I’ve been lurking here for some time and have picked up lots of useful information, but this is my first post. We recently moved into a new house where I plan on turning the garage into a shop. The space is ideal for a shop with 980 sq feet of space and 11 ½ foot ceilings. The garage already has all the 110V circuits and outlets I could need along with ample lighting (12 four foot, four bulb, fluorescent fixtures). The only thing I need to add is 220V power to feed a variety of machines. The garage is already insulated and the walls are covered with sheet rock and painted. My plan is to add a surface mounted 125AMP subpanel and run all the new 220 circuits off of it. I will run the cable through either flexible metal conduit or EMT. I would like to run separate circuits for each 220V outlet so I can run several machines simultaneously. I plan on running a mixture of 12/2 and 10/2 wire depending on the expected load (20amps and lower will be run with 12 gauge anything higher will be run with 10 gauge). I would like to do the wiring myself then pay an electrician to come in and inspect my work prior to connecting the subpanel to the main panel. I’ve done minor wiring throughout the house, but nothing on this scale.
I have a couple of couple of questions that I’m hoping my fellow creekers can help me with so I can complete the first draft of the electrical design. This isn’t all the questions I have, but it is what I need to know to get started. Once the basic design is completed, I’ll post it for review along with what I’m sure will be more questions.
1.Can multiple 220 circuits be run through the same piece of conduit (up to the NEC limit for the number of wires in a certain size conduit) or does each circuit need to be run in its own conduit?
2.If multiple circuits can be run through a single conduit, can they share the same ground wire?
3.Does the conduit need to be grounded?
4.I know all the machines just need two hot wires and a ground, is the same true for the dust collector and compressor?
5.If multiple circuits can be run through the same conduit, can I mix 10 and 12 gauge wires in the same conduit provided I don’t exceed the NEC limit on number and size of wires for the size of the conduit?
Here is a list of the 220V circuits I plan to run.
Table Saw
10" Unisaw
1.5HP 230V 9.6A
Clearvue Cyclone Dust Collector
5HP 230V 20.8A
15” Planer
3HP 220V 18A
8” Jointer
3HP 220V 15A
Ingersoll Rand Compressor
(not sure about the HP) 230V 15A
18” Bandsaw
4.5HP 220V 30A
For future Use
3HP 220V 18A
Also included is a copy of the shop layout.