Electrical Advice - 220 Line?

Growroom Design
#1

Hello growers -

So my setup, when running at its max, will approach 2500 watts. It is currently spread across two breakers (via extension to an adjoining room), but that is still a lot more than I would like to be running through this place’s aging electrical system.

In the interest of taking some pressure off the wiring, I am trying to figure out the best way to utilize an existing 220 line which I can dedicate to our favorite cause. The one I have in mind is in the basement and intended for use with an electric dryer, but we have a gas unit so it is not used.

If my grow space was in the basement also I would just run a short extension cord to a converter, but I don’t really know the implications of using a 40-50ft extension. It would actually be pretty simple and not at all invasive (it’s a rental) as I could just run it straight up a cold air return duct.

Is this a workable approach? Are there dangers or other reasons it is just impractical? Any advice would be appreciated, and thanks!

Vesti

Edit: To be clear, the gals are on the second story, so two stories up from the basement.

1 Like
#2

bigger the better in wire size 10/3 at 50 ft can do 50 amps

a bit more but you should use only 20% of the total

I did a grow on a extension 10 or 15 years ago because my power

in the house was sketchy

but I ran mine on the ground and it was winter and cold

all the best

Dequilo

1 Like
#3

Im not a certified electrician but you could hard wire from existing 220 up to where your working. You would need some heavy gauge insulated wire. Probably some 10/3 at the least. The farther the electricity flows, the bigger the wire to get it there. Once your there you can,thru a breaker box break it on down to smaller wire for shorter runs,12/2,14/2. The shorter lighter loads on the smaller wires. They sell little screw/nail clamps to hold wires in place to keep safely out of trip hazard. Add your box and recepticals mounted securely. Shouldnt be a problem. When you move, unscrew everything and take with you.

3 Likes
#4

‘Cheap and cheerful’… You can get away with a 12 gauge extension but that is pushing it a little.
2500W @ 220VAC is about 12 Amps. That’s going to be 2.5V drop on 12/3, OK for temporary work but I’d go 10/3 if you can. The ‘probably good news’ is that you would have a mostly free circuit in the grow room if you move your load to the 220…

Running wire through a cold air return is not going to be ‘to code’ etc.

Cheers
G

2 Likes
#5

existing 220 line is just two hot legs at 110/120… the carrying capacity depends on the breaker in the box and the existing wire. Yes you could match that wire and run it to your location and do the subpanel thing there.

you should be able to do a lot on 10 gauge conductor…that should be 30 amps unless its really far.

3 Likes
#6

If you have an electrician who is willing to look the other way, he can extend the 220v. You can as well, but mounting a box in concrete is a bitch without the right tools. But be VERY careful to use ONLY things rated 220+. Anything 120v could arc and big fire.

1 Like
#7

Thanks, everyone.

Yea, electrical stuff always gives me pause. I know it’s conceptually pretty simple, but the outsized consequences of small mistakes tends to keep the tinkering impulse at bay.

Unless I run into some unforseen obstacle, in a couple weeks I’ll snake an extension down the cold air return and go from there. A formal/safe install feels beyond my ken (at least beyond my confidence), and I do like the idea of being able to just pack it all up when eventually I move.

#8

if you paid 50 us dollars for a fifty foot cord 10/3 and it kept

you from burning you house to the pavement

I would say a cheap invest

all the best

Dequilo

5 Likes
#9

Sorry to smack on an old thread, just wanted to encourage you to do what you spoke of. I built a 220v box sub-panel which replaced maybe 3-4 110v outlets. Now I have one box which plugs into a single 220v dryer outlet which runs 2 rooms without even getting warm. Used it for a few years now and never looked back. Best thing I ever did for my rooms.

2 Likes
#10

Thanks man.

It’s funny, I never got around to doing anything (semester started and that usually squeegees a few good plans off the old consciousness), but began thinking about it just a few days ago, then your post popped in.

My next door neighbor’s house caught fire on Tuesday, some freak thing with a window air conditioner not in use but still plugged in (water damage played a factor). No one was hurt, but a family of two adults, six kids, and three dogs lost their home.

So yea, I think you are right, and thanks again for the prompt!

1 Like
#11

I second! I love using 220v in my work in the entertainment industry. (Just as long as someone else runs the cable).

Investing in a good electrical run with plenty of copper is investing in your safety.

3 Likes
#12

I hope that you followed none of the advice in these posts.
First off…is the 220v line in question a three wire (2 lines x 1 ground/neutral) or a four wire (2 lines x white insulated neutral x bare copper).
Only the second…four wire will be useful to you for a sub panel.
If it is a three wire, you can change it to a single 120v circuit extended from there…I’m assuming since it was a dryer it was a 30a circuit previously so at least # 10cu. or #8 aluminum…
Also if converting from copper to aluminum…use the correct wire nuts or ilsco connector.
If you did it the other way and violate the NEC and burn the house down…well, they no pay!
Let me know that before I continue.

6 Likes
#13

Those are super good points… Must be 4 wire.

Aluminum to copper… probably just call and electrician IMHO.

1 Like
#14

Master since 1998.:+1:

3 Likes
#15

Thanks Catchin1, I appreciate the advice. I’m talking in a few days to an electrician who will advise off the books. He’s done a little work on the property and has a pretty good sense of what is going on generally here.

And I can probably pay him in weed!

3 Likes
#16

And Chem, yea, (your post landed as I was writing the previous) I’ll be getting some advice. And thanks.

2 Likes
#17

10 gauge copper is only good for a 30 amp breaker.

8 gauge cu is good for 40 amps
6 gauge cu is good for 50 / 55 amps

3 Likes
#18

YUP! :sunglasses: :+1:

Cheers
G

1 Like
#19

Glad you chimed in there @Catchin1. I was wondering the same about the 240 circuit. If it was able to split into 2 - 120s with 2 hots a neutral and ground, and if it was a large enough wire size to accommodate a sub panel. I don’t ever see aluminum inside a residential dwelling, but that doesn’t mean it doesn’t exist. I’d suggest an electrician just to be on the safe side. Things seem to be panning out that way. Good luck !

1 Like
#20

Yeah aluminum branch circuit wiring was common back in the 50’s - 60’s and the ampacity of aluminum is different than copper. With aluminum wiring you need to make sure the terminals you connect it to are rated for aluminum, they would commonly be marked “CU/AL”.

3 Likes