hey all,
i want to turn some basement storage space in a storage building into a small shop. currently there is only a lighting circuit, an H2O heater on a 30 A breaker from the main panel, and a gas heater with a blower on a regular 20A circuit also from the main panel. no outlets in this space as of yet. Main panel is a 125 A panel. There are currently about 8 or 9 lighting and receptacle circuits (7 – 20A and 1 or 2 15A) including those I already mentioned. There used to be a range at 50A which is no longer in use and some electric heat at 30A that is also no longer in use. My plan is to remove the 50A breaker in the main and replace with a 60A to feed a subpanel in the basement,(run new #6 NM cable to subpanel). Then I would like to add 4 20A branch circuits and 1 15A for lighting from the new 60A subpanel in the basement. Any reason why this would not work? Tools I will be using in the basement are mostly small, less than 13A. The largest would be a contractor table saw that pulls about 15A and a compressor that also pulls about 15A at max. The rest of the tools are routers, sanders, drills, etc. All hand tools.
Does this sound adequate or even too much?
Thanks for the response.
brad.
Replies
I would go with a 100 amp
As a grandson of a cabinet maker that had only 60 amp service to his shop, you will be fine. As a single worker, you will not need more than a few machines running at once. Grandpa got by running his cabinet table saw, jointer, bandsaw, etc on 60 amps.
Of course like Brownbag said, I would go with 100 amps if I were doing it new. As long as the existing panel will accept a 100 amp breaker.
Frank DuVal
You can never make something foolproof because fools are so ingenious.
I think 60A will be plenty for your proposed shop. I had to read the post again to figure out that the HWH and gas heater were already on home runs to the main panel and not being moved to the subpanel.
You are proposing a one man shop - figure your maximum load - probably a scenario like this: running the table saw with a shop vac for dust control and the compressor kicks on because of some miniscule leak. Saw=15 + shop vac=10? + compressor=15 == 40A @ 120v. Even if you throw in another 20A for lighting, radio and tool battery chargers you are still only at 50% of the breaker capacity, and then only briefly until the compressor stops.
In a workshop situation you will probably find it helpful to mark the outlet cover plates with the breaker number and red / black designations to help distribute the heavier loads. Not so much to avoid tripping breakers but to provide the highest voltage available to your tools, a tool with full line voltage is a happy tool. Example: table saw is already pulling 15A on the red leg - plug the shop vac into a black leg outlet - both tools now have the benefits of full line voltage.
Good plan on the 20A circuits from the subpanel - minimize / eliminate nuisance tripping on tool start up - compressor and table saw especially.
Luck!
Jim
Never underestimate the value of a sharp pencil or good light.
right, the HWH and the existing lights are staying on the home runs to the main panel so this new panel is only new circuits for my tools, etc. 60 Amps seems plenty. Thanks for the response.
To continue with JTC's thought on the outlets, I used different color outlets in my shop to designate the 3 different circuits. I alternated two circuits on the wall (every other outlet) and the third on ceiling outlets. That way I can easily identify which circuit I have different equipment plugged into.
i like the idea of different color outlets for different circuits. i was planning on running 12/3 cable to double gang boxes so that I could have two circuits in each box and keep loads balanced at each work station.
Good idea with the double boxes - I placed singles every 3'. I would have had less holes to cut in the drywall when I hung it if I went with doubles! I didn't think to use 12-3 until after the fact. It would have saved me pulling the other line. I assume you're sharing the neutral on the two circuits? I'm sure you know this, but in case some other folks lurk here like me to learn, make sure you have your hot's out of phase so the neutral isn't carrying twice the load.