No electrical disconnect for A/C

[tnpappas]

There is no electrical disconnect near the compressor cabinet. The house is forty years old so I don't know if this was not a requirement at the time or not. Should this be written up as an improvement or improper installation since this system is eleven years old?

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[Jim Katen]

There is no electrical disconnect near the compressor cabinet. The house is forty years old so I don't know if this was not a requirement at the time or not. Should this be written up as an improvement or improper installation since this system is eleven years old?

It's wrong now because it was required 11 years ago when the equipment was installed.

Even if someone wanted to argue that point, it's still wrong because the in-sight disconnect was required in the 1968 NEC (Back then, it was in section 422.26)

- Jim Katen, Oregon

[Tom Raymond]

One more thought, even if you can conjure a scenario where the disconnect wasn't required at the time of install, it is unsafe for someone to work on that equipment in it's present state. Tell your client that it's hard enough to find a good HVAC guy, it will be harder still when they electrocute the first guy out there.

Tom

[Brandon Whitmore]

What's the reason for allowing lock out devices on breakers for furnaces, but not for AC units. They get the job done just as well, don't they?

[Jim Katen]

What's the reason for allowing lock out devices on breakers for furnaces, but not for AC units. They get the job done just as well, don't they?

That's a good question and I don't know the answer. I suspect that the answer is rooted in the byzantine politics of the NEC code writing process.

One thing that’s interesting is that, in the '68 NEC, a lockout was acceptable.

I don't know when they changed it and I don't have time to look it up right now. But, if someone reminds me, I can get to it later this week.

- Jim Katen, Oregon

[Brandon Whitmore]

Jim,

When they make a code change, is there always a way to determine the reasoning behind it? Something like a code commentary.

[Jim Katen]

Jim,

When they make a code change, is there always a way to determine the reasoning behind it? Something like a code commentary.

Well, there is an NEC handbook, which includes commentary and explanations, but it's remarkably unhelpful most of the time. It's privately published and is oftentimes just the opinions of the author; it has no official weight.

The interesting stuff is in the Report on Proposals (ROP) and Report on Comments (ROC) that are published as part of the code revising process with each cycle.

For instance, here are the ROPs and ROCs for the 2008 edition:

http://www.nfpa.org/itemDetail.asp?cate ... e%5Ftest=1

If you're interested in the politics of the NEC and how things do or don't get done, you could easily while away the hours reading that stuff.

- Jim Katen, Oregon

[Brandon Whitmore]

Thanks Jim.

[ghentjr]

How about the proximity to the gas meter?

[Jim Katen]

How about the proximity to the gas meter?

It doesn't need an in-sight electrical disconnect.

- Jim Katen, Oregon