How many 1" breakers do I really need?

[Jim O'Dell]

a 100 amp breaker box is sufficient in most cases. i run a business off the 100 amp box and doubt ill fill the box. plenty room.

on a seperate building with a 200 amp box i would drop a separate meter in....jack

Jack, this building came already set up this way!! Separate power line from the pole, separate meter. Only bad thing is I won't be able to hide how much electricity I use ;-)).

Jim B., I think I remember you talking about junction boxes in another thread a while back. I had considered that until I got the great deal on the 10-3 w/ground that the local HD had left over when they moved. I got what was left on the roll at 75% off. That's when I decided I had enough wire to do home runs to everything. If I need to double up later, I plan on leaving a little slack where I can cut, install a J box, and split off as needed.

Mike, if I was buying the wire at full price, or anything close to it, I would do just as you suggest. But the wire is here, and it was CHEAP!!

Speaking of cheap, (it's that Scottish blood from my Mom's side of the family), the reason I started questioning how many slots I really need is I started adding up the price of the SD 200 amp box, then adding all the breakers. I'm at about 350 to 400 bucks. I need to go back and look at the GE unit HD has. I did see that it says it has copper bus bars. If it has 30 slots and I can save a bundle, it might be worth it. The load center for the house is a GE...might even be able to swap breakers in a pinch if needed.

one more question if I may...most 220 circuits should be 30 amp I'm guessing. The cyclone is the Clear Vue with the Leeson 5hp (3 hp continuous) motor. I have the MM E 16 Bandsaw with the 2.5 hp motor, plan on a 60 gallon compressor that will be rated at about 13 at 90 psi, hope one day to get a 3 hp cab saw (have a Ridgid 1.5 hp contractor saw now), and 6 or 8" jointer. The drill press may or may not get wired to 220 (Delta 17-965), the PTAC I'll eventually put in might need 40 amp, but probably not. Then there is the welder (small unit) I'm sure 30 amp is adequate for this. Anyone see any flaws in this thinking? Thanks again. Jim

[Steve Cox]

All my 220V circuits are 20A. I am using a Jet 3hp cabinet saw, Powermatic 8" jointer, Rockwell 2hp 13" planer, Laguna 16" bandsaw, CH 60gal compressor, Woodsucker 2hp cyclone, and hope to use a 3hp shaper in the future. All of these run on 20A circuits with no problem.

[Peter Mc Mahon]

Hello Jim. I have a Siemens panel and there are double breakers available for it. It is 2 110 breakers [15amp] that fit into a single space. This effectively doubles all of your 110 spots. Peter

[Randy Meijer]

...In the main panel I have seperate circuits for the lights (110V 20A), heater (220V 30A), and I left the garage door on its' original circuit...

Not exactly sure what Steve is telling us; but would like to make the point that "TWO" light circuits would be a prudent move. Should you be right in the middle of a milling process and have the light circuit trip and loose "ALL" of your lighting, it would be a very dangerous situation!!!!! With your lights on 2 different circuits, hopefully you would never be totally in the dark with other machinery still running.

[Randy Meijer]

...Randy, I'm thinking about using the GFCI outlets instead. Correct me if I'm wrong, but I seem to remember that if a GFCI outlet is the first in the chain of outlets, that all are GFCI covered?? If this isn't true, I may have to rethink the breaker issue. Also, a question on code....I live in an uncorporated area, at least so far. Anyone know who I would contact for what codes I should be following? Just use NEC?? Who do I call for electrical inspection before I can have power hooked back up....

Jim:


For 120V outlets, what you are remembering is correct. The GFCI does not have to be the first outlet in the circuit; but if it is not, then only the GFCI outlet and any "downstream outlets" will be protected.


I have never wired any 220V circuits with GFCIs so I can't advise as to specifics. Since GFCIs work by comparing amperage in the hot and neutral legs of the circuit, I don't know how that applies to 220V circuits since you have 2 hot legs and no neutral. You probably need to search out some additional info about GFCIs installed on 220 circuits or maybe some SMC member knows the answer.


Here in Texas, building permits are issued by a county office for construction in unincorporated areas unless you are in the ETJ of a city. I assume your local government has a similar structure. I'm sure that someone in that office could inform you of the necessary requirements. Good luck!!!

[Tony Falotico]

Not exactly sure what Steve is telling us; but would like to make the point that "TWO" light circuits would be a prudent move. Should you be right in the middle of a milling process and have the light circuit trip and loose "ALL" of your lighting, it would be a very dangerous situation!!!!! With your lights on 2 different circuits, hopefully you would never be totally in the dark with other machinery still running.

Agree with Randy on this one, I alternated my lights on two circuits with two separate switches for the reasons Randy stated.

[Jim Becker]

Since GFCIs work by comparing amperage in the hot and neutral legs of the circuit, I don't know how that applies to 220V circuits since you have 2 hot legs and no neutral.

240v GFCI is done at the breaker...there is an extra lead that gets installed in the breaker box.

[Steve Cox]

It seems that many people are installing lights on two circuits but I don't understand why. Yes the idea of lights never going out while milling something is a good idea, but please tell me what would cause the lights to go out. Circuits pop when you have an over current situation. If the lights are on, and the circuit is not permanently overloaded (too many lights) what will cause them to go out? The only thing I can think of is a short in one of the lights or the wire going to it and that is an extremely rare circumstance. I can live with that risk. If there is something that causes the whole panel to blow then whatever tool you're working on will stop as well. The point of the circuit being in the main panel in my original post was that the sub that controls all the outlets could turned off and locked as a safety measure for my kids but the lights and heat still work in the shop.

[Jim O'Dell]

I was watching an e-bay listing on a Square D 30/40 200 amp outdoor box, starting bid placed at 49.99. Figuring it would go up, I was looking to see if anyone else was bidding on it, and found the seller had the same box, but the indoor model starting bid 49.99, buy it now 49.99, so I jumped. These don't come with the main breaker, but I had already e-mailed the seller and he has them for 60.00. Both box and main are new, sealed in the box. I think I did alright. 30 slots should be plenty, and if needed, I could add some 1/2" slots to gain some. I also won a bid the other day for 5 - 220volt, 30 amp breakers (used) for 14.99 total plus shiping, and 6 new leviton 120 volt GFCI for 31.00 plus shipping. Now to find some more breakers, and some regular outlets!!!! Jim.

edit: Where are my manners?? I meant to add that I appreciate all the information passed along to me on this thread. I went back looking for who mentioned e-bay to me, may have been on another thread, and couldn't find you, but THANKS for reminding about this resource. On this one project alone, it has already saved me a bundle!!

[Chris Padilla]

Guys,

If you plan to wire in 120 V GFCI, just remember that in a mulitwire situation (i.e. you bring in 2 hots (red and black) and a neutral (white) and ground (green/bare)), each GFCI needs its own neutral. So in this situation, you would need two neutrals. This nearly bit me but thank goodness I put in mostly flex conduit...wasn't too bad to pull a second neutral.

[Jim O'Dell]

Guys,

If you plan to wire in 120 V GFCI, just remember that in a mulitwire situation (i.e. you bring in 2 hots (red and black) and a neutral (white) and ground (green/bare)), each GFCI needs its own neutral. So in this situation, you would need two neutrals. This nearly bit me but thank goodness I put in mostly flex conduit...wasn't too bad to pull a second neutral.

I'm lost, Chris. Are you talking about multi wiring through a conduit that would do multiple 110v circuits? I plan on running 4 individual 110v circuits for outlets, and a few task lights. 2 separate 110v circuits for the main lighting. I will put 1 GFCI at the start of each 110v circuit so that it protects everything down stream, each circuit should have it's own neutral, using 12/2 with ground for the 110 wiring, right? I doubt that I'll do GFCI for the 220v circuits, seeing that I just purchased 5 220v breakers that are not GFCI :-0. Jim.

[Chris Padilla]

I'm lost, Chris. Are you talking about multi wiring through a conduit that would do multiple 110v circuits?

More or less, that is correct. Say per box, you want two 120 V duplex outlets but you want each outlet on a different breaker or circuit. In a non-GFCI situation, you would just run 4 wires: black, red, neutral, green/bare (any romex XX/3)-->this is known as multi-wiring. However, if you want to GFCI protect both of those circuits, you would need to run TWO neutrals...you can't share the neutral if you want both circuits protected by a GFCI! You would need some romex XX/4 or pull a second neutral through the conduit.

I don't have any GFCI protection on my 240 V stuff either...only 120 V stuff.

[Ken Fitzgerald]

Jim.....Chris is talking about "Edison" wiring 120 v outlets. In my shop 2 120v circuits go down each wall. Everyother outlet is on say "circuit A" and the next outlet is on "circuit B". You can wire this type of arrange by running 2 12-2 circuits or using what referred to as "Edison" circuits using 1 12-3. The problem arises when you try to put GFCI in to protect the circuits. In my case I had suspicians that GFCI's wouldn't operate properly with the Edison wiring so I ran 2 circuits using 2 12-2s and each circuit has the first "outlet" as a GFCI outlet. Chris used the Edison wiring idea and ran a single 10-3 or 12-3. The trouble is that GFCI's measure the current difference between the hot lead and the neutral lead. If the is a measureable difference, the GFCI trips thinking something is taking current to ground and not back through the neutral. With the Edison concept using a single 3 conductor cable to provide 2 circuits, the 2 circuits using a common neutral and therefore the GFCIs see a difference in currents if something is operating on one circuit and not the other.......in other words, the GFCI works properly but the circuit won't if you use the Edison concerpt. Thanks Chris for proving my theory and justifying the increased installation costs ..........my local inspector advised me to use the Edison concept!

[Jim O'Dell]

Thanks Chris, I thought that is what you meant, but wanted clarification in case I wasn't understanding. Ken, I'm with you, I already planned to wire with separate 12/2 w gnd wiring. I won't have any multiple circuits in one box, so even though I didn't know anything about 'Edison' wiring, I would probably not have gone that direction anyway. But conventional wiring makes easier sense to me. Thanks for the info. This place is always an education. Jim