240V Wiring Questions - Wire Gauge

[countrybumpkin]

Hi all. Trying to do some long term planning before I put in some garage heaters here in NW Ohio.

Space is a 24x24x8 with hip roof. Partial lofts.

Currently completely uninsulated.

I have already 1 240V/20A circut with plug for my lift or whatever else I need to run for now. Wired with 12-2. The 240



I am looking to add:

-Heaters (2x 5kw)
-Insulation
-Larger Welder/Plasma



Current situation:

Garage Wiring (CURRENT)
240V @ 20A
12-2 Wire
Garage 240 (CURRENT)
240V @20A
12-2 Wire



Usage:

Lift
240v
15A peak draw
Heaters
2x @ 5kW
21.6Amp Draw
Constant - Full time winter
Welder
240V @ 40A


Heaters will most likely run in conjunction with welder or lift for 4/mos of the year.



Based on this I am thinking I will need to set up my 240v on 60A breakers with either 6-3 or 8-3 wire correct?

 

[pattenp]

Are you asking about sizing a main power source such as a subpanel for all the 240V circuits?

 

[wyliesdiesels]

Is this shop or garage attached or detached?

 

[countrybumpkin]

pattenp - Yes.

wyliesdiesels - Detached.


The garage sub panel is routed with ~15ft or wiring from the main panel in the house.

Both the house and the sub are using 20A 12g.



I will have to upgrade both.

 

[wyliesdiesels]

you will need to run a new feeder to the garage then.

 

[dcg9381]

6/3 copper @ 60A would get it done.
Might look at 2/2/2/4 AL wire, probably costs less/same - capable of 90A.
Main difference is pain-in-the-*** to pull, so it depends on your conduit size.

6/3 can be pulled thru as small as 3/4" (1" recommended).
2/2/2/4, 1 1/4" or larger.

 

[wyliesdiesels]

6/3 copper @ 60A would get it done.
Might look at 2/2/2/4 AL wire, probably costs less/same - capable of 90A.
Main difference is pain-in-the-*** to pull, so it depends on your conduit size.

6/3 can be pulled thru as small as 3/4" (1" recommended).
2/2/2/4, 1 1/4" or larger.

6/3 as in UF-b? good luck pulling that through 3/4"...

 

[Speedy Petey]

6/3 as in UF-b? good luck pulling that through 3/4"...

LOL, right? I wonder if he's ever seen 6/3UF.

 

[Speedy Petey]

6/3 copper @ 60A would get it done.

You do realize he said he'll have a larger welder/plasma? That alone will likely require a 50 or 60A circuit.

 

[pattenp]

6/3 as in UF-b? good luck pulling that through 3/4"...

I believe it will take 1" or even 1.25" conduit to meet the fill requirement for a single cable of 6/3 UF-b.
Edit: After looking a the wide dimension of 6/3 UF it may take 1.5" conduit.

 

[wyliesdiesels]

I believe it will take 1" or even 1.25" conduit to meet the fill requirement for a single cable of 6/3 UF-b.

Im not gonna even bother calcing that.

It would be foolish to pull such cable through conduit when there are easier materials to do so.

 

[strutaeng]

I would just pull a larger wire. 6 gauge seems light for running the heaters and welder or plasma. What most here recommend is Al wiring with a subpanel.

Also, you didn't include an air compressor. Plasma cutters need something like 5-6 CFM, so throw a another decent load to the mix.


#2 Al in conduit will get you plenty of juice.

 

[dogdog]

why would op needed to put UF-b inside a conduit, if he already have conduit, regular THHN or THWN would fit fine... I think I fit 4 or was it 3 #6 THHN inside a 1" emt not an issue at all