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Putting up a new workshop. Power questions.

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Sticks McGee

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Putting up a new workshop behind my house. 16x24. Main panel is in the garage. It will be about a 40 ft. run. There is wiring going to a point on the deck for an old hot tub. I will pull that 50 amp 240 bolt breaker to feed sub panel in the workshop. I’m thinking 60 amp is plenty to feed it. It’s just me. A hobby wood shop. I figure I can run pvc from the panel location to within about 4’ from the new building. Can I run in pcv in conduit attached to joists of my deck over to the point of coming out and dropping into the ground 4’ over to the building. House built in 1996. 200 amp service to the house. What is the best wire choice to run between main panel and sub panel?
 
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AntonLargiader

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That's way too big. You are doing just about exactly what I did, and I used #6 TWHN in 3/4" PVC conduit. Use 1" to make it easier.

Similar threads abound:

Upgrading Electrical Service to Detached Garage

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Sticks McGee

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Trail Creek, IN
AntonLargiader said:
That's way too big. You are doing just about exactly what I did, and I used #6 TWHN in 3/4" PVC conduit. Use 1" to make it easier.

Similar threads abound:

Upgrading Electrical Service to Detached Garage

I'm looking for some help to learn the right way to upgrade the power going out to my detached garage. Currently I have a 25x25 2-bay garage with power fed from what appears to be a single 15A breaker in the house. There is no sub-panel in the garage, just a handful of lights and outlets. I'd...
www.garagejournal.com www.garagejournal.com

Sizing new power feed to small garage

I'm replacing the old (long gone) underground power to an 18x18 detached garage. It's not a shop; it's just parking although I do want a 240 outlet for whatever comes up. Basically lights (maybe 200W total) and a few outlets. I occasionally use a portable air compressor out there, and the car's...
www.garagejournal.com www.garagejournal.com
Click to expand...
So what size breaker in your main panel to feed the sub panel? Did you run 4 conductors? Hot, Hot, Neutral, Ground?
 
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dcg9381

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Sticks McGee said:
Putting up a new workshop behind my house. 16x24. Main panel is in the garage. It will be about a 40 ft. run. There is wiring going to a point on the deck for an old hot tub.
Click to expand...
Does that wiring have a breaker on it? The "usual" wiring for hottubs is 240V @50A, but some are smaller. If modern, there will be a GFI breaker in place somewhere.


Sticks McGee said:
I will pull that 50 amp 240 bolt breaker to feed sub panel in the workshop. I’m thinking 60 amp is plenty to feed it. It’s just me. A hobby wood shop. I figure I can run pvc from the panel location to within about 4’ from the new building. Can I run in pcv in conduit attached to joists of my deck over to the point of coming out and dropping into the ground 4’ over to the building. House built in 1996. 200 amp service to the house. What is the best wire choice to run between main panel and sub panel?
Click to expand...
If you have an exterior grade panel or breaker you can connect to, sure, just run electrical PVC conduit out to the shop. Technically you can get 6/3 through 3/4" PVC, but I can tell you it's a heck of a lot easier to do it in 1" conduit. As you work with the conduit, install a pull string (or vacuum one through). 50-60A is more then enough power for a building that size IMHO.
 
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Sticks McGee

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dcg9381 said:
Does that wiring have a breaker on it? The "usual" wiring for hottubs is 240V @50A, but some are smaller. If modern, there will be a GFI breaker in place somewhere.



If you have an exterior grade panel or breaker you can connect to, sure, just run electrical PVC conduit out to the shop. Technically you can get 6/3 through 3/4" PVC, but I can tell you it's a heck of a lot easier to do it in 1" conduit. As you work with the conduit, install a pull string (or vacuum one through). 50-60A is more then enough power for a building that size IMHO.
Click to expand...
I believe the breaker for the hot tub is a 50a 240v. I would have to look. The cable that used to come out of the hole in the deck is like a Romex cable. It’s now laying on the ground under the deck. The deck is too low to crawl under. I plan to remove all the decking and re deck it. I took about half the deck off to make room for the shop. I figured I would run two 120v 20 amp circuits for wall outlets and one 120v 15 amp circuit for lighting. I want to add at least one 240v circuit for future use. I don’t have any 240v tools currently.
 
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dcg9381

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Sticks McGee said:
Something like this panel to put in the new building?
Click to expand...
Yes, once you get the sub panel feel in, you can wire that building any way you want. Make sure there is no neutral ground bond in the panel. One feed to the building. FYI - as it's an "outbuilding" it may need a ground rod.
 
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Sticks McGee

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Thank you. I read thru the whole thing. This is what I understand: (2) #6 black for the hots. (1) #6 white for the neutral. (1) #4 green for the ground. I may put larger conduit Incase I decide to upsize later. Maybe 1.5”. 60a 2 pole breaker in main to feed sub. Sub panel cannot have neutral and ground connected (remove bonding screw if present) add a grounding bar inside the sub panel. An additional bare copper ground will run out of the sub panel to outside and connect two grounding electrodes (copper) 8’ into the ground. 6’ apart. If the sub panel has a main it basically will act as a disconnect as the 60a breaker in the main is the protection for the sub.
 
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dcg9381

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Sticks McGee said:
Thank you. I read thru the whole thing. This is what I understand: (2) #6 black for the hots. (1) #6 white for the neutral. (1) #4 green for the ground. I may put larger conduit Incase I decide to upsize later. Maybe 1.5”. 60a 2 pole breaker in main to feed sub. Sub panel cannot have neutral and ground connected (remove bonding screw if present) add a grounding bar inside the sub panel. An additional bare copper ground will run out of the sub panel to outside and connect two grounding electrodes (copper) 8’ into the ground. 6’ apart. If the sub panel has a main it basically will act as a disconnect as the 60a breaker in the main is the protection for the sub.
Click to expand...
I think you've got it.
I question the need for a larger #4 ground. #4 is larger diameter than #6.
 
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Sticks McGee

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Yes I misread. I see the ground can be downsized to a #8. Thanks for the link. I had actually searched and found that thread but I did not read it all the way to the end.
 
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Sticks McGee

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BillK said:
If you are going to do that you might as well do it all right now. The difference in price will be very little. For what its worth I did a 100 amp sub when I built my detached garage.
Click to expand...
What wire did you pull for that? I’m not opposed. The building goes up next week. Just been rolling it around in my head.
 
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dcg9381

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Sticks McGee said:
Would stepping up to #4 for hots and neutral and #6 for ground get me 80 amps? My run will be probably 40 ft.
Click to expand...
Here you go:
www.cerrowire.com

Cerrowire Resources - Ampacity Charts

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. Cerrowire's ampacity chart helps calculate the load requirement for a circuit.
www.cerrowire.com www.cerrowire.com

IMHO 50-60A is more than enough for your space.. I've got a much larger shop with 2 HVACs, EV charger, etc and it's fed via 90A.
 
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Sticks McGee

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Trail Creek, IN
dcg9381 said:
Here you go:
www.cerrowire.com

Cerrowire Resources - Ampacity Charts

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. Cerrowire's ampacity chart helps calculate the load requirement for a circuit.
www.cerrowire.com www.cerrowire.com

IMHO 50-60A is more than enough for your space.. I've got a much larger shop with 2 HVACs, EV charger, etc and it's fed via 90A.
Click to expand...
Thank you.
 
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BillK

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Sticks McGee said:
What wire did you pull for that? I’m not opposed. The building goes up next week. Just been rolling it around in my head.
Click to expand...
Dont remember for sure but I can look. It was 30 years ago :) I do know it was copper. Runs through conduit for about 30 feet above ground along the house then down and underground for about 50ft. Whatever I used passed inspection. Ill try to remember and look at the paperwork this weekend.

I am glad i used the larger wire and panel. I am getting ready to put heat and AC of some type in and I know I have the capacity to do whatever I want.
 
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Max

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Depending on what you're doing 60A should be good for a single person woodshop. This assumes that you do not have really large equipment, like 20" planers or 16" jointers. If you do you should do a load calculation to make sure that you're ok.

My 60A feeds a Unisaw, a 3 HP dust collector, a minisplit, misc stuff (stereo, batt chargers) and a dehumidifier all at once. Lights are on a different circuit but low power anyway. And other stuff - router table, jointer, planer, track saw, etc all pull less than the unisaw.
 
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Sticks McGee

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Hand power tools, grizzly contractors table saw (25 years old). Router table. Dewalt 12.5” planer. Small drill press. No jointer yet. No dust collection yet. Will heat it with a gas hanging furnace. Plan to do LED lighting. It will be a hobby workshop.
 
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Max

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60A will be more than enough. Having said that, I am the kind of guy that’d use larger conduit just in case. And I’d run a second conduit out there for low voltage stuff like ethernet.
 
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BillK

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Sticks McGee said:
What wire did you pull for that? I’m not opposed. The building goes up next week. Just been rolling it around in my head.
Click to expand...
Well I looked through all of my papers but for some reason I dont have any of the electrical stuff in the folder :( It was interesting to see some of the other prices. My 24 ft trusses were $26 each :) Ill look some more this week, or if I get energetic I will pull the cover off the panel and look.
 
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inphx

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.. and a third conduit back from the out building in case you ever put solar panels on it and want to find a way back to the house or garage to charge cars...
 
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dscheidt

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Sticks McGee said:
Something like this panel to put in the new building?
Click to expand...
You need a disconnect. So either a main breaker panel, or you have to back feed it. A main breaker panel is easier and probably cheaper. Don't go that small, there's little reason not use something with at least 20 spaces. The cost savings of something smaller are minor, but the cost of expanding it when you realize you need more space is very high, and you're described load gets it very nearly full before you expand. (The cost of the bigger panel may actually be negative: when I put a sub in my garage, I could get a main breaker panel for less than a smaller main lug one and the necessary breaker, becasue lots more people buy main breaker panels than main lug ones.)
 
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Sticks McGee

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They are getting started today.
 

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dcg9381

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Sticks McGee said:
How is that stuff to pull thru conduit? I looked at some on a spool the other day at Lowe’s and it seems like it would be very difficult to work with. If it’s easy to work with I would go that route.
Click to expand...
It pulls fine through 2" or larger. Run a pull string first, use cable lube. 2 man job, one pushing, one pulling... a 40' run I could probably do myself.
 
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dcg9381

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You'll need to be more specific about what it is and gauge (I can guess). Places like Southwire give diameter. In "general" pulling aluminum wire that can handle 90 amps can be done in 2" conduit (straight shots are easy). You can always do 2.5".

If you lay the conduit in first, you can tie a plastic grocery bag on the end of a pull string and **** it through. You use this as a "pull wire". Just lube the cable as it goes in. Having a helper makes it much easier and 40' with one or two 90s is no big deal at all.
 
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mm08822

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For a 90 feeder, you can run 1-1/4" with 2-#2, 1-#4, Blacks, and 1-#6 Green Aluminum XHHW individual straight conductors. It will go through easily.
MHF is spiralled and takes up a little more room and more pulling effort. Same for URD.
1-1/2" could be used but 2" is a waste.
The extra splices required for URD usage doesn't make it a good option IMO.
 
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