Electrician HELP..

[thepumpguysc]

Hi Guys.. I know this is a stupid question because I've watched countless videos on this but its kickin my azz.
I'm trying to hook up my 240v air compressor..
I have a double pole 30a breaker in the box.. when I test EACH LEG separately, I get 120v ..screw to ground.
BUT when I test ACROSS EACH LEG I get a big fat ZERO..0v.. shouldnt I get 240v..??
Its 2 friggin wires & a Ground.!!!
Same thing w/ the compressor hook up.. Black to existing Black.. White to existing White.. so simple a monkey could do it.. but not me..
I get 120v on each wire touching to ground but 0 across each other..
PLEASE help this idiot out..!!

 

[kenh]

probable cause: both input sides of breaker hooked to the same phase.
Check to see if both breaker input wires are hooked to a single input.
Happened to me once, wired wrong by a "electrician"

 

[Tinkerer]

Service entrance boxes have two bus bars (legs). 120 volts on each and out of phase. No doubt your two lines are on the same bus bar in the box.
You do have a 240 volt breaker and not two separate 120's I hope.
I have seen two 120's used for 240. But they must have a screw with a nut threw the handles joining them together. That is probably code prohibited nowadays. It should be.

 

[thepumpguysc]

Tinker> I have a single 240 breaker..
Ken>> THATS problably the problem.. I had a "Jack-Leg" come & wire in my panel, lights & recept..
I had to kick him to the curb because after 8 days he couldnt figure out WHY the wall switch only works 1/2 the lites.. & HE INSTALLED EVERYTHING..!!
I have his card in my hand but dont wanna call him..
Ken>> do u know how to fix that.. before I call a REAL electrician.??

 

[chroniekon]

Could you post a picture or two

 

[thepumpguysc]

He!! NO.. it takes more than a monkey brain for that.. lol

 

[Delmer]

A picture of the box, and a picture of the source (like the 100 amp breaker in the house panel if it's fed from the house) would help a ton. So both ends of the wires that run supply wire to the shed.

Check the voltage from each leg of your 30 amp breaker to each of the big feed wires, that should figure out what's going on.

Think of this as two 12v batteries wired in series to get 24V (except that in AC, we put the ground in the middle, and make two hot ungrounded wires, and don't start criticizing the analogy)

You do have a two space, double pole, that goes on both bus bars, right? not a single space breaker with two handles?

And you did flip the breaker OFF, then back ON?

 

[Delmer]

OK, no pictures. Just see if you can find 240 on the wires coming into your box, if you can't, see if you can find 240 on the other end of those wires. That's a good start.

This is under a minute of testing if you know the right next step, we might need a few pictures though. If somebody screwed up electrical, all bets are off, like is the cable cut and shorted underground? mixed up wire labels?

 

[thepumpguysc]

I took the panel off the inside house box & tested the dryer breaker.. 240v
I see where the jack-leg mighta screwed up.. the bus bar on each side isnt connected to each other on the Main Disconnect coming IN.. so no matter what i do, I'm not gonna get 240..
I have 120 on each side of the panel..2 bus bars coming down & a ground bar on each side..

 

[Delmer]

The bus bars are definitely NOT supposed to be connected to each other. Kinda hard speculating, if the guy couldn't get it to work, there's no way he cared what the code said, and no guessing what he screwed up.

Hopefully you have 3 (or 4) big wires feeding from the house, and two of those go to either big lugs on the bus bars, or the two terminals of a big breaker. Do you have 240V between those two wires?

 

[thepumpguysc]

No 240v between the 2 term on the main breaker..
I get 120. each touching each 1 independently to ground

 

[Delmer]

0V between the terminals on the main breaker?

Go in the house, or where ever that wire comes from and check the breaker that they feed from in there.

 

[thepumpguysc]

YUP.. its hard to get 240 when all thats feeding it is 120.!! SOB.. gotta call an electrician to re-do the breakers at the sub panel feeding the shop panel.. Gdammit.!!

 

[Delmer]

Just so you're warned. An electrician is probably going to find a lot more wrong than just the way the breaker is hooked up. Might not want to touch any of it without fixing it all, depends on who you call.

 

[thepumpguysc]

Yes, your right.. but its only money.. Lol.
The price of pump overhaules just went up.. Lol
I found the problem but I dont have the running knowledge to fix it..
Just like pump work i guess.. everybody KNOWS whats wrong, they just dont have the running knowledge to fix it.. & THATS WHY there speciality shops.. lol {how many times have i typed that out..lol}

 

[Delmer]

If you found the problem, then you can fix it if you want. This is much simpler than anything inside a pump. It doesn't have to be dangerous if you pay attention and shut stuff off before working on it, and can follow directions.

 

[thepumpguysc]

You would think so.. lol but its blowin my mind..
I "thought maybe" if i run a "jumper wire" from 1 leg of the 240 to 1 leg of the 120, I'll get 240 going to the shop.. so I tried..
KEY WORD is "TRIED".. lets just say its a good thing I have a big pecker... cuz I only blew the tip off.. Lol..
I dont think she'll even notice.!!??
Time to make some calls I guess.??

 

[Delmer]

You did that in the house? you're on the right track, but follow directions a little better next time. Measure the voltage before hooking stuff together. You've got the 120, you need one of those 120's to be hooked to the OTHER 120 so they add up to 240 between them, rather than O volts between them. You shouldn't need a jumper wire, but find out what's wrong before fixing it.

I have no idea how it's hooked up in the house, but we can figure that out easy enough if you want to.

 

[Nige]

It's times like this I love the fact that in the UK 240V single phase is standard power in ALL domestic installations. Appliances, lights, power sockets, makes no difference. An advantage is that it requires smaller diameter cables for the same current draw.
There's none of this 120V to run the lights, power sockets, etc, and 240 to run the stove, dryer, etc. That's just too f'kin complicated.

I just made a bowl of popcorn - you boys crack on .........

 

[Delmer]

Oh yeah, nothing simpler or more foolproof than a ring circuit no way even a stupid american could mess up one of those!

If I want to run three 12 gauge wires to power a 9watt LED light bulb, that's my right as an american.