Wire it myself?

[Owen]

Hey everyone,
I have a TIG welder that specifies a 50A circuit, it's currently on a 30A. I rarely need to turn up the juice on the TIG but I did today and kept tripping the breaker. I had to keep running out of the garage and in to the backyard where the breaker is, as you can guess, it's a pain and my welds look like **** now!

I called an electrician and was told $450 to do the new circuit, cheaper if I do it myself and have him hook it up. I'm strapped for cash...

My questions are,
1. Can I do it ALL myself or should I do as he told me?
2. Where can I find info on the type of wire, conduit, etc. specified in the codes?
Thanks!
Owen

 

[Owen]

Here's some pix of the breaker box.

I've done cars and computers but never a house...I'm guessing the wires coming out of the actual breaker are going to the outlet in the garage. Where is the input power coming from?

Also, the box is installed flush with the wall, this is gonna be a pain...I'm thinking of adding a subpanel to the wall next to it, having the power input from the old box feed into the subpanel. Any problems with this?

 

[dink]

$400 for **** crack show and labor...$50 parts

Do it yourself....shouldnt be that hard

 

[Owen]

$400 for **** crack show

HAHAH! That must be the job requirement when they first hire you!

I'm just worried about burning down the house (and being found responsible for it by the insurance company)

Owen

 

[bmwpower]

100A panel?

 

[mikeyr]

It should be easy, just trace the wiring that is there and increase the guage, I think Lincoln calls for 6gauge for their TIG, it might be 8 though. I remember doing mine in 6, easy since you are just "upgrading" what is there.

 

[kartracer55]

In your case Id say run all the wire your self, and have the electricians make the connections. Pulling cable is a PITA, which Is why he quoted you 400.

Jim

 

[bmwpower]

HAHAH! That must be the job requirement when they first hire you!

I'm just worried about burning down the house (and being found responsible for it by the insurance company)

Owen

Depends on the area you live in. I'm able to do the wiring myself and have the inspector inspect it. If it passes, I'm okay as far as insurance goes.

 

[kartracer55]

Electrical Isnt that hard to do compared to other things, such as plumbing. You just need to know the principals. I understand it, but I dont go near it.

Jim

 

[TOMWELDS]

No offense, but you might want to go with the electrician when you get the cash. One option, I like to match my wire sizes to the breaker (IE: 30 amp -#10 and 50 amp- #8), In the code, i think they allow a 50amp breaker with #10 for welders only. Check this with your local inspector first. If its ok, you only have a breaker change.

 

[Owen]

Thanks,
I guess I'll have to check the code but the electrician I talked to mentioned #6 for power and #8 for ground.

Tracing the existing wire and removing it sounds like a hellish job for my house...I was planning on adding a whole new circuit but terminating it at the existing outlet (getting rid of the old wires).
Owen

 

[TOMWELDS]

50amps only needs #8 and a #10 ground. You can go larger, there's nothing wrong with that.

 

[Owen]

I'm gonna go to Home Depot tomorrow and price everything out. If it's just a little cheaper, I'll have the electrician crawl through the attic instead of me.

Prices are hourly right? There was a space in the attic that was almost too small for me to get through...and I'm 5'5".

So, shopping list is...
50A breaker
subpanel box
30-40ft of PVC conduit (3/4"?)
15 feet of metal conduit (for the outside portion)
50 ft of #6 wire (x2)
50 ft of #8 wire (does the ground have to go from box to outlet, or can it be grounded elsewhere like in a car?)
various bends, elbows, and through-wall hole things
conduit hold-downs

Did I miss anything?

 

[Owen]

50amps only needs #8 and a #10 ground. You can go larger, there's nothing wrong with that.

You sure about that? I'm gonna follow your advice then!
Owen

 

[Owen]

The difference in opinion on wire size and amps got me thinking...what about upgrading to a 40A breaker with the existing #10 wiring? It may be just the little extra juice I need!

 

[bmwpower]

#10 is only good for 30A. You'll need a larger wires for 40A.

 

[TOMWELDS]

Yep. #8 on 40 and 50 amp...#10 ground on both.

 

[Owen]

Ahh well...guess I'll go tomorrow and add everything up. Should I buy wire separately or get the cable 8-3?
Thanks again.
Owen

 

[TOMWELDS]

Cables much easier. You would need 8/2.

 

[Owen]

Ahh, couldn't remember if it was a slash or a dash! So I would just buy the ground cable separately and pull it all through. Sounds easy enough!
Owen

 

[bmwpower]

Ahh, couldn't remember if it was a slash or a dash! So I would just buy the ground cable separately and pull it all through. Sounds easy enough!
Owen

Is this going to be partially run in conduit?? You can't run individual cables without running them through conduit all the way. You'd have to use romex.

No. 8/2 romex = 2 hots AND a ground. Is that what you're asking?

 

[Owen]

I was planinng to run the entire length through conduit. Doesn't it have to be?

 

[Wile1Coyote]

I don't think so as long as it is run inside the walls. Needs to be a certain height above the floor as well I think but no as long as it is enclosed conduit is not required.

 

[bmwpower]

I was planinng to run the entire length through conduit. Doesn't it have to be?

If you run individual wires, then, yes, they have to be in conduit. If you use romex (wires in a jacket) then you don't have to as long as they are not exposed...actually I would not recommend it either. Pulling romex of that gauge through conduit can be tough to do. The stuff just doesn't bend like a thin wire does.

Maybe we could get a better picture if you let us know where you're planning on running the wire/conduit. I'm still fuzzy as to what you're trying to accomplish.

 

[Owen]

OK, looks like I'll only need conduit in small runs. Outside at the boxes-to-attic and then from attic-to-outlet in the garage.
Here's some pix.
The main box is sunken into the wall, getting a cable out and into the subbox is gonna be a pain. I'm planning on using 90 conduit here.

For the exposed vertical portion, they had sunlight resistant, above/underground scdl 40 PVC. Or should it be metallic?

I'm confused about where to draw power for the subbox. Add a new breaker here which feeds into the sub? never mind the arrows on this one, this is just a draft.

Now for this so-many feet above the floor, does that apply to attics as well? I was just gonna loop it out of the way of anything so it's not a jungle in there.
Thanks,
Owen

 

[bmwpower]

Ok. I think I know what you're trying to accomplish now.

So you plan on installing a subpanel, fed from the outside panel.

Does the subpanel have to be outside? Is there anyway to run the power inside the wall or inside the house to feed the sub?

You shouldn't need metal conduit for this run, gray PVC will do.

To get power to the sub, you'll need to add a double pole breaker in the main panel and run the 2 hots from it. It's generally a good idea to add a high power breaker further up in the main panel since heat rises.

How many amps is the main panel? How many amps is the sub?

As for the type of wire, I would use individual wires to feed the sub panel. You should be able to use romex to feed the garage. This way you won't need conduit in the attic. Romex does not have to be a certain height in the attic, just as long as it's not in harms way, ie. across a walking area. It has to be secured though, usually using staples not to exceed 4-1/2' intervals.

 

[Owen]

The subpanel doesn't have to be outside, but I thought it would be safer to have it where it is, if something happened the hot wire would end at the box outside rather than go through the attic. Plus, I can't get into the walls and there isn't room inside the house.

I'm not sure how many amps the main panel is...the sub will be a 2-space 125 amp. I'll cut the Romex up to use the individual wires, I can only buy a 125ft spool for the 50ft or so that I need.

Maybe I could cut a notch in the cover of the main panel and secure a 90-degree conduit there to feed the sub. Like lifting the hood of a car with a big carb hat sticking out of it.
Thanks,
Owen

 

[bmwpower]

The subpanel doesn't have to be outside, but I thought it would be safer to have it where it is, if something happened the hot wire would end at the box outside rather than go through the attic. Plus, I can't get into the walls and there isn't room inside the house.

I would think you'd have less problems without the subpanel. Adding a subpanel adds another chance for water to get into the system, especially if it's outside. Have you considered adding breakers to the main box to feed the garage outlets instead of installing a subpanel?

This assumes you have enough spaces for the added 125amps in the main panel. Keep in mind, you don't want to add 125amps to the entire service if it can't handle it. That's why I asked how big the main panel was. You should be able to tell by the main breaker at the top of the panel.

I'm not sure how many amps the main panel is...the sub will be a 2-space 125 amp. I'll cut the Romex up to use the individual wires, I can only buy a 125ft spool for the 50ft or so that I need.

If you forego a subpanel, you can just run the romex from the main panel, through the conduit, into the attic and into the garage.

Maybe I could cut a notch in the cover of the main panel and secure a 90-degree conduit there to feed the sub. Like lifting the hood of a car with a big carb hat sticking out of it.
Thanks,
Owen

I don't think you're allowed to cut a hole in the cover. You'll have to come in from the side or the rear. The side will be difficult. It may be easier to get in through the top. You may have to custom bend a right angle to make it work. Then use an LB on the exterior, then a straight piece up the wall. Either way you're going to have to break up some of the stucco.

 

[Owen]

"Have you considered adding breakers to the main box to feed the garage outlets instead of installing a subpanel?"

Uhhh..no...DOH! not until you mentioned it. I was so set on not being able to replace the 30A with a 50A. I didn't know I could add a new breaker towards the top and draw a new circuit. That's what you're suggesting right?

Getting into the walls is still not an option. So I will still have to use the 90 bends and maybe break a little stucco. Well, I will check in the attic again to see if I can get to the top of the box, it's pretty cramped in there tho.

Anyway, the entire panel is 100A with 145A already being used for circuits that I am aware of. I will replace a 30A with a 50A so that bumps up total usage to 165A. As long as everything's not running at the same time it's ok I assume. I will just have to make sure when I'm welding.

What's the LB you mentioned in your last sentence?

So to recap, add a breaker where the yellow box is on my third picture and bring the power from it directly to the outlet?

Thanks again,
Owen

 

[bmwpower]

"Have you considered adding breakers to the main box to feed the garage outlets instead of installing a subpanel?"

Uhhh..no...DOH! not until you mentioned it. I was so set on not being able to replace the 30A with a 50A. I didn't know I could add a new breaker towards the top and draw a new circuit. That's what you're suggesting right?

Getting into the walls is still not an option. So I will still have to use the 90 bends and maybe break a little stucco. Well, I will check in the attic again to see if I can get to the top of the box, it's pretty cramped in there tho.

Anyway, the entire panel is 100A with 145A already being used for circuits that I am aware of. I will replace a 30A with a 50A so that bumps up total usage to 165A. As long as everything's not running at the same time it's ok I assume. I will just have to make sure when I'm welding.

What's the LB you mentioned in your last sentence?

So to recap, add a breaker where the yellow box is on my third picture and bring the power from it directly to the outlet?

Thanks again,
Owen

Yes, if it's only one (double pole) breaker, then yes, just add it to the main panel and run the wire.

I was afraid you were going to saw 100A. It sound like you might be reaching maximum capacity for power, but I am only guessing. Adding a 50A breaker which will draw a LOT of power may cause problems on such a small (100A) main panel. It may be able to be done. The only way you will know for sure is to do a demand load calculation and see if you have enough reserve. Do you have any big power loads in the house, ie, A/C, oven, heat, etc?

An LB (see attached) will allow you to make a 90* bend. They come in metal and PVC. It has a cover you remove to aid in pulling the wire. You've probably seen them before. You will either have to use an LB or get a right angle "sweep" which requires a larger offset to make the turn, which it doesn't look like you can do in this case.

You will need a 90* bend coming out of the box to the first LB though - It will need to be threaded on the box side so that you can screw on the retaining ring to keep it attached to the box. This might need to be a custom bent piece to make the radius of the turn. Attach the LB to this bent piece. Then attach a piece of conduit going up the wall. Finally another LB at the top going into the wall. Then conduit into the wall.

The hardest part will be the first piece of conduit.

 

[Owen]

Cool, thanks. I was playing with that piece at Home Depot, and was making calculations on what sort of male/female parts I need to do the conduit.

Yes, I do have a large current draw, an oven and the heater, but that's it. I will just have to make sure they're not in use when I'm welding.

Owen

 

[bmwpower]

Just be careful. Pull too much current and your main panel breaker will trip.

Do you need to get the project inspected?

 

[Owen]

If the new breaker is 50A and the main is 100A with nothing else being used, the 50A will trip first...is my understanding???

I'm exhausted, I did the wiring today. Took me 45 minutes to do one of the LBs, the other ones were easy. Thank god I didn't use 6-3 cable tho!

Now all that has to be done is foam up some gaps, wire the breaker and wire the outlet.

I am still considering having an electrician do the breaker side. I don't know if I need to get it inspected...???
Owen

 

[Owen]

Damn I spent a **** load of money this week!
$400 for a drill press
$200 for the wiring and stuff
$200 for a transmission for my project car
$80 or so on a bathroom ceiling fan and resin for fiberglassing.
$80 on an oscilloscope off ebay (it was $45 for shipping!)
$40 for scope probes...
Damn!

 

[Owen]

I was so upset by the money that I forgot to ask...

Red and white are power, black is ground, and the copper cable is...?
Thanks,
Owen

 

[Jay H 237]

I was so upset by the money that I forgot to ask...

Red and white are power, black is ground, and the copper cable is...?
Thanks,
Owen

No, the red and black are hot (power), white is neutral, and the copper (or green) is ground.

 

[bmwpower]

If the new breaker is 50A and the main is 100A with nothing else being used, the 50A will trip first...is my understanding???

I'm exhausted, I did the wiring today. Took me 45 minutes to do one of the LBs, the other ones were easy. Thank god I didn't use 6-3 cable tho!

Now all that has to be done is foam up some gaps, wire the breaker and wire the outlet.

I am still considering having an electrician do the breaker side. I don't know if I need to get it inspected...???
Owen

It may be too late now. Usually they want to see the conduit in place before you pull the wire through it. What size conduit did you use?

The breaker side is easy, but you need to be carefully. The main lugs are always hot. Do not come close to them. Turn the main breaker off (all power in the house will turn off). Insert the new 50A breaker into the panel space. Attach the ground to the ground bar. Wire up the new breaker (black/red).

You are correct. However, if you have your oven on and you heater then that will not occur. Let's say the oven is 40A and the heater is 40A as well (80A total) and they're both on. Then you decide to weld with the 50A welder. Click! The 50A breaker will NOT trip, but the main will trip.

This assumes that you don't know the heater and oven are on, which may not be the case in your situation, ie. you're not married.

 

[Owen]

Thanks Jay H 237 and bmwpower,

I used 3/4" PVC conduit and 2 smooth 90 degree bends to get into the box. No conduit in the attic.

Owen

 

[Owen]

Looking at the main box again, there appears to be no neutral bus block, the ground box has both solid and stranded copper going to it...
Owen

 

[Jay H 237]

Looking at the main box again, there appears to be no neutral bus block, the ground box has both solid and stranded copper going to it...
Owen

The neutrals and the grounds are tied together at the box, in otherwards they share a common bus. The ground is just a second path for the electricity to follow in case there ever was a problem.

In the photos you posted in post #2 you can see where the neutrals (white wires) and grounds (copper wires) are terminated together in the lower left hand corner of the box.


Jason