Wiring For AC Units

Is this common? I inspected two forced air units (electric heat) in an attic today. There was “back up” wiring for each unit in the attic (see photo). Thanks!

Attic AC.jpg

Never observed this before does not make sense to me.

Most likely the systems are heat pumps and the electrician just decided to label unit #1’s emergency heat strips as Back-up #1. Ditto for unit #2. Well, maybe not, I now see at separate disconnect for “Furnace #1”.

Was there a genset present?

No genset present.


No clue - now if you had told me that it was a heat pump (very common in our area), I would say that “backup” likely refers to the electric elements that would supplement the heat pump on very cold days.

No heat pump but it is a total electric house.

Could this have been wired for a generator back-up?

I really don’t know. This is a new contructed home, built in 2006, that builder sold to investor to sell (never lived in). Since I’m coming up empty on an answer for their purpose, would you write it up for an electrician to evaluate or since wires seem to terminate properly in a box just note it as “back-up” wiring? :wink:


Can’t tell from the picture, but what is the wire size and does it connect to anything?

Don’t have th wire size off hand but the wires come from the unit and terminates in the box (pictured). Thanks

If there is nothing hooked up, what requires evaluating?

Just write it up in the report.
If they want to know what it is or use it, they can go get an electrician.

That would be speculating or more correctly “guessing” what something is. If you do not know something for certain the best thing you can do is say “I don’t know!”
Home inspectors need to get over this urge to be “all knowing, all seeing.” Write what you see, what you can’t see and for what reasons you can’ t see it, what you know for sure, but never, ever guess at anything. It will come back and bite you right in the keester. You can say it isn’t “typical” and that you’ve never seen anything like it but I would never guess at something just so I can say something for the sake of saying something. It is not a crime or should not reflect negatively to say “I do not Know” when you run across things out of the ordinary. I know for a fact I’ve done it at least once this past week.

That’s pretty much what I discussed and reported to my client. The reason for my original post was just to see if anyone else has seen a similar set-up. And if so, the reason(s) for having back-ups.

It my opinion they used these as replacement for sub-panel breakers