What is this electrical breaker

[3Ts]

Sorry but I guess I posted somewhat of a trick question. If both wires brought out came from L1, you have just wired a 120v circuit not a 240v one. That逞ｴ the crux of my post on not worrying about picking 2 out of phase hots for a single phase 240v run.

In other words, you can稚 get your 240v any other way.....

Yes, you'd have (qty =2) 120v circuits, BUT! Don't run a single neutral for the combined current on L1 & L2. In the situation you describe, you'd be best running a separate neutral for each hot wire.

 

[k0ua]

That's an understatement. I once worked on a grain bin fan, 120 volt that had one hot wire to it and a bare copper wire stuck in the dirt, it worked.
QUOTE]

Genius! ...fan automatically stops running when it's too dry for ground to conduct current. Automatically turns after a rain & humid conditions. I know nothing about grain bin fans, but isn't that what you want it to do?

A humidity controlled fan, it just doesn't get any better than that.

 

[jaxs]

Sorry but I guess I posted somewhat of a trick question. If both wires brought out came from L1, you have just wired a 120v circuit not a 240v one. That逞ｴ the crux of my post on not worrying about picking 2 out of phase hots for a single phase 240v run.

In other words, you can稚 get your 240v any other way.....

From that line of reason,one of your understudys might have did the installation in question. :laughing:

 

[buckeyefarmer]

That's an understatement. I once worked on a grain bin fan, 120 volt that had one hot wire to it and a bare copper wire stuck in the dirt, it worked.
The farmer liked to have had a heart attacked when he got the bill from when I replaced the single THHN 14 gauge wire laying freely with 50' of new 10 gauge wire in conduit to it to make it all work and replaced the burnt penny under the burnt 5 amp fuse with a new 20 amp fuse. "well why did you replace all that wire, it worked before."

That would be my dad, lol.

 

[Birdhunter1]

A humidity controlled fan, it just doesn't get any better than that.

Surprisingly it always worked.

 

[aczlan]

Yes, you'd have (qty =2) 120v circuits, BUT! Don't run a single neutral for the combined current on L1 & L2. In the situation you describe, you'd be best running a separate neutral for each hot wire.

Incorrect, IF you feed 20 amps of 240v from a double breaker into a 12/3 wire it has 240v from red (hot) to black (hot) and 120v from red or black to white (neutral).
As long as all three wires are 12 gauge that is legal and you can get 120v or 240v out of it.
If you have 12 amps from black to white and 6 Amps from red to white, the white will only be carrying 6 Amps back to the panel.

Aaron Z

 

[PILOON]

A humidity controlled fan, it just doesn't get any better than that.

Hey, I built a 200 ft barn and wired his fans via humidistats as the fans were only needed to control humidity.
His other barn was fan wired to the heaters costing a fortune to extract humidity.

LOL, the horses liked that and the owner's bank book as well.

 

[3Ts]

Incorrect, IF you feed 20 amps of 240v from a double breaker into a 12/3 wire it has 240v from red (hot) to black (hot) and 120v from red or black to white (neutral).
As long as all three wires are 12 gauge that is legal and you can get 120v or 240v out of it.
If you have 12 amps from black to white and 6 Amps from red to white, the white will only be carrying 6 Amps back to the panel.

Aaron Z

What you say is correct, but you misunderstood my comment. Mine was in reply to using 2 single breakers, (which could be on the same phase - or not). If they are not on the same phase (meaning adjacent slots in the panel) then whether you use 2 single breakers (or an even number of spaces between them) or a double breaker, you'll end up with what you describe. However, it the two single breakers have a space (actually an odd number of spaces) between them you only have 2 - 120 v circuits.

The original comment I was replying to was

... If both wires brought out came from L1 ...

which puts both lines on single breakers with a space between them. Your reply is correct for one wire on L1 and the other wire on L2.