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20A circuit or 60 sub?

Bean438

Member
Joined
May 1, 2018
Messages
22
Hello.

My attached garage has 15A plugs, and one 30A for a construction heater.

Garage is used to park cars, snowblower, etc. no welding, woodworking. Mainly car washing, and the odd brake job or minor maintenance stuff. (Brakes never need replacing in July, always January -40 thus the construction heater. )

I have a new power washer that requires a 20A circuit, so what would you do?

1. Replace existing 10g wire with a 6g and instal subpanel
2. Just run a new 20A circuit on some 12g
3. Instal 30A sub panel with existing 10g

Option 1 makes most sense, but overkill for what I need, although cost would be offset by shorter 20A circuit run.

Option 2 is really what I need.

Not sure if option 3 is code or not. I’d just have to connect the neutral. Construction heater and power washer would never be used at the same time.

It’s looking like option 1 or 2. Option 3 was simply because the wire is there
 
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rlitman

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Oct 18, 2010
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Location
Long Island
How difficult is pulling a new line? Do you plan to make it more difficult in the future?
Do you think you will ever need more power for something else?

Option 3 is only ok if you have 4 wires behind that plug. If you don't have a neutral AND separate ground, forget that option.
 
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Bean438

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May 1, 2018
Messages
22
Not difficult to pull a new line. Remove existing 10 gauge, wouldn’t even have to drill. Let’s say half hour tops. In future it will be no more difficult.

I dont think I’ll need more power BUT I said the same thing 15 years ago when the electrician installed the construction heater outlet. Had I installed a sub panel back then we’d not be having this discussion.

I do want to add additional lighting. I only have 2 led bulbs. Lights don’t,draw much so I think the existing circuit will be fine.

Current construction Heater outlet is a 10 g wire, black, red, white, and copper ground. Only the red and black are connected. Whites are capped off.

If option 3 would I instal a sub panel or could I split the run, and rewrite the construction heater outlet, and wire the new 20A with the neutral and the black?
 

rlitman

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Messages
24,793
Location
Long Island
...Current construction Heater outlet is a 10 g wire, black, red, white, and copper ground. Only the red and black are connected. Whites are capped off.

If option 3 would I instal a sub panel or could I split the run, and rewrite the construction heater outlet, and wire the new 20A with the neutral and the black?

With four wires, you could install a small sub-panel and break that up to supply the 30A receptacle, plus a 20A circuit. But you may not have the power to run the heater and power washer at the same time without tripping the 30A breaker.

The length of the run will determine the cost to upgrade that to a 6G wire to feed a sub that can easily run both and more at the same time.
 
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Bean438

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May 1, 2018
Messages
22
Option 3 is out. There’s not enough wire to do a sub panel. Just realized that. Unless I could replace the outlet with a box, and use Marietta’s to connect extension wire.


Side question..... I’d like to add lighting. Ceiling is finished so technically I’d have to use conduit or armored cable but why not run the 14/2 on top of the drywall? What’s the difference if the 14/2 is on top of the drywall, or if it was run inside a stud in an unfinished ceiling ?
Either way the wire is not “protected”
 

wyliesdiesels

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Joined
Aug 14, 2012
Messages
20,274
Location
Modesto, CA
Hello.

My attached garage has 15A plugs, and one 30A for a construction heater.

Garage is used to park cars, snowblower, etc. no welding, woodworking. Mainly car washing, and the odd brake job or minor maintenance stuff. (Brakes never need replacing in July, always January -40 thus the construction heater. )

I have a new power washer that requires a 20A circuit, so what would you do?

1. Replace existing 10g wire with a 6g and instal subpanel
2. Just run a new 20A circuit on some 12g
3. Instal 30A sub panel with existing 10g

Option 1 makes most sense, but overkill for what I need, although cost would be offset by shorter 20A circuit run.

Option 2 is really what I need.

Not sure if option 3 is code or not. I’d just have to connect the neutral. Construction heater and power washer would never be used at the same time.

It’s looking like option 1 or 2. Option 3 was simply because the wire is there

Is the 20a power washer 120v or 240v?

How difficult is pulling a new line? Do you plan to make it more difficult in the future?
Do you think you will ever need more power for something else?

Option 3 is only ok if you have 4 wires behind that plug. If you don't have a neutral AND separate ground, forget that option.

240v only subpanels are not forbidden by code...

If the power washer was 240v, then he could go the 30a subpanel/ option 3 route

Not difficult to pull a new line. Remove existing 10 gauge, wouldn’t even have to drill. Let’s say half hour tops. In future it will be no more difficult.

I dont think I’ll need more power BUT I said the same thing 15 years ago when the electrician installed the construction heater outlet. Had I installed a sub panel back then we’d not be having this discussion.

I do want to add additional lighting. I only have 2 led bulbs. Lights don’t,draw much so I think the existing circuit will be fine.

Current construction Heater outlet is a 10 g wire, black, red, white, and copper ground. Only the red and black are connected. Whites are capped off.

If option 3, would I install a sub panel or could I split the run, and rewrite the construction heater outlet, and wire the new 20A with the neutral and the black?

No that woudlnt work because you would have to change the breaker to 20a.

Option 3 is out. There’s not enough wire to do a sub panel. Just realized that. Unless I could replace the outlet with a box, and use Marietta’s to connect extension wire.


Side question..... I’d like to add lighting. Ceiling is finished so technically I’d have to use conduit or armored cable but why not run the 14/2 on top of the drywall? What’s the difference if the 14/2 is on top of the drywall, or if it was run inside a stud in an unfinished ceiling ?
Either way the wire is not “protected”

Yes you could splice in a junction box. No need for mariettas. just use wire nuts sized for #10.
 
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rlitman

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Oct 18, 2010
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24,793
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Long Island
Is the 20a power washer 120v or 240v?

240v only subpanels are not forbidden by code...

If the power washer was 240v, then he could go the 30a subpanel/ option 3 route...

Good catch. I was just assuming 120V, but that's not necessarily true.
But in any case, he has 4 wires, and believes they're too short to use in a subpanel, so it's a moot point now.
 
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Bean438

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May 1, 2018
Messages
22
Power washer is 120v.

My basement is open where the 10g wire is. Yes it’s too short, but could I not instal a box, and then splice another length of 10g and shoot it into the garage? Then I’d have enough length to do a 30a subpanel.

Marietta’s is a typo. I meant marrettes, or wire nuts, lol.

Or what about replace stove plug with box>Splice more 10g>into 30A subpanel

Just discovered that in the house panel, my 30A circuit neutral was cut off. It won’t reach the bus bar. I,can wire nut a wire and connect the neutral right?

I guess the electrician cut it short because it wasn’t being used?

Just want the solution that makes the most sense, and least work if possible
 

Innovate1

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Jul 28, 2014
Messages
4,335
Location
Illinois near St. Louis, Missouri
You could splice in a box in the basement as long as the box will be accessible (not behind a drywall ceiling for example).

As for protection - I think most inspectors would consider a wire run on the side of a stud or joist protected. One the side of the stud/joist facing the space might be considered not protected. Yes, you can see both of them and damage then both if you hit the wall with something but the chance of hitting the one on the side is much less. If you run the wire across the ceiling they might allow that if a board is placed beside the wire. I think this is a gray area and likely to vary by location and inspector.

You don't have to go to 6AWG. You could put in a smaller subpanel with 8 AWG. How far is it to the main panel? How likely are you to need a bit more current in the future? Lots of choices...
 
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Bean438

Member
Joined
May 1, 2018
Messages
22
The box would always be accessible.

I think if I’m gonna run a new wire I’d just run a 6g wether I need it or not. I’d be good for 60A.

As for running wire on top of drywall, I’m adding two light socket thingies, taping into,the existing light socket thingies. Just trying to keep it simple
 

6PTsocket

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Joined
Mar 12, 2014
Messages
4,593
Hello.



My attached garage has 15A plugs, and one 30A for a construction heater.



Garage is used to park cars, snowblower, etc. no welding, woodworking. Mainly car washing, and the odd brake job or minor maintenance stuff. (Brakes never need replacing in July, always January -40 thus the construction heater. )



I have a new power washer that requires a 20A circuit, so what would you do?



1. Replace existing 10g wire with a 6g and instal subpanel

2. Just run a new 20A circuit on some 12g

3. Instal 30A sub panel with existing 10g



Option 1 makes most sense, but overkill for what I need, although cost would be offset by shorter 20A circuit run.



Option 2 is really what I need.



Not sure if option 3 is code or not. I’d just have to connect the neutral. Construction heater and power washer would never be used at the same time.



It’s looking like option 1 or 2. Option 3 was simply because the wire is there
What is the breaker size. It is common and legal to find 15A receptacles on a 20Amp breaker. The intended device most likely has a 15 amp plug. I can only think of one instance when I actually saw 20 amp plugs in use. A device that draws near 15 amps needs a 20 amp breaker and 12 ga. for a cushion against breaker trips and overheated wiring. If the breaker is 20 the wire should be 12.

Sent from my SM-G900V using Tapatalk
 

ford33

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Joined
Feb 26, 2011
Messages
2,118
Location
Chicago, IL. USA
Four years ago I went with option 2 but installed a 30 amp 10 gauge line in the garage for a 240v heater. Used 1/2 emt. I thought I would not need another 240v line.

Fast forward four years, today I am removing all that and installing a 60 amp sub-panel with new 3/4" conduit run and circuits for lights, 20a outlets and two 30 amp 240v circuits.

I should have gone option 1 route from the beginning and saved some time and money.
 
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