Does this look sane? Wiring

[hell_fish_65]

This is the plan for my shop. I know little about wiring. I got one of the HD books and read through it and decided to draw it up. Anyone see any big (or little) flaws in the lay out?

 

[PAToyota]

Hard to say... Where are the overhead doors?

Looks like you will have a dark area over on the left with no lighting over there. Code is typically that you need receptacles on every wall over 2' long, so you need them on the left-most wall. Also, a six foot cord must reach a receptacle - so typically a receptacle every eight feet. I'd also want at least one light switch at the door on the left. Just initial thoughts...

 

[hell_fish_65]

Added the overhead doors and windows. The dark area is just storage. The shop is 1500 sq. ft if it matters

 

[MXtras]

I don't want to pretend to be able to see everything on your drawing - some lines are extremely faint..... BUT - I can say this; plan now for future expansion. It is more cost effective now than add later. And if you have to decide on wire size, go with a larger wire. I ran 12Ga for all outlets and I used commercial duty outlets - not the cheap **** from HD or Lowes. Contractor grade stuff *****.

Convenience outlets are never numerous enough! It looks like you have thought things through fairly well, except I did not detect any additional 'high' voltage supplies for a future welder.... I would suggest providing for at least one more additional 220V source.

Looks reasonable (from what I can view)!

Scott

 

[PAToyota]

So about a 30x50 building? In that case I'd say you don't have near enough lighting or receptacles and my other comments still apply.

 

[hell_fish_65]

Your probably right about the lights. They are 4 ft double bulb florescences on every other rafter until the loft.

The big question is what breaker box should I go with? It will have to be mounted outside and I want affordable breakers. Suggestions?

 

[MXtras]

The question that begs to be answered is what will your service feed be capable of? Are you feeding this from an existing panel or a separate feed?

Scott

 

[PAToyota]

For reference, my 1500 s.f. shop has a 200amp panel and downstairs (900 s.f.) has eleven 8' double bulb HO fluorescents... That lights things up fairly nicely.

There was another thread about breaker panels. My suggestion was SquareD QO panels and breakers - a bit more expensive, but worth it in a shop setting.

Panel outside the building? What reason is there for that?

 

[hell_fish_65]

Whole new loop!

 

[hell_fish_65]

Panel outside the building? What reason is there for that?

Lack of interior wall space.

 

[PAToyota]

Seriously? A panel isn't that big... I'd be more concerned about access to it if it were outside. And not even sure about the code issues with that. Panels are normally weather tight so you'd probably have to put it into an external-rated box of some sort - which is going to get pricey...

 

[hell_fish_65]

It would be the same as my house. Its box is outside too.

 

[PAToyota]

Just surprised me - you don't see that around here. If you have to reset a breaker in your house you have to go around outside to do it? Is it locked? Around here, the neighborhood kids would have endless fun turning things off inside your house if the panel was outside...

 

[Charles (in GA)]

There are Raintite rated breaker panels for outside use (3R I think) but yes, they would be pricey. More common in the West I think.

Charles

 

[wildo]

I have a couple thoughts on your plans:

1) On your outside receps- use 12/3 w/g and alternate every other outlet. This will put every other outlet on a breaker. To me- that makes more sense then one feed per side.

2) I REALLY think you should alternate your power to the lights. In the provided drawings- your main switch will turn on light to only one side of the building. If you ran power to the bottom-right, top-second from the right, bottom-third from the right, etc... (if that makes sense) Then, when you flip on the switch you have even light on all sides of the ship. If you need more- you just flip the other switch....

hope this helps!

 

[hell_fish_65]

Just surprised me - you don't see that around here. If you have to reset a breaker in your house you have to go around outside to do it? Is it locked? Around here, the neighborhood kids would have endless fun turning things off inside your house if the panel was outside...

I live on 7 acres in the country. neighberhood kids don't tent to venture much out of there own yards. And, yes, I have to go outside to reset if needed. I am planning on attaching a car port to the side of the shop where the box will be hung.

 

[hell_fish_65]

I have a couple thoughts on your plans:

1) On your outside receps- use 12/3 w/g and alternate every other outlet. This will put every other outlet on a breaker. To me- that makes more sense then one feed per side.

I am using 12/2, How do you wire a outlet with a 4 wire(12/3) run? I have been wondering what its used for.

 

[wildo]

I am using 12/2, How do you wire a outlet with a 4 wire(12/3) run? I have been wondering what its used for.

The having the third wire just makes it easier on install. For every other box, the third (red) wire won't be touched. For the opposite boxes, though- you would use the red wire as your hot and the black wire wouldn't be touched.

When I say "wouldn't be touched" I mean that it isn't hooked to anything. Just wire-nut it to itself.

A typical install for receptacles would be like this:
=========================
boxes 1, 3, 5, 7 etc...

• black wires to gold terminals
• white wires to silver terminals
• ground wire to green terminal
• red wire to outbound red wire

boxes 2, 4, 6, 8 etc...

• red wires to gold terminals
• white wires to silver terminals
• ground wires to green terminal
• black wire to outbound black wire

at breaker...

• red wire to a breaker
• black wire to a breaker
• white to a ground bar
• ground to a ground bar

So you can see, you are effectively alternating every other recept on the two breaker runs, but you don't have to run two separate 12/2 w/g runs. This means that you save 2 conductors x length of run. With the price of copper how it is now... it might be worth thinking about.

One last point- The reason I suggest this is because now every other recept would have the capacity for 20A (or whatever). If adjacent recepts were on the same breaker run- then the two power tools plugged into each would both only have access to 20A. Granted you will not likely run into a situation like that, but why not plan for the future? Perhaps a table saw plugged into one and a dust collector in an adjacent one... it starts to add up.

Just my $.02

 

[W-Cummins]

at breaker...

• red wire to a breaker
• black wire to a breaker
• white to a ground bar
• ground to a ground bar

You MUST attach this circuit to 2 poles of either a 240v breaker ( best way) or 2 single pole breakers on different legs of the 240v bus. And most places you also need to tie the switch levers so that there is a common trip and/or shut off of your Edison circuit. If you do not wire it this way you will overload the grounded conductor if you operate the circuit at over 10 amps on each leg.

William...

 

[wildo]

Yes, I am sorry I forgot to mention this... If you put the red wire to a breaker on the left side of the box, and the black wire to a breaker on the right side of the box, then you should be fine.

 

[kavic]

This is my first post on this forum, but I just got my permit to rewire my 20' x 20' two car garage and agree that you might want to consider more outlets. In my garage, I have 20A outlets every 2' all the way around at a height of 4' and 1' from the ground. I also agree wth running 12ga wire in everything for future expansion.

Even thought the left area will be used for storage right now, I'd still add 3-4 lights in that area. Here's my wiring diagram for reference.

You are going to love doing this project. I know I have

 

[wildo]

In order to not give bad advice... I did just a bit more research on the Edison Circuit. My last post said to use two seperate breakers on opposite sides of the box. While this will work, it is not a good practice. Wikipedia makes a good point about this:
__________________________________________________
Double and triple breakers for shared neutral:
In order to avoid the danger of having breakers later re-arranged onto the same leg (which would create a potential overcurrent hazard), shared neutral circuits should be connected to multigang breakers rather than to separate single gang breakers.

Common trip on shared neutral circuits
Common trip is always required if there are loads that use more than one phase simultaneously.

In situations where there are only single-ended loads, common trip is still generally advisable for the following reasons:

An inexperienced user might only check one of the sockets and think the circuit is off when turning off only one breaker, i.e. a homeowner might go into the kitchen, plug in a lamp, and turn off breakers until the lamp goes off, not realizing that the two duplexes of the duplex receptacle are fed from different breakers. Subsequent electrocution could result; Loop currents could be present, when someone is working on the equipment, or otherwise.

 

[Lloydthumper]

This is my first post on this forum, but I just got my permit to rewire my 20' x 20' two car garage and agree that you might want to consider more outlets. In my garage, I have 20A outlets every 2' all the way around at a height of 4' and 1' from the ground. I also agree wth running 12ga wire in everything for future expansion.

Even thought the left area will be used for storage right now, I'd still add 3-4 lights in that area. Here's my wiring diagram for reference.

You are going to love doing this project. I know I have

Depending on where you live sometimes it is best not to have to many breakers when getting it inspected. It is not required to have outlets in a garage by code here. I figuare that is just more for the inspector to look at to fail it on. just my opinion I put up 4 before my inspection but I have a total of 12 to put in later.

 

[kavic]

The inspectors here are pretty cool. I had a licensed electrician help me design the circuit before starting. He also came by yesterday to check everything before I went to city hall to get the permit. Should be o.k. for the inspection.

Thanks

 

[RacerX]

I've been following along on this thread and am wondering what programs you are using for your electrical drawings? They look great and I'm getting ready to do a garage construction of my own. I have the architect drawings, but want a more elaborate drawing like above.

Curtis

 

[hell_fish_65]

I just used MS paint.

 

[kavic]

I've been following along on this thread and am wondering what programs you are using for your electrical drawings? They look great and I'm getting ready to do a garage construction of my own. I have the architect drawings, but want a more elaborate drawing like above.

Curtis

Thanks. I used MSPowerpoint and saved the screen shot as a .jpeg with MS Paint. I usually use Solidworks or Autocad for this kind of thing, but I drew this up at work .

 

[RoyB]

first post here.

I am an electrician from chicago, so I am not familiar with local codes out that way, but Chicago code goes by national code i believe.

a garage only requires 1 outlet. it is supposed to be GFI protected as well. inside the house it is required to have an outlet every 12 feet (6 foot from an entry door in either direction).

personally i have never seen any panels outside, but im sure they exist. ive only seen disconnects outside. nema type 3 is outdoor use.

i would stay with siemens as their equipment tends to be better than most on the market. costs a little more, but you get what you pay for.

i would add lights to the left of the drawing, and like the previous person said, alternate the circuits next to each other. also, as previously state, if you use 3 wire, your two circuits need to be opposite each other on different phases. you do not need to use a double breaker. you need to be careful when working with circuits like that. if you disconnect the neutral and still have the other breaker/s on, then you can get 220 to an outlet and fry whatever you have plugged in. always hook the neutral up first and unhook it last.

and if it were me, id add 3-way switches by the other door...or atleast 1 to turn some lights on.

also might want to consider and exhaust fan with c/o sensor as long as ur at it

 

[shocksystems]

first post here.
also might want to consider and exhaust fan with c/o sensor as long as ur at it

That seems like a great idea. Anyone else do this?

Cheers!

Jim

 

[hell_fish_65]

Thats another question I have... CFI, where should they be placed? At least one per series, if I remember right. The 2nd door only goes to the pond and will rarely be used and never at night.

 

[RoyB]

you can put a gfi at the beginning of the series (per circuit). then "load" side the rest of them off of that one and you are set.