Copper/Alu same breaker

[Gary T. Heller]

My comment in the report is as follows.

The 220 volt breaker feeding the water heater has both aluminum and copper conductors. This is not a common practice but these conductors are sized properly for the 30 amp breaker they are connected to and the breaker is rated for both copper and aluminum.

What say you?

[Robert Meier]

Are these in a raceway? What size is the Al conductor?

[Christopher Currins]

Kind of odd 2 separate types of conductors serving the same circuit outlet .

[Jim Port]

It might be a shadow but the CU looks larger than the AL. You also might have issues if all conductors of the circuit are not run together.

[KEVIN WOOD]

Well done Jim.
I was wondering who would catch this one.

[Gary T. Heller]

They are not in a raceway. The Copper is stranded and larger than the solid Aluminum.

[Jeffrey R. Jonas]

Originally Posted by gheller

They are not in a raceway. The Copper is stranded and larger than the solid Aluminum.

Screech..... <<<slamming on the brakes>>>

If that is actually 'solid' aluminum, now I have an issue with it. (Other than what was said above). That would be enough for me to call it out.

Are you sure? Looks like strand aluminum from here.

[Jeffrey Moore]

what size are the wires as the Al should be larger if the copper is properly sized?


Is this a situation where the breaker has been changed at one time?

[Gary T. Heller]

The aluminum doesn't need to be larger than the copper. The copper is larger than what it needs to be. The aluminum needs to be one size larger than it would have to be if it were copper.

This is a fairly new Cutler Hammer panel. It appears to be proffessionaly installed on a home built in 1978. I cannot understand why anyone would use two differnet conductors. I stopped by the house today and did the panel and roof. I'm going back tomorrow to do the interior and the pool.

I appreciate all the comments. Jim...can you expand on the issues if the circuits are not run together?

[Jim Port]

Article 300.3(B) requires that all conductors of the same circuit be run in the same raceway or sheath. Article 300.20 also applies where the raceway or enclosure is ferrous that the conductors be run together to avoid inductive heating.

[Jeffrey Moore]

Originally Posted by gheller

The aluminum doesn't need to be larger than the copper. The copper is larger than what it needs to be. The aluminum needs to be one size larger than it would have to be if it were copper.

That is why I had in the question- if the Cu is properly sized, you did not state that the Cu was oversized

[Robert Meier]

Originally Posted by gheller

The aluminum doesn't need to be larger than the copper. The copper is larger than what it needs to be. The aluminum needs to be one size larger than it would have to be if it were copper.

Since these are not in a raceway then one could conclude that they are in two separate cables which is a violation as Jim has outlined. With a limited exception stranded conductors in cables, (the copper one in this case) start with #8 and larger, which means that the copper conductor is likely #8. According to your last sentence quoted above, for a 30 amp circuit the Aluminum conductor would also be required to be a #8 since #10 copper would be the minimum for a 30 amp circuit for a water heater load. So is the Al conductor actually a #8 AL or is this quote from the OP incorrect?

The 220 volt breaker feeding the water heater has both aluminum and copper conductors. This is not a common practice but these conductors are sized properly for the 30 amp breaker they are connected to and the breaker is rated for both copper and aluminum.