Running electric to shop

[bondkx01]

I have a 30x30 shop on the back of my property that once had 220 running to it but after I had my overhead lines and a panel move, the line was too short and not in a spot I'd want a junction box to pop out of the ground. So now I'm looking to run new power out there but enough to support my welder, phase converter for 3 phase compressor and at least one dedicated 20 amp 110 for ginders and such. The run is about 200' from the house panel and I'll have to trench at least 2' I believe the code is. Any way, here's my question as my eletrical guy is MIA...with the intent to power 2 220 requirments and the 20 amp 110, do I need to have dedicated runs for each or is there another way to do this where I can just do a single large gauge run to a sub panel in the shop and branch from there?

Thanks for the help!
Ken

 

[PAToyota]

I can just do a single large gauge run to a sub panel in the shop and branch from there?

Yep. That would be the way to do it.

 

[bondkx01]

Yep. That would be the way to do it.

Thanks PA. I also put a post out on "doityourself" and got some good insight. In short, need to add up all the amperage I'll need to identify the conductor size and breaker in the main panel size. I'll post back once I get this all figured out for others benefit.

thanks!
Ken

 

[PAToyota]

Personally, my answer was to get a C320 (400amp) service drop to the house that feeds a 200amp panel in the basement and a 200amp panel in the workshop.

 

[Toyo FJ40]

Personally, my answer was to get a C320 (400amp) service drop to the house that feeds a 200amp panel in the basement and a 200amp panel in the workshop.

I did the same thing when I put in my shop. Upgraded the meter box to 400 amp and ran 200 to the house and 200 to the shop. You should run more than you need because you don't want to have to redo it if you buy a new welder or something.

 

[LandCruiserPhil]

200amps????
One guy would be very hard pressed to use 100amp at any given time.
200A = 3-3/0cu is running about $15/ft x 200' $3000

Back to your question- you need a sub panel, 100A max if it was me.

 

[PAToyota]

200amps????
One guy would be very hard pressed to use 100amp at any given time.

The Syncrowave 250DX and water cooler alone is on a 100amp breaker. The Powermax 1100 plasma is on a 60amp breaker, compressor is on a 30amp breaker, air dryer is on a 20amp breaker, and the plasma table is on a 20amp breaker. Add in some lights and other stuff...

Love how people always start to say "One person doesn't need any more than..."

 

[LandCruiserPhil]

The Syncrowave 250DX and water cooler alone is on a 100amp breaker. The Powermax 1100 plasma is on a 60amp breaker, compressor is on a 30amp breaker, air dryer is on a 20amp breaker, and the plasma table is on a 20amp breaker. Add in some lights and other stuff...

Love how people always start to say "One person doesn't need any more than..."

Pretty harsh

Who are you quoting?

Breaker sizes are not actual loads.

T...... In short, need to add up all the amperage I'll need to identify the conductor size and breaker in the main panel size.......
thanks!
Ken

This^^^no reason to spend more then you will need.

 

[PAToyota]

Pretty harsh

Who are you quoting?

Breaker sizes are not actual loads.

Not trying to be harsh. You made a blanket statement that one person would be hard pressed to use 200amps in a shop. I explained my own use.

Yes, I know that breakers are not the same as loads. But I can assure you that I would not get by with just a 100amp service to my workshop.

 

[LandCruiserPhil]

Not trying to be harsh. You made a blanket statement that one person would be hard pressed to use 200amps in a shop. I explained my own use.

Yes, I know that breakers are not the same as loads. But I can assure you that I would not get by with just a 100amp service to my workshop.

There are always exception to everything .... YOUR usage is not the norm.

 

[LAMBCRUSHER]

are all of the circuits you need in the existing too short run? is it an in-ground run? If so, then why not just christy and polaris splices? Not ideal, yeah, but hey, if it'll work...and if it won't, then I'd say 100 subpanel at the shop, oversize the wire and conduit to overcome voltage drop. what size is your Mains Breaker?

christy box= inground concrete box of various dimensions and weight ratings, some of which are traffic rated.....bury that sucker

 

[PAToyota]

There are always exception to everything .... YOUR usage is not the norm.

And you say that I was harsh...

I can point to quite a few people who have similar setups to mine.

 

[cody c]

There are always exception to everything .... YOUR usage is not the norm.

If the OP has alot of lighting, electric heating or AC, and a big air compressor, a decent amount of current can be used up before using some of the big equipment PAtoyota mentioned.

Having said that, we're shooting in the dark as to what the OP's power requirements are unless he elaborates what equipment he plans.

On the other hand, a 200' run of overhead or (Id prefer underground) cabling will obviously need to be oversized for voltage drop. Having a 200 amp panel and cabling to support that may be nice to lessen voltage drop, which will be easier on high inertia motors like compressors or bench grinders, so I see benefit in having a larger panel.

But once he sees what 240' of 4/0 or 250 teck cable costs he may consider the 100 amp panel. I guess you can use aluminum to save a few bucks but there is some tricks to it...

 

[LandCruiserPhil]

The OP is smart one here by doing a load calc to determine his needs. The goal is to provide enough power to meet his demands without spending money unnecessarily.

To answer the OP main question, we all can agree he needs a sub panel at the garage.

 

[PAToyota]

I agree it would help greatly to know the proposed usage the OP is planning for. But sometimes it helps to think beyond what you might think you need at this moment.

I built my shop in '97 - before the internet was developed to the point we are at now. I was on one off-road mailing list at the time, but people really weren't talking about garages and shops anywhere that I had found. I did my best to plan ahead for my needs and cover my bases, but the one thing I really missed out on was room for a lift. I briefly considered a pit, but ran into the issues with ventilation and insurance and stopped there. At the time, I really thought a lift was a commercial shop thing and never even considered that people might put one in a personal shop. I have 10' ceilings, but you're talking more like 12' for a lift. If someone had said to me at the time "Hey, a commercial lift can be had for $2000 to $3000 dollars, you might want to go with 12' ceilings just in case..." I'd have been eternally grateful.

So I threw my C320 setup out there just to say what I did. ToyoFJ40 chimed in and said he did one too. Then someone said that was overkill...

Just by being on this forum I'd say that quite a few of us went flying past "normal" some time ago... How many "normal" people are out there fabricating off-road rigs in their home shops? When I built my shop I was told by many that anything more than maybe a circuit for lights and two circuits for outlets for a "garage" was overkill. A 220V circuit for a welder? What? There are houses on my street that still only have 60amp service FOR THE WHOLE HOUSE!

In the past five years, I've seen more and more people going to the C320 setup for shops - even with the spike in copper costs. Heck, I've been seeing an increase in C320 dual panel setups just for high end houses when they start putting in multi-zone heatpump systems, home theatres, and such.

 

[Toyo FJ40]

I ran aluminum underground in conduit to the shop and I have a Syncrowave 300 and a mig both on their own plugs. I wanted to be able to put an apartment over the shop in the future which will have it's own 100 sub panel.

The service upgrade, new panel in the house , 150 run to shop , outdoor disconnect at meter box for shop and panel in shop cost $5800 installed. Pricey but I think it was worth it.

 

[Azca]

Okay, as one with extensive experience in the electrical field I tend to agree that 100 amps, for a garage only, is more than most of us will ever need to supply our equipment. That said, we need to know what the equipment is in the garage and more importantly, what equipment will be running simultaneously. That is the key here, you do not need to have a feeder large enough to feed everything at once. So to figure it out do the following:

Largest motor at 125%, plus lighting at 125%, plus any 120 volt loads that run continuously (3 or more hours non stop) such as fans or an evap cooler. Then add the remaining loads, again that are being used at the same time, at 100%. This would include heaters etc.

Note that the National Electrical Code, for a residential garage, does not require additional loads to be added to the load calc for lighting, receptacles etc. It does require that you add any specific loads (air compressor etc) for the calc.

If you would like you can then add a cushion (125% is more than enough) to accommodate what if's and future loads. (don't forget the beer cooler).

You said you have a 200 foot run, the voltage drop will need to be taken into account for your wire size. Too small a wire will not only make your motors work harder at start up (shortening their life) it will also impact your utility bill due to higher resistance(ignore the utility bill if you don't work in their 5 days a week.)

You are currently allowed a single feeder or branch circuit to a structure. You need to have a main (up to six moves of the hand in the panel is okay but I don't recommend this) and you need two ground rods (min 6 feet apart, further apart the better) and water bond if water is at the garage.

If you have specific questions you can PM me if you would like or post here so everyone can share.

 

[45Kevin]

When I ran power to a detached garage several years ago I used plastic conduit and ran seperate wires in it. The seperate wires worked out cheaper, and could be replaced without future excavation.

In the same trench, run another couduit for phone, cable etc. Make sure the conduits are seperated by several inches to reduce interferance.