7th Kahuna
Well-known member
Back in January I asked for help in locating an unusual gauge SE cable to run from the main panel to a new sub-panel in the garage. I was pretty definite that I wanted it to be copper rather than aluminum. My dad wanted cooper for safety. He has heard the stories about aluminum wire causing fires. I wasn't so worried about that. We know what we need to do to prevent or at least significantly reduce the risk of fire. No, I wanted copper because of the route I was going to need to pull the cable through. I thought, though heavier, it would give more easily around the bends.
By the time I got the wire, there were so many other things in the walls I almost gave up before I started and just surface routed it. Couldn't do that. In the end it went much smoother than expected.
So why use aluminum over copper? Simple, cost. But I wanted to post this for another reason. After the inspector had signed off the panel and in fact was already back in his truck, he stopped and asked me if I had used aluminum, he had seen the anti oxidant paste under the lugs. I said no copper. Why the paste, he asked. Because the lugs were aluminum. You over thought it, he said and laughed. And then he shared something I thought was important to share with you all:
Per this building inspector, aluminum feeders are allowed for the main panel but aluminum is no longer allowed between a main panel and a sub panel. Why? Fire.
Perhaps others have covered that here, but no one mentioned it in my previous thread. He didn't give me the impression he would have made me tear it out, especially given that he had just signed it off, but now I'm doubly glad I used copper. I need to get my hands on a current copy of the code.
The other question that came up in that thread was whether or not I actually could run 1-1-1-3 SE cable into my main panel. I needed 1-1-1-3 Copper SE cable to support a 125 amp sub panel. Turned out the answer was no. I'm very thankful someone asked. The largest I could use in this panel was 2-2-2-4 (which by the way can very easily be ordered from Lowes and may qualified for free shipping). Anyhow, 2-2-2-4 will support up to 110 amps. Hopefully I can find a 110 amp Square-D breaker. So far no luck. 90 amps yes, 110 no. Seems odd to me.
By the time I got the wire, there were so many other things in the walls I almost gave up before I started and just surface routed it. Couldn't do that. In the end it went much smoother than expected.
So why use aluminum over copper? Simple, cost. But I wanted to post this for another reason. After the inspector had signed off the panel and in fact was already back in his truck, he stopped and asked me if I had used aluminum, he had seen the anti oxidant paste under the lugs. I said no copper. Why the paste, he asked. Because the lugs were aluminum. You over thought it, he said and laughed. And then he shared something I thought was important to share with you all:
Per this building inspector, aluminum feeders are allowed for the main panel but aluminum is no longer allowed between a main panel and a sub panel. Why? Fire.
Perhaps others have covered that here, but no one mentioned it in my previous thread. He didn't give me the impression he would have made me tear it out, especially given that he had just signed it off, but now I'm doubly glad I used copper. I need to get my hands on a current copy of the code.
The other question that came up in that thread was whether or not I actually could run 1-1-1-3 SE cable into my main panel. I needed 1-1-1-3 Copper SE cable to support a 125 amp sub panel. Turned out the answer was no. I'm very thankful someone asked. The largest I could use in this panel was 2-2-2-4 (which by the way can very easily be ordered from Lowes and may qualified for free shipping). Anyhow, 2-2-2-4 will support up to 110 amps. Hopefully I can find a 110 amp Square-D breaker. So far no luck. 90 amps yes, 110 no. Seems odd to me.
