Help with shop wiring and lighting...

[Daubs]

New to me acreage with 30'x40' shop (Lester building), no power currently...getting ready to run 100 amp service when ground thaws.

Shop will be used to for woodworking and automotive work. Biggest power draws currently will be Campbell Hausfeld Pro-180 mig welder, 240v 60 gallon air compressor, old-school table saw. May add plasma cutter and heater down road.

At previous house I had electrician run 240v line to garage. I pulled that breaker box from old house and plan to use in the shop.

I've been reading and reading, searching this forum, and reading more. Please feel free to point me in direction to answer these questions:

Air Compressor: Box already set up with 20A/240v circuit breaker. Compressor will be ~30 feet from the box, by my calculations I should be able to use copper 12AWG, correct? (12/2 with red tape around the white wire...)

Welder: Box already set up with 20A/240v circuit breaker. Want to put 240v outlets on east and west side of the shop. East side will be 15' from box, then will run line up wall, across truss, then back down wall to west side of shop, another 40' of wire (~55' total). Calculator calling for copper 10AWG(?). Can I run 10/3 to junction box, branch off to first outlet with pigtail, then run remainder over shop to west side? Note: Will only be using one outlet at a time.

East Outlets: Had some materials left over from previous project, ran copper 14AWG up over the 16' door, down to SE corner of shop, daisy-chained 6 duplex 15A outlets. Total length of line is around 60'. These will be used primarily for battery tenders on John Deere, ATV's, vehicle, hand tools. Will use 15A breaker due to 14AWG wire. Overall length too long?

West Outlets & Workbench: Plan to use 12AWG and daisy-chain 15A contractor/duplex outlets, with 20A breaker. Will probably do eight outlets per breaker. Use will be table saw, miter saw, hand tools, computer, stereo, wifi router, etc. Can't see a need for 20A outlets...and someone pointed out in another post that 15A contractor outlets have 20A inners(?).

Overhead lighting: Platonic Solid recommended GreenTek GT-H2-110W, 3x3 pattern for 9 total lights. With budget, I will likely trim to 6 total, 2x3 pattern. At 110W each, total draw 660W. I was hoping to use 14AWG on one 15A breaker. Will this be heavy enough wire to daisy-chain all the lights on one switch? Or do I need to jump to 12AWG?

Other suggestions? Thanks! Daubs

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[pattenp]

Make sure the circuit is the proper size for the compressor that you have. Circuit size is determined by motor HP and may require to be hardwired vs. outlet and plug. If the compressor came with a cord and plug then size the circuit based on the manufacturers suggestion.

Welder only requires **/2 wire, not **/3. Neutral should not be needed. Also #12 is fine for that welder.

 

[sberry]

You could trade wires here, 12 for welder and 10 for comp. But,,,, if you are going to daisy chain welder recepts use the 10 and needs to limit it to a 30A breaker. You could do yourself a favor in this whole scheme and I pretty much do this religiously,,, I run all the lights, bathroom fans, smokes on 14 and put all the recepts separate from all that stuff on 12/20 circuits.
I do not see a ground wire with the current carrying conductors to this panel and since it appears this is a detached building requires a main breaker. The electric doesn't really know but wires smaller than 6 are not sposed to me remarked. Needs a green or bare ground to the welder outlet.
I see that the ground strap isn't connected to the neutral bar,,,, this was allowed way back in the day with 3 wire feeds and would be better than not in this case as this panel and all the equipment grounds are "floating" so to speak here and not grounded. This leaves the box and any equipment with the potential to be energized at 120V without tripping a breaker in the event of a fault. Very very dangerous.

I am going to say,,, all for the purpose of this discussion but all 120/240 panel to panel feeds MUST be 4 wire.

 

[Daubs]

Make sure the circuit is the proper size for the compressor that you have. Circuit size is determined by motor HP and may require to be hardwired vs. outlet and plug. If the compressor came with a cord and plug then size the circuit based on the manufacturers suggestion.

Welder only requires **/2 wire, not **/3. Neutral should not be needed. Also #12 is fine for that welder.

Compressor has plug and outlet...you can see the outlet in lower left hand corner of first picture.

Welder has this plug...

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I did three wire set up.

 

[Daubs]

You could trade wires here, 12 for welder and 10 for comp. But,,,, if you are going to daisy chain welder recepts use the 10 and needs to limit it to a 30A breaker. You could do yourself a favor in this whole scheme and I pretty much do this religiously,,, I run all the lights, bathroom fans, smokes on 14 and put all the recepts separate from all that stuff on 12/20 circuits.
I do not see a ground wire with the current carrying conductors to this panel and since it appears this is a detached building requires a main breaker. The electric doesn't really know but wires smaller than 6 are not sposed to me remarked. Needs a green or bare ground to the welder outlet.
I see that the ground strap isn't connected to the neutral bar,,,, this was allowed way back in the day with 3 wire feeds and would be better than not in this case as this panel and all the equipment grounds are "floating" so to speak here and not grounded. This leaves the box and any equipment with the potential to be energized at 120V without tripping a breaker in the event of a fault. Very very dangerous.

I am going to say,,, all for the purpose of this discussion but all 120/240 panel to panel feeds MUST be 4 wire.

Thanks. I like idea of running all lights on 14, and all other stuff on 12/20.

Remember, first picture is the box set up in my garage at old house. Electrician installed. I pulled and will be putting it in the shop -- good advice on doing 4 wire set up out there.

I plan to bury the wire from house to shop myself, and get electrician to do all the hookups to house and this box.

Safety is my #1 concern here...hence, so many questions : )

 

[sberry]

The things I quoted are good advice they need to be done that way to pass an inspection and provide proper operation and safety. I got to include most of the words because those are really 2 different things.
I would say the installer of that panel may have worked in factory maintenance, someone that saw a couple installs and heard some code, He knew he needed another bar and had seen older work with 3 wires as is the service entrance. And a lot of panels.

This would have implied in the existing installation and in a new one. I don't think the installer was trying to rob someone here he just doesn't know. Most electricians doing service work have seen it. I did **** wrong a lot and my mechanical design looks so good I made a lot of mistakes when I learned this the hard way. I even went back around some installs I did when a kid I fix.
I found a handyman job a while back. He did some good stuff but he copied an existing install. A thing he really did good in along the way was use the right wire, he buried it deep and it was UF 10/3 WG. It was a lot of work. But he married the N&G on the neutral bar and left the bond screw out. There were only a couple circuits.
I added moved breaker and put them side by side so there was one for a local freezer and light, another for the rest of the place.
The installer did a fair job of putting the wire out of the way cept for one spot. He stapled decent and I opened a couple plastic boxes and he had twisted the grounds together pretty good/ continually and to the devices. He had hooked on to a shed from the back of this general,,, same thing put in 12/////3 uf had it on 20A. I added a common switch just inside it and gfci this whole scheme at the first outlet. Added a ground rod and equipment ground bar, opened the source panel, sub it was from. Earlier I grounded that panel and correct the same issue due to the fact it was installed by a heating bud who was a good craftsman but didn't wire it right.
So anyway,,, I should go to a job this after noon and do it.

 

[Daubs]

sberry, I was reading the sticky on this thread...reason box in previous house was only three wire (picture #1 in thread)...it was installed in 2005. Prior to the change in 2008.

 

[sberry]

I ran in to a guy I knew when we was kids and didn't know squat. I quizzed him just a second 45 years later. His job is white collar but is smart and can read and he knows exactly, he learned this principle like a professional. The installer did use a good wire on that panel and got the fundamentals of the over current requirement and wire size for that welder.
That is a 50A welder plug and all legit welders in its class come with it. The thing might work fairly well. If the method it is installed with it allows 12 wire and circuit breaker to 50A. I know a master got his buzzer on a 12/50,,, says,,, it allows 85 ft and I am 25 and even if I put a cord on it 50 for the occasional rod I burn on a 105 setting.
All the duty cycle and distance is rated for max and old voltage and the draw is around 40, maybe 5 volts loss for a couple minutes a month at 1/2 the allowable distance.

How ever, physical connections, heat at breakers and recept is soooo much better and the V drop when working becomes negilgable even at consider able distance with number 10 wire,,, only a sliver of improvement by going to number 8 and from 8 to 6 to hard to measure... ha You can buy a few ft of 10 for this circuit. In a Buds shop I wouldn't be scared to run a couple 10/30 hooked together for convenience. If a heavier welder ever gets plugged in it will trip the breaker, if 2 were used it would. Wouldn't be a fundamental error to safety. On their own a 10 can run on a 50 for most 50A req machines. For the biggest machines they allow for this circuit are number 8 wire, hence the ready made cord comes 8.
For that little machine could use a 12/25 ft from your 10/30 outlet and not notice any droop.

 

[sberry]

sberry, I was reading the sticky on this thread...reason box in previous house was only three wire (picture #1 in thread)...it was installed in 2005. Prior to the change in 2008.

Yes but the bond from N to G is missing, it must be installed with 3 wires. With 3 wire don't even need the second ground bar,,, it needs a bond to box from the neutral bar same as a main.
Neutral are operating currents, the other end of the wire is at grounded neutral which makes its potential to ground low unless it were to become disconnected. The goal of the 4 wire system is,,,,,,,,,,,,,,,, to run neutral on insulated wire back to service main vs letting it stray thru bonding and returning on ground wires or other interconnected metal parts.
I got a Bud who knows more about this that to fail to realize all the steel in the place is carrying electrical current due to the fact he got a panel install wired wrong,,, duh Also heard that thing about breakers at 20A and some other basic ********.
So with 3 wire even faults may have alternate pathways as well as a lot of pipes, ducts, even phone and other wire may be current carrying. With 4 the neutrals are insulated forcing all the operating current to a single wire goes along with the source wire and adding a separate wire which ties in to a web of sorts but continuous back to service main provides a pathway for faults. It keeps all conductive materials that are hooked to the electric system all bonded along with any other metal which could have the potential to become energized are at the same potential and have a direct wire connection to deliver a high current fault. Directly with the current carrying conductors in same pipe, cable or raceway, etc.
This is what makes gfci so good. I did have a cord short to neutral a while back and it tripped the breaker and not grfci although but could been close as it was on a metal bench,,, but,,,, say and ungrounded appliance falls in to an ungrounded metal sink the gfci is failsafe its so sensitive.

 

[sberry]

A lot of ground and bond of equipment, duct and pipe in a home need a 10 wire. bBut the idea is that any circuit in this case 10 would provide short circuit for any circuit likely to become energized from it. Number 10 wire circuits like dryer are 10 ground, same for electric range use a 10 so a 10 bond to the gas may be sufficient. Other ground wires, rod wires may be different for slightly different reasons.
Maybe a bond needs to be larger for short circuit to 200A,,, say from a 200 feed thru or even breakers of conductors larger than 6/60 may require 8 or 6 with conductors/breakers above 100.
In my own case I have a steel building, service entrance panels are bolted to building frame and along with the N/G bond screw installed a big ole chunk of number 2 copper bolted to a lug welded to the building frame. I think might be legal but it was free scrap wire it got 2.

 

[Sevenhills1952]

I didn't see mentioned here but if I had to do over again I would have run my electric house to garage through conduit, PVC pipe, etc. Same with water.
Knock on wood all's well...but that sure would be nice if I ever had a problem, so easy pulling wire or pipe through another pipe.
I did run extra cables in ditch with a utility box at both ends, about 6ft. coiled up inside. Over the years handy for wired phone, alarm, etc.

Sent from my SM-S320VL using Tapatalk

 

[sberry]

You been using that machine on a 20 breaker? The 20 is rated output, some of these go above that and run about 22 or 23A wider open with 030 solid. They really need a 30 breaker. But if you are using a single outlet 12/30 is fine too. The machine has a 12 cord. Like your other general use circuits multiple outlets on any circuit shouldn't be able to overload the wire.
A circuit may allow 12/50 to one outlet but if 2 is used it needs 8 or 6 for 50A and there is a possibility 2 number 12 could be spliced to an 8 from the breaker.

 

[rburke65]

Do not use direct bury wire. PVC conduit is inexpensive. Use 2”, sweep 90s, bury an extra conduit...or 2. This is wisdom talking to the inexperienced......

 

[rburke65]

And, that panel in the first post....is that the one you want to use? I’m thinking that’s going to get filled quickly!