Dedicated line or sub panel?

[Rezarf]

I moved into a 3 car garage (well house actually) last year and my honey-do list is drawing to a close and would like to add a little flexibility to my garage wiring.

I would like to run my:

Welder (220v)
Compressor (220v)

I have 2 20amp lines in the garage already so I am pretty set for other usage.

My run from my main box is about 60' and I have access to the basement joists as it is unfinished. I am trying to decide if I want to run a dedicated 50amp line to the garage or run a subpanel. I haven't needed the compressor and welder at the same time yet, and doubt I will in the future.

So what say you? Subpanel? Or a direct line?

If I run either, what gauge should I be looking at? I was thinking 8/3 or 6/3 romex for a dedicated line or sub panel. I had a friend who does a lot of remodeling suggest wiring the subpanel with aluminum then running copper for two circuits from a sub panel.

Thanks in advance-

 

[pattenp]

Do what your friend suggest, that will give you more flexibility. But the cheapest solution would be to run the dedicated line. If you do the 50A dedicated, run #6CU. Use AL SER cable to feed the sub-panel if you go that route. The SER cable size depends on the amps you want the sub to provide and the space and capacity the main can handle.

 

[Naq]

Sounds like the garage is attached. A detached building will have different requirements.

How long do you plan on owning the space?
How much and what kind of work do you plan on doing in the garage over the next couple years?
What electrical tools/equipment could you see yourself buying/using over the next couple years?
When you think of your dream garage, what does it look like?
How much do you feel like spending now? Next year? In the future?

If you run a single branch circuit the electric motor compressor will have different requirements than the electric welder in general so you should start another thread to vet your design if you go that way.

I would put in a 100A subpanel, move the 2 existing circuits to it and grow into it, but that's just me. I have some other projects I can spend your money on if you like as well.

 

[cowboy73]

I would put a 100A subpanel in the garage. Gives you alot more room for future circuits in the future. Do it this way and you won't regret it a few years down the road when you need more circuits in the garage.

 

[Norcal]

Do what your friend suggest, that will give you more flexibility. But the cheapest solution would be to run the dedicated line. If you do the 50A dedicated, run #6CU. Use AL SER cable to feed the sub-panel if you go that route. The SER cable size depends on the amps you want the sub to provide and the space and capacity the main can handle.

Just a FYI, 6 AWG AL SER cable is only good for 40A, since the 2008 NEC, SER is sized from the 60 degree column of table 310.16 just like NM cable.
For 100A 1/0 AL SER is required.

 

[pattenp]

Just a FYI, 6 AWG AL SER cable is only good for 40A, since the 2008 NEC, SER is sized from the 60 degree column of table 310.16 just like NM cable.
For 100A 1/0 AL SER is required.

I wasn't suggesting #6AL for a sub-panel feed if that's what you're thinking. I said #6CU for a single use dedicated 50A circuit.

Oh and by the way 2011 NEC it is now table 310.15