Overpowered circuit?

[Chaghatai]

In my detached garage there are two 20 amp breakers labled "heater". I found a run of romex supplying the heater and after shutting everything off, I spliced into it. So far so good, my outlet has power.

First thing that is odd is that even though I'm in a single wire, both breakers must be on for this circuit to work, so somehow it's wired into both. I'd think 240, but there's no red wire.

Here's the real problem: I plugged my chiller into it and it's fan ran real hard - much faster than normal. It was very loud. That and the compressor wouldn't turn on - when it did, it would run for like one second than it's internal protection switches and it turns off. I plugged it into another circuit and it ran fine. I plugged an incandescant into the suspect switch and it blew instantly.

I've got experience with the basics, I ran ordinary circuits in a small addition one time, but I'm no electrician and this has me stumped.

Any help is appreciated.

 

[00420]

the 2 20 amp breakers is 240volt.... and so is your "heater"

your chiller is not.... and when you wired your plug in you tapped the 240 lines and hooked them up 120 thre for you have 2 hot's on your 120 plug....

for your "heater" there should be 4 wire's
1 red
1 black
1 white
1 green or bare

what you need to do for a 120 line is run
1 red or black ( pick one ) the other should not be used unless you run a 2nd 120 plug of it to......
1 white
1 bare/green

edit i just reread....
theres no red.... they more then likely ran 2 120 (240) for your heater using
2 blacks (1 as red )
2 whites (tied together as one)
2 bare's

look and see how its hooked up to your "heater" and how its hooked up to your power box....

 

[Chaghatai]

That's what I thought at first, but no red wire - I wonder if further upstream both hots are plugged into the same run of romex - that wouldn't make any sense though if it's heading to a 240 appliance - I must be missing something.

Could the dillhole who wired the garage have ran two circuits into a 120 romex, then splits the hot to wire it into the heater? I'd have to take a wall apart to get to the heater's wiring though and see how it's wired.

 

[00420]

That's what I thought at first, but no red wire - I wonder if further upstream both hots are plugged into the same run of romex - that wouldn't make any sense though if it's heading to a 240 appliance - I must be missing something.

i just edited my post reread hahaha

and again i would go relook how its wired at both ends......

 

[Chaghatai]

I wish it were as simple as defeating one of the circuits. I'd hate to open the breaker, but looks like I may have to.

 

[Chaghatai]

So it's 10 gauge romex running straight into the breaker on that end. I haven't opened it up yet though. I suspect the guy who set this up was an idiot and didn't have 240 wire. When he realized that he bought 120 wiring, he said "fuck it" and spliced both ends of the black wire... So it looks like I'm gonna have to shut off the garage upstream and unhook one of the circuits.

So again, am I missing something, or does it look like time to attack the breaker?

 

[Chaghatai]

Further researcher reveals that the original wiring may be correct. Apparently in 220, where there's no need to 110, it's common to use cable w/o red wire and run the black and white to each hot. So instead of "neautral" my white is also hot. I think that's what I'm dealing with here.

 

[Chaghatai]

From another forum:

"First things first. How many wires are in that box. You will need a bare or green wire, a white wire and 2 blacks or a black and red. If you dont have 4 wires...you cannot have the option of 2 110 volt circuits. If you have black, white and bare/green wires, you will need to go to the breaker box and remove the white wire from the breaker and put in with the other white wires. This makes your 220 outlet only 110. Now you can run conduit up the wall and up over the roof. YOu need to have a 10' overhead clearance for safety. "

Looks like I have my answer. It's 220. I hope this helps someone else.

 

[00420]

yep...

that is common in older house....

i even see growers do it a lot for the fact that its cheaper 10/2 when they should be buying 10/3.... hope all go's well chaghatai just remember 240 is just 2 x 120 sharing a common......... take one hot off and add the common and your golden

 

[PharmaCan]

Further researcher reveals that the original wiring may be correct. Apparently in 220, where there's no need to 110, it's common to use cable w/o red wire and run the black and white to each hot. So instead of "neautral" my white is also hot. I think that's what I'm dealing with here.

This is exactly what you are dealing with - black and white wires, two hots, no neutral. A very common heater intallation.

If you have a subpanel in your garage, is there room for another breaker?

PC

 

[PharmaCan]

the 2 20 amp breakers is 240volt.... and so is your "heater"

your chiller is not.... and when you wired your plug in you tapped the 240 lines and hooked them up 120 thre for you have 2 hot's on your 120 plug....

for your "heater" there should be 4 wire's
1 red
1 black
1 white
1 green or bare

what you need to do for a 120 line is run
1 red or black ( pick one ) the other should not be used unless you run a 2nd 120 plug of it to......
1 white
1 bare/green

edit i just reread....
theres no red.... they more then likely ran 2 120 (240) for your heater using
2 blacks (1 as red )
2 whites (tied together as one)
2 bare's

look and see how its hooked up to your "heater" and how its hooked up to your power box....

Dude, I've been admiring your flip-flop diy and you do really nice work. But what you wrote above really doesn't apply here. To an electrician, the OP's problem is obvious from the git-go. No offense, but ya need to read these electrical questions carefully and, if you don't really know the answer, say nothing. Electricity can kill people, no need putting anyone in danger.

Again, love your diy on the flip-flop.

PC