I am upgrading branch wires in a house from aluminum to copper. Replacing all boxes... switch/outlet/receptacle/lighting, etc.. The house currently has a main panel (or lug not sure which.. maybe lug because there is no "main" breaker) next to the meter. The main panel is aluminum rated and has all aluminum wiring. The sub panel in the garage is also aluminum rated and has all aluminum wiring. The service wire is aluminum. Here is what I want to do:

1. Move the sub panel from the garage (now a bedroom) into the utility room with the washer/dryer/water heater.

2. Upgrade the panel to a newer copper rated one with more breakers and use copper wiring i.e, Romex.

3. There are a few circuits in the current "main" panel. I want to stop using them since they are aluminum and move them to that sub panel inside. My sub will feed all branch circuits and the main will serve only as a disconnect.


I still need to determine my service amps to the meter, size of current main panel(lug) and service wire size to ensure I don't get a new sub panel that is too large for the service. It's an older home built in the 50s, so I'm assuming I'm lucky if I have 150 amp service.

My questions:
1. Can I use the existing aluminum main panel and service wire with a new copper rated sub panel?

2. if yes, Can I extend the service wire using typical methods such as splicing in an appropriate sized junction box?

3.. If yes, What should I use to splice the aluminum service wire?

4. The writing on my wiring is not legible.. how do I determine size? A simple sizing tool?

Thanks for the help. I've done this before, quite some time ago and it seems that the service wire I used was aluminum anyway. From the City transformer to the meter and again from the meter to the main.

Don't get concerned if a panel is copper or aluminum, both operate the same. And neither require a certain type wire.

You need to get a handle on the size service you have. There must be a Main Breaker someplace, what is is rated?

You can also call the power company and ask them.

I'm curious, are you going to abandon the aluminum in the walls and fish the NM cable or are you going to remove the aluminum and replace it with the NM?

AL wire is safe wire if it is installed properly. The problems start with devices (receptacles and switches) that are listed for copper.

Copper and Aluminum heat and cool at different rates. This causes loose connections. Loose connections cause heat, heat causes fire.

I am going to remove the wire I am able to move and leave in place the wiring I can't remove (stapled inside finished walls). I will use Romex throughout. The aluminum wire looks like it's 14 and probably rated at 15 amps. We want 20 amps throughout. We did so much framing, most of the wires are exposed and need to be moved/extended/or replaced anyway, so we thought... why not bring it up to modern standards? We also don't want a mix that may confuse any future changes.. i.e, the homeowner replaces a switch rated for copper on an aluminum run..

It's strange... there is no "main" breaker. Only 2 panels that have individual breakers.. I am guessing these are lugs. The main panel next to the meter says it's rated at 150 amps as does the interior (sub) panel. Still trying to read the writing on the service wiring. The only thing I can make out is 600V. Thanks.

FYI - Current code allows for either Copper or Aluminium.

However, I agree with you. I would much rather have copper than aluminum. I need to do exactly what you are doing.

If you have a main disconnect switch between the meter and the service panel you are fine. If you are using a "Main Lug Only" panel, you would have to be able to cut the power to the panel by shutting off the first six breakers.

This type of panel would more than likely be a split bus panel.

Send photos of your meter, service entrance conductors, open panels, anything you can.

The more the better, so we can see what you have.

Ok. Thanks. I will. I'm heading over there in the morning. I'll take plenty of pics.