Wiring a 220V circuit breaker

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  #1  
Old 12-10-05, 08:42 AM
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Wiring a 220V circuit breaker

I need to wire a 2 gang double pole 220V 30A circuit breaker. Can I use 10-2 wire? In the service panel, the ground will go to the ground bar. The black will go to one screw on the breaker AND the white (acting as the other hot) going to the other screw. Will this work, OR do I need to use 10-3? TKS!!!
 
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Old 12-10-05, 08:50 AM
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10/2 is good enough for the breaker. Whether it's good enough for the load remains in question since you didn't say what the load is. For example, 10/2 is okay for a water heater, but not okay for a clothes dryer.

If you use 10/2, use a black marker to color both ends of the insulation on the white wire.
 
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Old 12-10-05, 08:51 AM
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The wire required, 10-2 or 10-3 depends on whats at the other end of the circuit, water heater, ac unit, dryer, etc
 
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Old 12-10-05, 09:03 AM
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thanks for the fast response...I'll explain...

I'm rewiring an old workshop. Every outlet will be for a power tool (ie, band saw, joiner, planer, router, etc). There will be no a/c, no dryer, no fridge.

thks
 
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Old 12-10-05, 09:14 AM
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You are probably not allowed to put any of these things on a 30-amp breaker. You can only install 30-amp receptacles on a 30-amp circuit, and it's unlikely that any of these tools comes with a 30-amp plug, and you're not allowed to change the plug.

Check the electrical specifications of these tools, and check to see what kind of plug they have. Then install a circuit to match. You may need to install two 20-amp circuits instead of one 30-amp circuit.

Most likely, assuming that all of these are 240-volt tools and not 120-volt tools, all of these tools can do with a black/white cable, and none require a black/red/white cable.
 
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Old 12-10-05, 09:23 AM
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It became apparent in one of your other posts that your tools are 120-volt tools. In this case, you plan has many flaws.

Is it your intent to install a multiwire circuit? If so, you need 12/3 and a 20-amp double-pole breaker. If you are not installing multiwire circuits, you need single-pole breakers and 12/2.
 
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Old 12-10-05, 09:23 AM
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For my recepticles...my first circuit has 5 outlets. The amperage of these tools for these outlets are 12.5A, (open), 13A, 15A, and 7.5A. My second circuit's amperage has 6 outlets; those tools will be 1.8A, (open), 2.5A, 1.5A, 5.0A, and 8.8A. All 11 recepticles are 20A / 125V (again using 10-2 wire). If I use 2 tools on the first circuit together (ie, 12.5A and 13A), won't a 20A circuit breaker trip? That's why I was thinking of using a 30A circuit breaker.
 
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Old 12-10-05, 09:29 AM
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You CANNOT use a 30 amp breaker for a standard 120v receptacle, regardless of what wire you use. You need to use more 20 amp circuits.

Also, how in the world can you use 10/2, on a two-pole breaker to feed 120v receptacles?? It is not possible and IS very dangerous even if you do get it to work!

I agree with John, your plan has many serious flaws. I really suggest you get a few good books on wiring and get the basics down pat before you go ANY further. If you continue to go as you are something or someone is going to get hurt!!
 
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Old 12-10-05, 09:29 AM
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If you really need to run multiple tools simultaneously, think of multiple 20-amp circuits, not 30-amp circuits.
 
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Old 12-10-05, 09:42 AM
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Let's see if I can salvage what I've already done...

I've already pulled my wire (thru conduit) and hooked up my recepticles and plates. Since I've already used 10-2 wire with 20A/125V recepticles, I'll use a 20A circuit breaker. On the same note, I will only run one tool at a time. If I happen to use a second tool on the same circuit, that worst case scenario is the breaker will trip, right?

As far as my original question, I do plan on wiring for 2 220V machines. I will use 10-2 wire with a 30A recepticle and 30A circuit breaker. And last, but not least, I plan on buying a 100A service panel.
 
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Old 12-10-05, 04:02 PM
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Any thoughts on this from anyone? Just wanted to confirm that I can use 10-2 to wire to a 30A 2 gang double pole circuit breaker....tks!
 
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Old 12-10-05, 04:11 PM
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Originally Posted by DrB323
Any thoughts on this from anyone? Just wanted to confirm that I can use 10-2 to wire to a 30A 2 gang double pole circuit breaker....tks!

Your question has already been answered. Of course 10-2 can be used on a 30A breaker. However, the recepticals you have installed on this circuit cannot be fed from a 30 amp breaker. Thus, the question you are asking is pointless.

The ONLY way you can use this circuit as is would be to connect the black wire to a SINGLE pole 20A breaker, the white to the neutral bar, and the bare wire to the ground bar. So the 10 guage wire was a waste.

You would benefit a LOT by stopping your project and reading up before going any further. You've already made mistakes and demonstrated some serious misunderstandings of electrical wiring in this thread. The $6 green book called "Wiring Simplified" would be a good start. You can find it at your local big box store in the electrical section.
 
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Old 12-10-05, 05:13 PM
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Chirk, I think he is asking about this question:
As far as my original question, I do plan on wiring for 2 220V machines. I will use 10-2 wire with a 30A recepticle and 30A circuit breaker. And last, but not least, I plan on buying a 100A service panel.
In this case yes, you can do as planned. 10/2, black and white as hots, bare is the ground.

Now for my concern. What do you have that is 30a/220v ?? Very few power tools will be rated for a 30 amp circuit. A very large single phase table saw maybe.
What two items are you running on 220v?
What is their amperage rating?
 
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Old 12-10-05, 05:34 PM
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Speedy (and others)...sorry for the delay...I had to step away and walk this one off. I really don't want to come across as an incompetent * * *. I have done wiring in the past. I think I have just crossed 2 separate issues. I'd like to rephase so I'm clear. Thank you in advance for being patient with me.

The 2 220V appliances (if you will) are a dust collector and a hanging / ceiling room heater (to be purchased at a later date). The dust coll. tag says this: 24/12, phase 1, 110/220. It might say more, I'm going on memory. This, and the future heater, will be wired with a 30A circuit breaker, along with a 30A recepticle. I'm assuming that the 24/12, implies the 24 part is the FLA (first load amperage (?) or initial start-up?). So, wouldn't the 30A CB be correct? I'll assume that the heater will need to be run on 220V as well. With what I've read, the 10-2 wire will work.

The second issue are my outlets. Yes, I agree that using 10-2 wire was overkill. The outlets are all 20A/125V with 20A CB. There are like 10-12 different shop tools we have. None will be running on the same circuit at the same time. All have "normal" plugs.

Again, I'm sorry for sounding so redundant. Yes, it doesn't take much to confuse me...hence the asking for your help.

Thank you....
 
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Old 12-10-05, 06:52 PM
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If the heater will be electric the 30 amp circuit will likely be adequate.

For the dust collector, the 24/12 are the amperages in relation to the 120/220 voltage. So at 220v it will draw only 12 amps. I would not use a 30 amp breaker or recepetacle for this. The 10/2 is fine, but use a 20 amp receptacle and breaker.
 
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Old 12-10-05, 08:23 PM
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Great...thanks for clearing this up. So bottom line is only 1 30A CB (for the heater). Then all outlets/recepticles will be 20A/125V with 20A CB; except for the dust coll. which will be 20A/250V (20A CB). As far as my lights, I'm running flourescent fixtures which has 15A/120V recepticles. Thanks!
 
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