Single Phase Power, # 5 Electrical School

[chris45n]

When you wire a 240 volt outlet, many times people refer to the different sides of the breaker box as phases. You are saying this term is slang and both hot wires are on the same phase?

[madisonelectronic]

Hello and thank you. Please educate me why my 240v air conditioner in Chicago takes only two hot wires with no ground ? or neutral?. Thanks. If you have a video I will watch it.

[salahuddinnadeem]

i have a quistion 220v does need a N, G separate and what do we use cable colors

for R,Y,B, means red yellow black or blue Note in american standred and what colors

we use for N, G,

thanks

[softcellelectrical]

@salahuddinnadeem On 240 the only colors you cannot use for the two 120 volt legs is white or green. White is acceptable on a backfeed in the use of 120, but the only time that a neutral (white) is needed in a 240 volt application is when there is a 120 volt step down transformer in the system. Always ground everything with green, or bare wire where code requires it. hope this helps.

[randalusa]

Way to go getting use out of that $19.95 video camera.

[salimkhan007]

I live in Asia we use 240v.it dont work with out neutral. why this man talk about that it dont required neutral

[softcellelectrical]

@salimkhan007 I'll be honest with you. I don't know if your dealing with two 120 volt legs or a 'stinger' which is one line of a voltage exceeding 220 volts. In the US 'stingers' are used in lighting and are a single leg 270 volt line which DOES require a neutral. If you are dealing with a 'stinger' line in Asia then YES you do need a neutral. It's more complex than space allows. Give me more details and I can better answer your question.

Tank you,

John

[PsychoScientist007]

Hey softcell u r doing great job!!!!!!! I'm trying but can't find #6 tutorial. Can u let me know how can I find this one?

[67tr876]

Do they still use 2 phase power today ?

[softcellelectrical]

240 is two 120 volt legs. If your plug is 120 volts then only one side will be hot. If it is 240 then both sides will be hot. Depending on your generator, there may be an automatic GFI safety feature built in that will nor allow your generator to function unless it is A: properly grounded, and B: the neutral is able to complete a circuit with one or both of the hot legs. The ground should be isolated from the load side of the neutral otherwise your GFI will pop and not reset.

[jackfortunato]

I hate electricity! This discussion sheds no light on why I have to ground two of the 4 wires on my generator to make 120 a/c. And then how do I wire a light bulb to it? Aren't both sides of an A/C plug capable of shocking you? So then my generator would shock you if you touched it's case while it was running?

[dondenter]

@jackfortunato

Just do it with the generator. The makers have made it that way.

Only the hot wire, black, can shock you. The lamp will light connected to the hot and ground.

From a 120 v transformer if you connect one of the two wires to earth the other will be the hot one so you can get a shock touching that wire and earth/ground. Either wire can be chosen to be the hot wire.

[kgdangar2]

thanks.....it helps a lot^^