Electrical question

[sunsethunter]

Hopefully someone that is smarter than I am is up at this hour. I'm wiring a mini split AC unit at the cabin. 220 from the cabin has a black, white and bare copper. The whip connecting the unit has black, red and green. How do I connect them?

[Terran28]

you cannot!!! From the breaker box, you will need a double pole breaker in the amount required by the manufacturer of the unit, the proper gauge wire ran to the unit in to a disconnect box. The wires ran would be red and black with a ground. You CANNOT connect the red and black wires to the black and white wires of the cabin. If someone installed white and black wires to a 240 volt circuit, they are WRONG and will get someone seriously hurt or killed.

[sunsethunter]

you cannot!!! From the breaker box, you will need a double pole breaker in the amount required by the manufacturer of the unit, the proper gauge wire ran to the unit in to a disconnect box. The wires ran would be red and black with a ground. You CANNOT connect the red and black wires to the black and white wires of the cabin. If someone installed white and black wires to a 240 volt circuit, they are WRONG and will get someone seriously hurt or killed.

There is a double pole breaker in the box. I'm just confused by the wire colors and don't want to screw it up

[Terran28]

call me with what you see. . Terran

[WTucker]

For a 240 volt circuit that doesn’t need a neutral, it’s very common to run a romex with black, white, and bare. I am making the assumption this is what you have. If so, connect black to black, white to red, and bare to green. This is not going to kill anyone, again it’s very common/normal.

[sunsethunter]

For a 240 volt circuit that doesn’t need a neutral, it’s very common to run a romex with black, white, and bare. I am making the assumption this is what you have. If so, connect black to black, white to red, and bare to green. This is not going to kill anyone, again it’s very common/normal.

Got it. I got some step by step instructions and think I'll be good to go. Electricity surely isn't my thing

[Rubi513]

you cannot!!! From the breaker box, you will need a double pole breaker in the amount required by the manufacturer of the unit, the proper gauge wire ran to the unit in to a disconnect box. The wires ran would be red and black with a ground. You CANNOT connect the red and black wires to the black and white wires of the cabin. If someone installed white and black wires to a 240 volt circuit, they are WRONG and will get someone seriously hurt or killed.

Lol!
I assume you aren’t an electrician?

[Terran28]

No, I am not. I have worked with my dad in HVAC for 30 years. Never have I EVER seen a 240 volt circuit use white/black/bare. I did research it and found no codes that state you cannot, however this is asinine and should have codes for it. If I see white/black, that is a 120 volt circuit. I will use my voltmeter to determine voltage, but If I see 240v running through black/white, I will walk away from it and tell them to get someone else or have an electrician rewire it with the proper 12/3 or 10/3 depending on load.

[PEC]

you cannot!!! From the breaker box, you will need a double pole breaker in the amount required by the manufacturer of the unit, the proper gauge wire ran to the unit in to a disconnect box. The wires ran would be red and black with a ground. You CANNOT connect the red and black wires to the black and white wires of the cabin. If someone installed white and black wires to a 240 volt circuit, they are WRONG and will get someone seriously hurt or killed.

OK we are going to need some explanation...
1.What is the difference between red, black, ground or black, white, ground?
2. What if I don't use romex and pull in 3 single blacks? Will it explode?
3. What if we up grade and install (6/3 with a ground), what do we do with the 4th wire?
4. What if I connect red to black, black to white and green to bare?

[Terran28]

1. Red = load, black = load, white = neutral, green or bare is ground
2. 3 single black wires are all loads of a 3 phase circuit
3. You don't use the other wire, you wrap it around the rest (like I have seen every single time or cut it off)
4. If it is a splice , then you used the wrong first wire and should rerun with the properly colored wires. Other than that I do not understand your question.

Edit on 4. You can wire it like that and the circuit will work, however as I stated, if I see white, that is a neutral, always has been and have NEVER seen 14/2, 12/2, or 10/2 used ever in a 240v circuit

[Terran28]

Guys, I understand my first comment to the OP was wrong in the eyes of electricians, but just stating I have never seen that (and until i just researched, thought it was wrong). I was taught differently by my dad. You be courteous to the "other guy" and use properly color coded wires to distinguish the circuit. If you HAVE to use different colored wires, you wrap tape around the ends of the wire to let them know it is a load bearing wire (black or red tape).

I have heard of technicians walking away from jobs because of this. They didn't want to become the liability because someone assumed that the white wire was a neutral.

[Rubi513]

In residential work, you will see far more white conductors used for 240v than you will see red. Yes, it should be wrapped in tape to indicate it’s a hot.

If an electrician used “12/3 or 10/3” for a 240v load that didn’t require a neutral, he was throwing money away...

[Terran28]

In residential work, you will see far more white conductors used for 240v than you will see red. Yes, it should be wrapped in tape to indicate it’s a hot.

If an electrician used “12/3 or 10/3” for a 240v load that didn’t require a neutral, he was throwing money away...

Every single residential 240v circuit I have seen has had the red wire it it. And the issue I see with that is if they reduced it back to 120 volt, then they have the black load line and the bare ground as neutral and the white line capped off...

[panhandlehunter]

Every single residential 240v circuit I have seen has had the red wire it it. And the issue I see with that is if they reduced it back to 120 volt, then they have the black load line and the bare ground as neutral and the white line capped off...

Well you learned something new. Never assume black/white=120V. I’m surprised you have never seen it, I would bet money it is that way on just about every house.

[Rubi513]

Every single residential 240v circuit I have seen has had the red wire it it. And the issue I see with that is if they reduced it back to 120 volt, then they have the black load line and the bare ground as neutral and the white line capped off...

Then you haven’t done much residential work.
So, you’re ok with someone using a bare ground as a neutral?