Lock Switch On

[Adirondacker]

There is a 100 amp fused disconnect a public hallway that feeds the general power for receptacles and lighting a particular suite. The tenant would like to have this disconnect locked into the "On" position so no-one can simply turn off his power.

Is this permissible according to the NEC?

Thanks for the help.

 

[petersonra]

Why would this be an NEC issue?

The disconnect is there so that it can be opened to work on the circuits. Presumably the person who would be doing that would have access to the key.

 

[Adirondacker]

The tenant wants to keep the key. The building manager is concerned if there was a problem, someone would first have to find the key to shut off the power.

I am thinking it is not going to be considered readily accessible but not sure how to interpret it.

 

[steve66]

I agree. Its allowed as long as people who need the key have access to the key.

If memory serves me right, Square D General Purpose disconnects are only lockable in the off position, but the Heavy Duty kind are lockable in either position. I assume other manufacturers would be similar.

So if you haven't got the disconnect yet, you might want to make sure its lockable in the on position.

 

[charlie b]

The building manager is concerned if there was a problem, someone would first have to find the key to shut off the power.

True, but irrelevant. Circuit breakers and disconnect switches are not intended to serve the purpose of emergency shutoff. That is not their job. They protect conductors against overcurrent (that is, circuit breakers and fused disconnects do that job), and they provide a means of allowing safe maintenance. That is all they do.

I am thinking it is not going to be considered readily accessible but not sure how to interpret it.

And there is no requirement for them to be readily accessible. So it does not matter, at least from a code perspective.

 

[barclayd]

I am thinking it is not going to be considered readily accessible but not sure how to interpret it.

A lock in not relevant to the Article 100 Definition of Readily Accessible.
db

 

[tom baker]

Its no different from an electrical equipment room that is locked. See 110.26(G), which specifically allows locking an enclosure.

 

[bluesmoke...oops]

The building manager is concerned if there was a problem, someone would first have to find the key to shut off the power.

If it is that big of a problem I'm sure someone has bolt cutters

 

[brother]

The tenant wants to keep the key. The building manager is concerned if there was a problem, someone would first have to find the key to shut off the power.

I am thinking it is not going to be considered readily accessible but not sure how to interpret it.

I hear about the building manager, and the tenant(renter) but what does the owner say??? That's who makes the call.

 

[Pierre C Belarge]

True, but irrelevant. Circuit breakers and disconnect switches are not intended to serve the purpose of emergency shutoff. That is not their job. They protect conductors against overcurrent (that is, circuit breakers and fused disconnects do that job), and they provide a means of allowing safe maintenance. That is all they do. And there is no requirement for them to be readily accessible. So it does not matter, at least from a code perspective.

See 240.24(A) & (B)