220 electric help

[poppa]

Hi all , Want to run 220 to my attached garage. Thinking about a 60 amp in main to sub panel in garage with a couple extra 110 circuits. Thinking of using 6 gauge to garage and 220 outlet. Sound ok?? Suggestions?? Thanks

[Gold Rush]

The chart I just looked at say 37 amps max for power transmission through 6 gauge wire.  For 60 amps you'd need to run 4 gauge.  That being said: I ran 6 gauge in 1991 when I retired from the Air Force to the back shop I built (maybe 35 feet) and have never had any issue.  I run 240 volt welder and air compressor.  Also have many outlets and a window air conditioner.  I have both hot lines on 50 amp breakers...

[Paul G]

The distance from the main panel to the sub panel and sometimes temperature, must also be considered to determine proper wire size. This online calculator says that for 60 amp service. copper wire, in raceway (conduit), no longer than 60', 4 gauge is good.  If the run is longer than 60', you need to upsize the wire.

http://wiresizecalculator.net/

[alfaitalia]

Side question:.....just curious but is your mains power voltage 220 volts in the US? Don't know why but I've always assumed it was 110v...like in parts of mainland Europe although is getting less common there now. We have 240v.....which is actually now about 230...was lowered slightly a few years back to save power and take a little strain of the National Grid.

[Paul G]

Side question:.....just curious but is your mains power voltage 220 volts in the US? Don't know why but I've always assumed it was 110v...like in parts of mainland Europe although is getting less common there now. We have 240v.....which is actually now about 230...was lowered slightly a few years back to save power and take a little strain of the National Grid.

The power we bring to our residential service panel is 240 volt single phase with neutral. From our 240 volt phase to phase, we can get 120 volt phase to neutral. The 120 volt power is what our wall outlets will have, all of our small appliances run on this voltage. Larger appliances such as an electric dryer, oven, cook top, air conditioner, etc. will use the 240 volt.

The real number if measured with a DVM may range from 220 to 240 volt phase to phase depending on the demand and time of day. And then maybe 115 volt to 120 volt phase to neutral. Some commercial lighting and other applications may use 208 volts. That is only in office buildings and some industry. Not residential.  

[poppa]

Thanks for the quick replies.

The plan is , 220 - one circuit for both air compressor and welder ,have never used both at the same time. And maybe 4 or 5 120 future circuits. Wife wants an outlet in front (outside) , maybe an air conditioner in garage next summer , one for 3 or 4 lights for in the attic of the garage when insulation/drywall are done , and a garage heater. There are already outlets and lights. Welder says 19.5 amps and compressor says 12.5 @ 220v. Would a 30 amp in garage and 60 amp at main be good for this?? I should have started this with this info. Thanks

[Gold Rush]

I expect you intend to run 10/3 with ground from the breaker box to both the welder and air compressor.  When it comes to internal wiring I believe more is better.  You can use 12/2 with ground for the outlets and lights.

I'd put 50 amp breakers in your main box then use 40 amp breakers for the shop 240 legs and 20 or 25 amp for the lights/outlets.  That is the max each wire size is capable of carrying.  If you do develop excess current those breakers would trip before the wire would toast.

[poppa]

Gold Rush , do you agree with Paul , I should use 4 from house to garage? Paul did not have this info , it would probably be 25 ft , max.

[Gold Rush]

It would not hurt but I really don't think you'd see any immediate benefit.  Unless you start adding some serious current load like a big a/c unit or electric heater.  Your welder, air compressor. and a few plug in things won't overload the 37 amp 6 gauge rating only 25 feet away from the source box.  That being said:  Remember what I said about more is better.....   Since you are starting from scratch, why not go a bit bigger than you need now.  Allows for expansion..  If you do then you can go with your original 60 amp breakers in the main box to feed the shop.  I'd still stay with my previous recommendation in the shop breaker box.

[Nacho-RT74]

In Venezuela on residential areas when we need 220V just use two 110V hot lines instead one line and neutral. That gives around 208V ( due the phasing sum wich is 120 degrees off )

The kitchen at home is working like that in fact

208-220V like this ( combining two 110V  lines ) with 30-40 amps load  can be handled by 6 guage, since the load is shared between both lines. Even 8 gauge if a really short distance

[poppa]

I picked up my wire this weekend and when I got home it was not solid. I thought that is what I needed , I am right or is this ok???

[Paul G]

Solid is 12 AWG and below for residential wiring. Your wire should be stranded. Solid does come in larger sizes but only used for equipment grounding.

[poppa]

Doing 220v from main panel to sub panel in garage.

[John_Kunkel]

For residential use, any insulated wire over 10-gauge will be stranded.