4 units, 3 breakers

[dbucknavich]

Got into a messy one here. 5,500 sq ft, 20 years old. No problem right? Wrong. Should be getting more money for this but oh well, you win some and lose some.

Here's the system. 4 units. All package units on roof. 3 are electric heat pumps (various ages). 1 is a gas pack (newer).

Anyway, one thing that caught my attention is the HVAC wiring. I noticed 3 220 breakers labeled North AC (100 amp), Master Bed (40 amp), Master Bath (40 amp). Now there were units over each of these areas so we're good there. However, there was a 4th unit that I could not find another 220 breaker for. No subpanels around either. Only one of them matched the required max breaker size, so it's a referral to specialist regardless. My question is where is the 4th unit getting power from? I know not being there makes it tough to help, but any input would be great. What kind of methods have you seen when discovering this?

[Michael R. Boyett]

100 amps for the North AC seems high...could 2 units be on that breaker?

[Brian E. Kelly]

Originally Posted by mboyett

100 amps for the North AC seems high...could 2 units be on that breaker?

Sounds possible to me also Dylan.

[dbucknavich]

Originally Posted by mboyett

100 amps for the North AC seems high...could 2 units be on that breaker?

That's my guess. And none of them have a max breaker size of over 40. Man, my head is still spinning from this one so I'm a little cloudy. I'm going to say that is likely scenario.

On top of that, 2 water heaters, one of which leaks. One steam system, which leaks. Do it yourself drainage pipes, all leaking...lots of black spots everywhere. Only asking a million 5 too.

Beer me now.

[Marc D. Shunk]

If the one was just a gas pack with no a/c, it's possible that it only had a single 120V circuit going to it.

[dbucknavich]

Originally Posted by Marc D. Shunk

If the one was just a gas pack with no a/c, it's possible that it only had a single 120V circuit going to it.

It had ac too. That was the big boy newer unit to boot.

[Jeffrey R. Wicklander]

Do you know if the disconnects for each of the heat pumps were fused accordingly?

Jeff

[dbucknavich]

Originally Posted by jwicklander

Do you know if the disconnects for each of the heat pumps were fused accordingly?

Jeff

They were. But don't they still have to be on separate circuits?

[Jeffrey R. Wicklander]

Sorry for the delay... was watching the end of the football game.

in the NEC, 430.53 states that you can use multiple motors on a single branch circuit if conditions are met. If the smallest heat pump (of the two on that branch circuit) is rated between 30-40 amps and the conductors feeding the two heat pumps are sized according to the overcurrent protection device (breaker), it should be ok.

430.53(B) states that the OCPD shall not exceed the rating of the smallest motor according to 430.52. If the rating of the smallest pump is 30-40 amps, according to 430.52, the OCPD should be 90-120 amps (the largest you saw in the panel was 100 amps). The conductors coming off the breaker should have been #3 CU wire. I believe that if these two specific conditions were met, the set-up will be fine.

Jeff

[dbucknavich]

Thank Jeff. Just thought I'd follow up.

After a closer look, the 2 gauge wire coming from the "AC N" breaker actually rears its ugly head again in the pool sub panel. So its off to the electrician for now. Out of my hands and I wouldn't have it any other way.