Maximum Ampacity for Aluminum Feed

Randell Tarin

What is the maximum ampacity rating for #000 three-conductor aluminum?

Stubbie

In general terms the maximum is 175 amps but may be less depending on how you are using it and the insulation covering of the wire and the terminal temperature rating of the equipment your connecting to.

Randell Tarin

It's underground feed to a sub-panel. We've been through this before in another thread on the proper way to set up this particular panel. However, my original requirement for a 100 AMP sub has grown to 125 AMP.

I just wanted to make sure I had it covered with the feed. Otherwise, I was going to have to scale things back on my total load.

Stubbie

You may have an issue with connecting 3/0 to the mains of a 125 amp load center.

Randell Tarin

How so? Are you talking about wire size in the main breaker?

Speedy Petey

Yes. I also doubt you will easily terminate that 3/0 anywhere in a 100A panel.

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Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

Randell Tarin

OOPs! My Bad. It's 1/0 not 3/0.

I ran the feed several months ago and kind of forgot what I had. I just now compared the wire size with the main breaker opening. It fits.

However, back to my original concern. Maximum amperage for 1/0 Aluminum.

Speedy Petey

125 Amps

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

Randell Tarin

By the skin of my teeth!

I'm sure I won't exceed 125 AMPs on this panel, in fact it probably won't exceed 100 amps, so I have a little flex built in.

Thanks guys.