ECN Forum Forums General Topics of the Trade General Discussion Area Alum/Copper bus Panels

I had a service call today that relates to bus material choice. 20 year-old General Switch 100A MB 20ct panel w/alum bus mounted on the outside concrete block wall of a basement. HO had called the utility because the lights were flickering off and on for about 10-20 seconds at a time for the last few weeks. This past weekend half of the lights would go off and stay off for 10-15 minutes then come back on. The utility came out today and checked all the connections on their side and told her to call me. The panel looked okay. Neat original installation. #2 copper THHN entrance conductors in 2" rigid. I removed the cover and sat there for 15 minutes just listening. I had the HO go turn on all the lights in the house then I heard the sizzle sound coming from the main. I pulled the meter and removed the main breaker. It is one of those mains consisting of a 2 pole 100A breaker stabbed onto the top of the buses. One of the bus clips on the main was smoked and spread out. The aluminum bus was corroded. I cleaned up the bus and replaced the main with an ITE 2 pole 100A breaker which not only fit the bus but also accepted the hold-down retainer clip. This is a temp fix as the HO wants a new panel ASAP. There was some minimal rust on the backside of the enclosure. No backer board between the panel and the block wall. Washer/dryer located near by and the dryer vent went out the block wall 3' from the service. Moisture, I believe, contributed to the demise of the aluminum bus. I don't believe it would have had the same effect on a copper bus in the same time frame.

It looks like I had the wrong company--I spent almost half an hour roaming around the Square D web site looking for their remodel panels, with no luck. It looks like it was Cutler-Hammer I was thinking of. Here are a few Cutler-Hammer part numbers:

CH22B100CRN
CH32B150JRN
CH32B200JRN
CH42B200KRN

I hope that helps!

--Solar

[This message has been edited by SolarPowered (edited 09-28-2004).]

Solar,
We use CH on upgrade work, when a customer requests SQ D we have to do all the splicing in boxes outside thr panel, so we try to stay with the CH, there are some areas that the inspectors will let it slide if you have a panel full of splices, but not in my area.

We use Siemans with copper bus. Some towns require it and I have some customers or blue prints ask for it. I never had a request for AL busses. To make my life simpler I just make them all CU instead of tring to keep track who gets what. I don't know if there is much differance in price.

We allways block the panel of a basement wall. I see so many expencive trac homes with the panel on the cocrete. After just a few years it is starting to show signs of deteration.

Tom