125A A/C...

[1793]

Thought I would share this one:

I have a customer who is having the siding removed and replaced with HardiePlank. I was asked to remove the A/C disconnect and as I was tracking down the breaker, I found that the A/C AND furnace were fed with a 2/0 AL SEU and a 125A breaker.

 

[dicklaxt]

That big old aluminum 2/0 coming in then reducing at the block to what, maybe #8 copper?

Explain that little bit of trickery,,,,,,,,,,


dick

 

[kwired]

Not easy to tell exactly what you have but here is my guess from what I did see.

Used to be an electric furnace and the need for a 125 amp supply was a valid one, the feed to the AC unit probably violated some rules though. Now they have a gas furnace and simply supplied it from the original circuit - Adding more problems with overcurrent protection, as well as adding a neutral conductor to what was originally only an equipment grounding conductor.

 

[1793]

Not easy to tell exactly what you have but here is my guess from what I did see.

Used to be an electric furnace and the need for a 125 amp supply was a valid one, the feed to the AC unit probably violated some rules though. Now they have a gas furnace and simply supplied it from the original circuit - Adding more problems with overcurrent protection, as well as adding a neutral conductor to what was originally only an equipment grounding conductor.

Yes there was an electric Furnace at one time and yes they reworked the old panel at the Furnace, removed the secondary breakers an installed the pictured terminal block. They kept the main feed breaker, 125A. To make things even worse the cable was actually a 1/0 AL SEU. The A/C cable was 10/2 NM and the furnace was 12/2 NM, both protected by the 125A breaker.

I had to rework the A/C disconnect and whip and when I opened the A/C i found the following: