DIY Home Improvement Forum banner

1 - 20 of 34 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
I am looking to run power 130 feet with 10 gauge 3 wire. The breaker box in my shop is a recycled 150 amp main breaker box. Can I put a double pole 30 amp breaker in the breaker box in the garage and connect the whit and black wires to the terminals of it and connect the ground wire to the ground bar. Then in my shop I can connect the white and black wires to the top holes on the main 150 amp breaker and the ground wire to the ground bar. Would that work and is it safe? Then would I have 240 volts at my shop corect?
 

·
Super Moderator
Joined
·
13,889 Posts
Your need a 4 wire feed to the outbuilding. Two hots, a neutral and a ground.

The #10 will be too small to terminate on the lugs of a 100 amp breaker.

You will also need a grounding system at the outbuilding.
 

·
Registered
Joined
·
1,000 Posts
I am looking to run power 130 feet with 10 gauge 3 wire. The breaker box in my shop is a recycled 150 amp main breaker box. Can I put a double pole 30 amp breaker in the breaker box in the garage and connect the whit and black wires to the terminals of it and connect the ground wire to the ground bar. Then in my shop I can connect the white and black wires to the top holes on the main 150 amp breaker and the ground wire to the ground bar. Would that work and is it safe? Then would I have 240 volts at my shop corect?
As, ou planned using black and red + white on the neutral bar.

Are you saying 10/2 + ground? You must
How would I wire it with 4 wires?
have a neutral.
 

·
Registered
Joined
·
2,060 Posts
If the cable goes outside, it can't be NM-B (Romex, would be orange) cable. It must be UF-B (gray) cable.

Yes, it depends what you mean by "3-wire". The correct wire is called "/3" but it has 3 active conductors plus a ground wire so 4 really. That is fine. However if you mean literally 3 wire as in black white bare, then you can only run 120V on that. Can't use bare as a neutral.

Neutral and ground must be kept totally separate in the subpanel. Any neutral-ground bonding straps or screws must be removed. You'll need to install an accessory ground bar. The panel label should list the ground bar models that it has screw holes already punched for.



Yes, you can use an old 150A panel. On a subpanel, the main breaker is only there to a be a disconnect switch, nobody cares what number is on it. And even that is only required in outbuildings.
 

·
Registered
Joined
·
66 Posts
Aluminum SER 6-6-6-6 will cost you about the same or less than UF 10/3 with ground and supports 50 amps.

The 50 amp breaker will cost about the same as a 30 but it still may not be big enough for the 150 amp main breaker. Square D takes a minimum of 4 gauge.

If fact Home Depot has 150’ of 6-6-6-6 SER at ft.


Sent from my iPhone using Tapatalk
 

·
A "Handy Husband"
Joined
·
12,329 Posts
At 130 feet, I assume the shop is a detached building. How are you getting there? Underground? In the air?

Sent from my Lenovo TB-X606F using Tapatalk
 
  • Like
Reactions: mark_kershner

·
Registered
Joined
·
9,211 Posts
I would go with the 50 amp cable unless a crystal ball indicated the 30 amp (10 gauge) cable would be adequate for several years.

Since digging a trench is such a big undertaking, it is better to plan more electrical capacity now in case you need it later.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #9
I have already buried 2'' conduit to get to my shop. I will take some pictures of my shop bracker box today to.
 

·
Registered
Joined
·
9,211 Posts
With underground conduit you can choose and easily upgrade any wet location rated wiring, single conductor (typically red, black, white, green THWN) are preferred.

Note: If you choose to start off with a 120 volt only white black green #10 THWN or UF 10/2 Romex then you may experience degraded performance of tools due to voltage drop over 130 feet panel to panel and usage more than 20 amps. The 4 wire 10 gauge 120/240 volt run with the usage somewhat if not perfectly balanced across the two 120 volt legs will carry the full 30 amps per leg without excessive voltage drop (over 3 percent).
 

·
Super Moderator
Joined
·
13,889 Posts
SER cable cannot be buried.

In conduit it is much easier to use individual conductors.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #16
There is a ice dam in my conduit so I cant push it through untill spring so I want a wire that I can string in the air until spring.
 

·
Red Seal Electrician
Joined
·
431 Posts
What are you trying to run at the shop? As already stated, you won't get 30A on #10 at that distance. If that's ok, I'd look at a length (or roll) of #10/4 cord to use as a temporary feed until your conduit thaws. After that, you can sell or re-purpose the cord.

Aerial span is going to need neutral supported (triplex/quadplex) cable... and #6 is likely the smallest you can get. Seems like a bit of a job to get that set up for just a couple months use.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #18
I need to run a 240 volt welder that pulls a 27 amps at max output. Pus lights and fume sucker.
 

·
Red Seal Electrician
Joined
·
431 Posts
I need to run a 240 volt welder that pulls a 27 amps at max output. Pus lights and fume sucker.
You might get by with #10/3 minimally - depending how hard you need to work the machine. Try your machine with and without the cord and compare the performance.

Without the extra conductor, you can't have both 120 and 240v. Some LEDs can work on 100-250V... not sure about your fume sucker.

The biggest cheapest cord I ever got was from a marina... #8 SJTW for boat hookups than had damaged twist-lock connectors. Lopped the ends off and hardwired in JBs. Ran my shop off those for a couple years.
 
1 - 20 of 34 Posts
Top