HVAC Compressor Shut-Off

[Joe Reilly]

Ok folks, I am reviewing 2012 IRC / 2011 NEC and noted that my question is not truly answered. So I go out to everyone else.

Question is related to an HVAC compressor disconnect.

This disconnect is within site of the unit. (Not a question)

1.) This disconnect is only about 6' inches off the ground, (which I find nothing noting height requirements)

2.) The question becomes, the disconnect was a standard electrical switch and when I say standard I mean a typical light switch. Does it have to be fused within site, or will the shut-off work this way. (Note this was on a Condo)

[Jerry Peck]

Question is related to an HVAC compressor disconnect.

This disconnect is within site of the unit. (Not a question)

Within sight of, and within 50 feet of, no obstructions between the two. Sometimes there will be a fence, bush, or something else which could obstruct the view from the outdoor unit to the switch which would make it non-compliant.


1.) This disconnect is only about 6' inches off the ground, (which I find nothing noting height requirements)

Correct - no minimum height (logic says that is stupid to do, but codes are not logical) ... however ... if you are in a flood hazard area (that big IF) then minimum height is dictated by the flood aspect which applies.


2.) The question becomes, the disconnect was a standard electrical switch and when I say standard I mean a typical light switch. Does it have to be fused within site, or will the shut-off work this way. (Note this was on a Condo)

That's a two part question, which needs a two part answer:

a) "a standard electrical switch and when I say standard I mean a typical light switch"
- - Are you sure? If that is the case, then that switch is almost guaranteed to be NOT rated for that use.

b) "Does it have to be fused within site, or will the shut-off work this way."
- - The "disconnect" which is required is just that, a "disconnect", no overcurrent protection is required at that "disconnect".
- - Which brings up a third part to the answer:
- b2) Overcurrent protection: (breaker or fuses)
- - - follow the nameplate rating for the minimum and maximum ratings for the overcurrent protection device(s).

[Jim Luttrall]

Almost all of these will be a double pole switch rather than a single pole like a traditional wall switch unless it has been changed by someone after installation (think complex maintenance). NEVER trust one. ALWAYS test before performing service.

[Jerry Peck]

Almost all of these will be a double pole switch rather than a single pole like a traditional wall switch ...

Nonetheless, if it looks like a 'regular switch', it likely is not properly rated.

[david shapiro]

b) "Does it have to be fused within site, or will the shut-off work this way."
- - The "disconnect" which is required is just that, a "disconnect", no overcurrent protection is required at that "disconnect".
- - Which brings up a third part to the answer:
- b2) Overcurrent protection: (breaker or fuses)
- - - follow the nameplate rating for the minimum and maximum ratings for the overcurrent protection device(s).

To expand on Jerry's comment, if it happens that the equipment specifies a maximum fuse rating and says nothing about CB protection, in that rare case the logical thing is indeed to provide a fused disconnect. In that case, it needs a suitably rated fuse somewhere upstream or it's a 110.3 (listing) violation.

[Mike Clarke]

Nonetheless, if it looks like a 'regular switch', it likely is not properly rated.
Have seen commercial light switches that are double pole (needed for 240V/277V) with rating up to 30 amp some versions, could be that is what it is maybe ?