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Discussion Starter #1
I'm in the process of building my woodworking garage and want to install a new sub panel for my equipment. I'm not sure how I would go about sizing the sub panel to make sure it's adequate. Is there a ballpark figure I should be looking at for a typical garage workshop, like 60 amps? I think I was over estimating the size I needed at first as I was taking into account equipment that I will never run together. For example, I would never run my table saw and planer at the same time. Most of the time, I'll be running one machine at a time along with my dust collection and a couple other small things like radios, clocks, lights etc.

I'm currently running them off of the main panel with 20 amp circuits and the only tool that trips the breaker occasionally is my table saw which makes me believe the current draw required is right in the tripping point of a 20 amp breaker.

Any suggestions?
 

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A "Handy Husband"
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Is the garage attached or detached? How far from the main panel? How many empty slots do you have remaining?

If the saw has a plug in 120 volt motor, the max receptacle you can have is 20 amp. Perhaps you are plugging it into a circuit with other items using power at the same time. If so you need a dedicated 20 amp circuit.
 

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Do you envisage any further expansion of the garage ?
Or are you happy with what you have ?
You don't even need 60A
40 would be enough !
20A for saw and another 20 for rest.
 

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Discussion Starter #5
Is the garage attached or detached? How far from the main panel? How many empty slots do you have remaining?

If the saw has a plug in 120 volt motor, the max receptacle you can have is 20 amp. Perhaps you are plugging it into a circuit with other items using power at the same time. If so you need a dedicated 20 amp circuit.
It's an attached garage and the sub panel would be approximately 20 feet from the main panel. The main panel is brand new and has 20 spaces. I have more than half available.

The saw can be run in 120 and 240 configurations. I'm currently running it at 120 since I don't have 240 in the garage. I'm assuming if I run the saw at 240, I'm going to need less amps. Even if I run the saw on 120 with nothing else on the circuit, I can trip the breaker if I'm cutting very hard material with a somewhat dull blade but that's besides the point. I'm going to run it in the 240 configuration once the sub panel is installed.
 

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JOATMON
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As a classic DIY woodworker...and also in LA

You don't need heat or AC

30A 240 will be more than enough.

Assume worse case....
240V compressor running while your running a table saw and dust collector.

If it was me, I'd slap in a 50A 2-pole breaker to feed your sub-panel. Use a 6-slot sub...one double for the compressor....then single breakers for the rest of the stuff. Unless you think you might want to add a 240Vac mig welder later. Then just give yourself a 240 twist lock connector somewhere with it's own breaker.

Click on the link in my signature for more details about my garage.
 

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A "Handy Husband"
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20 feet? Why bother with a sub panel, just run the circuits back to the main since you have plenty of slots.
 

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Discussion Starter #8
As a classic DIY woodworker...and also in LA

You don't need heat or AC

30A 240 will be more than enough.

Assume worse case....
240V compressor running while your running a table saw and dust collector.

If it was me, I'd slap in a 50A 2-pole breaker to feed your sub-panel. Use a 6-slot sub...one double for the compressor....then single breakers for the rest of the stuff. Unless you think you might want to add a 240Vac mig welder later. Then just give yourself a 240 twist lock connector somewhere with it's own breaker.

Click on the link in my signature for more details about my garage.
Great info. Much appreciated. I do plan on welding at some point and may want to run more circuits so I'll go with a panel with more spaces as cost in the panels are very insignificant and I have plenty of wall space...
 

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Discussion Starter #9
20 feet? Why bother with a sub panel, just run the circuits back to the main since you have plenty of slots.
I may have underestimated a little, it's probably closer to 30 to 40 feet. I suppose I could. I just figured it may make it easier to run more circuits in the garage at the later point, would give me a more convenient way to shut off power to the shop and leave space in my main panel for future additions such as solar and remodels...
 

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JOATMON
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I may have underestimated a little, it's probably closer to 30 to 40 feet. I suppose I could. I just figured it may make it easier to run more circuits in the garage at the later point, would give me a more convenient way to shut off power to the shop and leave space in my main panel for future additions such as solar and remodels...
Exactly the reason. Especially when you trip that breaker by accident.
 

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JOATMON
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Unless you plan on doing a lot more than currently, I'd run one 20 amp back to the main.
The cost difference between 20A vs 50A is minimal. Labor is the same. Want to run a compressor, dust collector and table saw at the same time on 20A? Nope.
 

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The cost difference between 20A vs 50A is minimal. Labor is the same. Want to run a compressor, dust collector and table saw at the same time on 20A? Nope.
I am all for subs and future-proofing, but nothing in the OP about running a compressor, table saw and dc at the same time on the same circuit, or added machinery. It's just his table saw giving him trips. Add a dedicated one for his saw and jointer use, rest operate fine on existing.
 
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