New shop wiring time?

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blaser.306

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As the title would suggest , my new shop is up and the trades are hovering! I have to ask a "loaded question" I understand that there are many variables... I currently do not own any 220 V machines, But that will change. I am having 220 single phase power pulled into my building. My question is what amperage breaker are 2 hp single phase motors running so I have a starting point for the electrician when he is here . Thanks an advance.
 
2HP doesn't really tell you how much current, which is what you want for sizing wires and breakers.

It looks like about 9A for 220V. I ran all of mine with 12 gauge and 20A breakers. Mostly so I could use the same wire and not have to buy different sizes. The connectors at the end need to match as well.

I already had some higher amp connections for the welder and compressor. I would suggest a clothing dryer 4 wire outlet on a couple of walls for loads like those. Common with easy to get plugs, and good for 40A if I remember right.
 
That will give me a starting point. I can always change it later if need be, I found out that the federal pacific panel in my basement is obsolete so apparently now I also need to replace the main panel so I can add the garage circuit. Ah, the joy of construction...
 
My previous place had a total of one 15 amp circuit for a large 2 car garage, including lighting. Useless for shop space.

When I wired my current workshop, I ran two circuits of 20amp (12ga) with outlets i pairs, one to each circuit. I also ran two 20 amp 120 circuits, again outlets paired. This way I can balance stuff across outlets later on. Also one 50amp circuit, with one outlet on each wall except where the garage door hangs. Each circuit goes from the breaker panel to a large junction box in the ceiling, from there it stars out to the outlets. The attic is accessible so adding an outlet is just another drop from the ceiling.

Those are my general machine tool circuits. There are separate circuits, 15 amps for lighting, 15 amps for the gas heater and dehumidifier, and a dedicated 220 circuit for the air compressor. I did all this after insulating but before sheetrock on the walls.

20 amps at 220v wll run up to 3hp, including a vfd driving a 3phase 3HP motor. 50amp circuits for welders.
 
1 HP = ~750 watts.
(P)ower = I (current) x E (volts).

2 HP is ~1500 watts. 1500 watts / 220 volts = 6.8 Amps.
 
Go back to your main electrical panel where the meter is. Figure out what the largest size circuit breaker you can add.
Run wire from that breaker to your shop and have a sub panel installed. Now you can add as many 220 or 110 circuits as you desire.
I was able to fit a 220volt 70 amp breaker for my shop.
 
The subpanel is a good idea. I added a 100 amp panel to allow for easy changes
 
I am running a 60 amp sub panel into the shop with 2 220 V outlets as well as several 15A circuits with all the needed lighting etc. As I mentioned I just wanted a good jumping off point to tell the electrician when he is here. Getting excited about the new space!
 
blaser.306 said:
I am running a 60 amp sub panel into the shop with 2 220 V outlets as well as several 15A circuits with all the needed lighting etc. As I mentioned I just wanted a good jumping off point to tell the electrician when he is here. Getting excited about the new space!
Click to expand...
Congrats on the new space! I wired my shop with 15A 110's for lighting and 20A 110's for power around the shop. Looking forward to seeing your shop photos.

Bruce
 
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