowing where his machine’s breaker is, walking the 2nd floor and noticing his breaker is off, turning it back on, and then shocking the repairman on the 3rd floor who is (unknown to Goober) servicing the machine. Since Goober is on the 2nd floor and the machine is on the 3rd, Goober does not have line-of-sight to the machine and can’t see the repair cart and worker. If there was line-of-sight from panel to machine, the disconnect would not be needed.

However, this scenario presumes a hardwired machine. When the machine is cord-and-plug connected, the service person is expected to simply unplug it.

So there is no earthly reason for a disconnect switch on a plug-in machine. In fact there’s good reason to cord-and-plug connect a machine specifically to avoid the need for a disconnect.

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  • Thanks! I see. That's pretty much what I figured... just didn't wanna push back without some reassurance that it is indeed not necessary. – shaddow Jun 29 at 21:37

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