220v receptacle problems

[Justin DiValentino]

Let me start by saying I've wired countless 120v circuits/lights/rec, etc.

I just got done with my first 220v receptacle and its not working. I am using a standard NEMA 6-20 250v 20a receptacle. I wired it using 12-2WG wire using the white and black lines as hot and ground being ground. It feeds from the box through a 2-pole 20a THQP breaker.

It is wired exactly like this;



Now, I dont have a big fancy multimeter, but I do have something that looks like this;



When I test across the two hot lines, I get nothing.

Im hoping this is something obvious that Ive overlooked and the collective wisdom of SMC will have my new jointer up and running in no time

[Bruce Wrenn]

Looking at same type of recpt, ground is the upper left screw (green.) Looks like you have hot (black) and ground reversed.

[Justin DiValentino]

Looking at same type of recpt, ground is the upper left screw (green.) Looks like you have hot (black) and ground reversed.

I do have it wired that way, the picture is slightly off from my actual recpt. I shouldve been more specific in the original post

[John Coloccia]

It's impossible to wire that outlet in a way that won't give you at least 120V between any 2 holes. Has the breaker tripped?

[Justin DiValentino]

breaker has not tripped. I've never seen it happen but could it just be a bad breaker?

[Bob Cooper]

if it were me i'd
- first, verify my meter worked as expected -- across 220 at the input to the panel
- if that worked, verify the breaker isn't tripped and then touch the output of the breaker -- unhook the recepticle if you want

[Jim Terrill]

Across the two hot lines?

As in hot to hot?

What about hot to ground?

Haven't used that type of meter before, but when I set mine up, I tested each hot side separately to the ground.

[John Coloccia]

Well, anything's possible. I don't know how comfortable you are poking around inside the panel, and if you're not then don't do this, but you could check and see if you're getting 220 at the breaker screws. That would at least isolate the problem to the breaker, the panel or not being inserted properly.

[Justin DiValentino]

OK just went down and checked, Im getting 120v from each hot line to the ground. Nothing between the two hot lines (though i dont know if Im supposed to) either way the jointer is not firing up and I have nothing else 220v to test it.

[Thomas Hotchkin]

Justin
Have you tested your tester on another circuit that you know is good? Have you checked for power at circuit breaker? At the bottom of some circuit breaker panels both bus bars do not end at the same length, and a double pole breaker end up with both feeds from the same bus bar. If all is good try resetting breaker a couple times or replace it. Tom

[John Coloccia]

OK just went down and checked, Im getting 120v from each hot line to the ground. Nothing between the two hot lines (though i dont know if Im supposed to) either way the jointer is not firing up and I have nothing else 220v to test it.

Sounds like somehow you have managed to get 2 of the same leg to the switch instead of two different legs. You are using a ganged breaker and not just two separate breakers, right?

[John Coloccia]

Aren't THQP breakers the thin breakers? I believe they only use one leg but give you two circuits. I think there's your problem. This is the double breaker that fits into one slot, right? To get 220, you need to take up two slots. Adjacent slots are on separate legs. It's not enough to have 2 wires that are on the same leg.

[Jason Roehl]

Aren't THQP breakers the thin breakers? I believe they only use one leg but give you two circuits. I think there's your problem. This is the double breaker that fits into one slot, right? To get 220, you need to take up two slots. Adjacent slots are on separate legs. It's not enough to have 2 wires that are on the same leg.

Yes they are--THQP breakers are two-pole breakers (can hold two separate circuits), but share the same (single) input leg. For 240V, you need the input of both legs of a typical residential service, which takes a double-height breaker with the trips for the two legs bonded together in some way, shape or form. You need a breaker that looks like the magnified one in your picture above.

http://www.geindustrial.com/publibra...al|DET-089|PDF

[Justin DiValentino]

Problem solved, thank you john. What I didn't know until now is that in order to get 220 you need 110 from each leg. The box is setup with two slots from each leg alternating as you move down the each bus bar. So all it took was moving the beaker down one slot, meter read 220, and I fired up my new (to me) 8" grizzly jointer almost waking up my wife and infant son.

Worth it, thanks gentlemen

[Jim Terrill]

http://www.doityourself.com/forum/el...le-pole.html#b

This implies that the double pole thin breakers work but only in certain slots where they get both buses. Someone posted a link with pics that make sense.