Here is a thought, maybe you can double up some of your spots with twin breakers. I have use these in the past. I chose Square D but I think they all make them.

http://www.pacificcoastbreaker.com/catalog/1589

What Randy said.

A breaker box that can hold 30 "single-sized" 120V breakers are often rated for 40 circuits. The bottom 10 slots can take those "double" or "tandem" breakers. Usually there is a mechanical interlock that only lets you put in the 10 breakers. Differs from manufacturer to manufacturer.

So if you get a couple of tandem breakers, you can free up room for a 240 breaker. There should be some marking on the box to tell you how many circuits it's rated for.

Like Randy, I also like/use Square D (great minds think alike, and fools seldom differ :laugh.

Pete

I will have to disagree with Randy and Pete on this one...I don't like the tandem breaker idea except for a last resort.

To me, it sounds like your garage shop is expanding...so there is a good chance even more power options will be needed in the future. SO, take this opportunity to add a 100 amp sub-panel in your garage. You can use the breaker space that feeds your compressor now to feed it, then run the compressor and the new welder from the sub-panel as well as some 20A 120V circuits. It will cost more now-but you will never be sorry for doing the upgrade.

At the risk of sounding wishy-washy, I put a 100 amp sub panel in my garage. All time and money decisions. So if you can swing it, I'll agree with Kenny even though he disagrees with me :crazy:.

Verify with local electrician, but I believe you are allowed to use #4 wire for that 100 amp sub panel for residential use. It could save you some money depending on your wire source. Continuing with my wishy-washy theme here, I used #2 wire because it was cheaper to buy that at Lowes than buy the #4 wire (when getting 500').

If you do switch things around (by using tandem breakers), I'd put low typical load stuff on the tandem breakers.

Pete

Yep, just a matter of whether he wants to do it quick and simple or plan long term and more cost. Life is full of choices.

Time to add a sub-panel. Pete should be able to confirm that a sub-panel can be 80% the size of the original (e.g. main panel = 100amps, sub-panel can be up to 80amps).

:thumbup1gif:

I had to do that in my house. It's easy.

Kennyd said:

add a 100 amp sub-panel in your garage.

Click to expand...

They added a sub panel for my Geo-thermal. It was cheaper to run the heavy wire once to the box than many times for all the big draw items (pump, water heater, resistance heat for back up). It is the best solution, but not the only way, as Randy said.