220v Circuit - Only One Leg Hot

[Ferrino]

I was wondering if someone could please help me with an issue we've had recently with the 220v supply to our electric clothes drier. Suddenly the drier would spin but no heat. I heard this can be cause by the drier only receiving 110v (to turn) and not the full 220v (to heat). Sure enough, when I test the 220v outlet, I get 110v from one leg, but not the other. Is it possible for the 220v breaker to fail in one leg and not the other? I've flipped the breaker on and off a few times and it does not help - can I just pull the breaker and test that both legs can close properly? Other than that, I suppose one of the 110v hot wires could have come loose (from the outlet or breaker end)?

I appreciate any help I can get as I am also considering using this circuit to power an air compressor!

 

[G_P]

It is possible that the breaker failed on one side. Also possible there is a break in the wire somewhere. Check the voltage at the breaker if you have both legs giving 120v then the problem is either the wire or the outlet.

On any chance did half the 120v circuits in your house go dead? Sometimes you lose one leg coming into your house and only have 120v coming in causing all 240v appliances not to work and half of the 120v circuits to go dead.

 

[Ferrino]

Thanks - I will test the breaker! The breaker is unfamiliar to me - it seems to be a dual tandem one, which controls 2 separate 220v circuits. The 2 outer legs of the breaker are for the 30A drier circuit which I am having a problem with and the 2 inner legs of the breaker are for a 50A electric range circuit (which is no longer used as we have a gas range).

No, not been having any problems with other 110V circuits.

As an aside, will this 30A circuit be OK to use to power a 220v air compressor (when not using the drier)? The specs of the compressor are: 230V/15A.

 

[G_P]

Even thought the compressor only draws 15a if you hook it to a 30a breaker you must use 10ga wire. But yes the compressor will run just fine on that 30a circuit. The wire must be sized to the breaker feeding it.

If one leg of the 30a part of the breaker is dead and both legs of the 50a part work DO NOT hook the dryer to the 50a breaker.

 

[Zeke]

The service cord to the compressor using 240v can be 12 ga stranded. Hard wired I'd use the #10. Right about not using the 50A side of the breaker. If the 50A is not in use, get a new 30A double pole breaker and put a blank in the open space or you can add some convenience circuits. You can even add a breaker in the open space and leave it not wired. Might be easier than finding a blank or filler plate.

 

[G_P]

I would replace the 50a with a new breaker for the compressor. This way you dont have the dryer and compressor on the same circuit and can run both at the same time.

 

[Zeke]

I'll bet he has closed walls and is looking for a quick way to use the compressor on 240v and I'll be the panel is outside and around the corner. That is usually the case when folks come on here and ask about dryer outlets (the lack of one leg notwithstanding).

 

[pattenp]

I know people will roll their eyes at me because I'm always spouting off code but the dryer is to have its own circuit all by itself. Don't piggyback off the dryer circuit.

 

[Ferrino]

Yes, the walls are closed, but if I did re-purpose the old 50A circuit (formerly for the electric cooker) for a compressor, the outlet would be right next to the breaker panel, so no big deal hooking it up. I am just exploring all of my options.

Out of interest, why would it be an issue to use the 220v drier circuit for both a drier and a compressor, assuming that I only use one at a time? Presumably this is just for code reasons to stop people doing something silly like running both simultaneously if they keep both connected?

 

[Milton Shaw]

The breaker can be bad internally or it can be bad where it slides on the buss bar in the breaker box. If you can turn the power off, you can remove the breaker and check the bars in the box itself. Then replace the double 50/30 with a 30 am for the dryer/compressor. Buss bars should not be burned or pitted where the breaker was.

 

[Zeke]

Yes, the walls are closed, but if I did re-purpose the old 50A circuit (formerly for the electric cooker) for a compressor, the outlet would be right next to the breaker panel, so no big deal hooking it up. I am just exploring all of my options.

Out of interest, why would it be an issue to use the 220v drier circuit for both a drier and a compressor, assuming that I only use one at a time? Presumably this is just for code reasons to stop people doing something silly like running both simultaneously if they keep both connected?

Of course you are correct about 'silly' people. The code is there so insurance companies have guidelines for claims and because many people would leave this set up behind if they moved. Worse yet is something happens to you and your survivors have no idea.

 

[Mustang51js]

From what I read it's not on the same circuit, he is using a tandom breaker. Just test the breakers and test the wires going to the outlet if breaker is good. It could be a bad outlet but I'm going with a bad breaker. Get a 30-20 tandom breaker. I'm assuming you have a seimans panel or ge since those are only two I remember having breakers like that available

 

[wyliesdiesels]

Yes, the walls are closed, but if I did re-purpose the old 50A circuit (formerly for the electric cooker) for a compressor, the outlet would be right next to the breaker panel, so no big deal hooking it up. I am just exploring all of my options.

Out of interest, why would it be an issue to use the 220v drier circuit for both a drier and a compressor, assuming that I only use one at a time? Presumably this is just for code reasons to stop people doing something silly like running both simultaneously if they keep both connected?

What is the HP rating of the compressor? (*Squawk squawk* for the regulars on here. LoL Im starting to sound like a parrot because ive asked this in so many threads)

 

[Aceman]

Pull the panel cover and test the breaker. If one phase is dead, pull the breaker from the panel and inspect the breaker where it stabs onto the panel buss as well as the buss itself. If everything looks okay, it most likely failed internally. Replace the breaker.

But, if voltage checks out at the breaker, pull the dryer recep from the wall and check the connections on the back of it.

Very few service calls turn out to be a bad wire in the wall. 95% of the time it's a breaker/buss issue or a bad connection at the device.

 

[wyliesdiesels]

Another good question i didnt think of earlier- what brand of panel do u have? If its a Zinsco or FPE then youve got bigger concerns....

 

[Elmo4895]

As stated above it is most likely the breaker. I have found many 220 breakers open on one side, even a couple of brand new ones, mostly GE. I have found on service calls loose screws on breakers and also on the receptacle. One that comes to mind had the insulation chared six inches back from the receptacle and the screw burned completely out of the receptacle. I do not know why no one ever smelled melting plastic, they were lucky it didn't set the wall on fire.

 

[Ferrino]

Thanks all. We're having an A/C system installed next week, so I am going to have the contractor test the breaker in question when he adds the new circuits for the A/C.

The air compressor I am thinking of buying is 3.7hp and draws 15 amps @ 230 volts. It's this one from Lowe's. I like the idea of switching out the existing 30-50 tandem breaker for a 30-20 (30 for drier, 20 for air compressor).

 

[LS6 Tommy]

Link doesn't show the compressor. IDK if I would run a 15A compressor off a 50A breaker, regardless of wire size being rated for 50A. What's the maximum fuse/breaker size listed for it?

Tommy

 

[wyliesdiesels]

Thanks all. We're having an A/C system installed next week, so I am going to have the contractor test the breaker in question when he adds the new circuits for the A/C.

The air compressor I am thinking of buying is 3.7hp and draws 15 amps @ 230 volts. It's this one from Lowe's. I like the idea of switching out the existing 30-50 tandem breaker for a 30-20 (30 for drier, 20 for air compressor).

What is the brand of the electrical panel u have?

 

[sberry]

I ran in to a bad breaker the other day. And in another spot a burned buss where we were unaware there was even a problem, it would have been at some point. Mine were QO.
I agree that this is not a one time event, check the dryer connections and add a circuit for a comp.

 

[theoldwizard1]

Never heard of a 240V tandem. Must look odd bridging the outer handles. Anyone got a picture ?

 

[theoldwizard1]

Yes, the walls are closed, but if I did re-purpose the old 50A circuit (formerly for the electric cooker) for a compressor, ...

I did this on a FUSE panel. I moved the wire out of the kitchen and into the basement. In a J-box I spliced on 12 gauge, using split nuts, and ran it in conduit to an outside weather resistant box and receptacle. Back at the fuse panel I replaced the 50A fuse pair marked "Range", (the box has pull handle/fuse holder wired parallel to the feed for the rest of the panel) and using the appropriate fuse adapters, installed small 20A cartridge fuses.

Weirds people out having a 240V outlet on the outside of the house, but it has worked for 30+ year. Too lazy to dig the trench to the garage, install a load center with breakers in the house and a sub in the garage. "Next year."

 

[wyliesdiesels]

Never heard of a 240V tandem. Must look odd bridging the outer handles. Anyone got a picture ?

Not odd at all. I see em all the time! BElow is one example. Another name is a quad...

 

[AP514]

OP do you own a Volt meter ? if so put red line to outlet sides(1 at a time) and Black to ground. whats your voltage ? both should be 120ish....

But I suspect other motives for the post.....

 

[Ferrino]

Not sure why the compressor link doesn't work - anyway, you can find it by Googling: "Kobalt 3.7-HP 60-Gallon 155-PSI Electric Air Compressor".

What is the brand of the electrical panel u have?

Sorry, not sure how to find the brand - looked but didn't seen anything obvious. Here is a pic, though. The tandem 220v breaker in question is the one with green and blue switches - green is the 30-amp drier circuit I am having problems with and blue is the unused 50-amp range circuit which I would like to re-purpose for my air compressor.

Assuming the breaker is faulty, would it be best to just trash the tandem and replace with independent 30-amp (drier) and 20-amp (compressor) breakers?

OP do you own a Volt meter ? if so put red line to outlet sides(1 at a time) and Black to ground. whats your voltage ? both should be 120ish....

Yeah, that was the whole point of this thread - I measured the voltage at the drier outlet and only saw 110v on one of the hot legs, hence why the drier was spinning but not heating.

Thanks!

 

[AP514]

Not sure why the compressor link doesn't work - anyway, you can find it by Googling: "Kobalt 3.7-HP 60-Gallon 155-PSI Electric Air Compressor".

Yeah, that was the whole point of this thread - I measured the voltage at the drier outlet and only saw 110v on one of the hot legs, hence why the drier was spinning but not heating.

Thanks!

No, what I was saying is check at the C/B to the Ground in the C/B box.....that will tell you if one of the legs from the C/B is bad...if you got power out of each you got a Wire problem

 

[Ferrino]

OK, understood now, I was confused when you said "outlet". Will report back...

 

[Mustang51js]

Looks like more of the breakers are Bryant, but you also have one cutler hammer and two sq-d homeline in there to. You will prob have to put in a seimans or Murray tandom to fit in there, or find a old Bryant tandom online,don't think they make replacements for that panel anymore

 

[Ferrino]

I tested the breaker (Crouse-Hinds) as suggested and indeed one of the legs reports 0v and the other 110v, so will just need to replace this tandem breaker. I'm still unclear which amperage breaker I need for the air compressor as the manual suggests 30-amp, but the current rating is 15-amp, which I think a 20-amp breaker is more suitable for?

Another question: if I disconnect the fat wires from the 50-amp circuit that I no longer need (for the old electric range), what is the appropriate way to terminate those wires in the panel? Would I just put some wire nuts on them?

 

[LS6 Tommy]

If the compressor manual states 30A protection, that's the size breaker you need. I may be wrong, but I'm pretty sure you can just cap the unused 50A circuit wires in the panel. Make sure you label them.

TOmmy

 

[pattenp]

I believe this is what you need....
http://www.amazon.com/gp/product/B000SKY58A/?tag=atomicindus08-20

also should work....
http://www.amazon.com/dp/B004YK5PW0/?tag=atomicindus08-20



*

 

[Norcal]

The Panel is a Crouse-Hinds, which is now Murray again.

 

[AP514]

Great to hear you found the trouble....and a listing for the new C/B...


Now Start another Thread when your ready and we will talk about your wiring for that Compressor (for a 30A C/B your going to need to run 10 gauge wire)

 

[wyliesdiesels]

I tested the breaker (Crouse-Hinds) as suggested and indeed one of the legs reports 0v and the other 110v, so will just need to replace this tandem breaker. I'm still unclear which amperage breaker I need for the air compressor as the manual suggests 30-amp, but the current rating is 15-amp, which I think a 20-amp breaker is more suitable for?

Another question: if I disconnect the fat wires from the 50-amp circuit that I no longer need (for the old electric range), what is the appropriate way to terminate those wires in the panel? Would I just put some wire nuts on them?

I think u said the compressor is 3HP. Wire is sized at 125% of table FLC wich is 17a. So your wire needs to be #12 THHN or #10 NM-B. Circuit breaker can be a max of ~42a but u can go lower.

Great to hear you found the trouble....and a listing for the new C/B...


Now Start another Thread when your ready and we will talk about your wiring for that Compressor (for a 30A C/B your going to need to run 10 gauge wire)

for a regular circuit thats usually the case but circuit breakers for motor circuits are NOT sized to protect the wire. Protrcting the wire and motor is the job of the overload!

 

[Ferrino]

Thanks again! So, in summary, I am going to replace the faulty 50-30 tandem 220v breaker with a 30-30. I will remove the unused 50-amp wires and cap them with wire nuts and label them. I will then wire the new 30-amp circuit (for my compressor) with #10 NM-B wire and hook it up to a 30-amp 220v outlet in the drywall (NEMA6-30). Does this sound right?

Out of interest, why do you think they suggest a 30-amp breaker for a motor rated at 15 amps? Is such an overhead typical for a motor like this?

 

[wyliesdiesels]

Thanks again! So, in summary, I am going to replace the faulty 50-30 tandem 220v breaker with a 30-30. I will remove the unused 50-amp wires and cap them with wire nuts and label them. I will then wire the new 30-amp circuit (for my compressor) with #10 NM-B wire and hook it up to a 30-amp 220v outlet in the drywall (NEMA6-30). Does this sound right?

Out of interest, why do you think they suggest a 30-amp breaker for a motor rated at 15 amps? Is such an overhead typical for a motor like this?

Yup sounds good. U only need #10-2 NM-b aka Romex but ucould get 10-3 in case u ever plan to repurpose the circuit for something that needs a neutral!

The reason the breaker is that high is because of in-rush currents which can be 4x-6x FLC! Just remember that the reaker doesnt protect the wire in the case of motors. Thats the job of the overloads which is either found in the motor starter or probably in your case inside the motor. You would see a red button on the end of the motor!

 

[Ferrino]

Thanks. If I was to use 10-2 cable, I would obviously be passing a white and a black wire to the breaker. Do I need to mark the white cable in some way to indicate it is now "hot" and not "neutral"?

 

[Mustang51js]

Thanks. If I was to use 10-2 cable, I would obviously be passing a white and a black wire to the breaker. Do I need to mark the white cable in some way to indicate it is now "hot" and not "neutral"?

Need to color white either black or red with a marker, you could tape it but it's illegal. Since your not getting an inspection I would tape it neatly

 

[Norcal]

Need to color white either black or red with a marker, you could tape it but it's illegal. Since your not getting an inspection I would tape it neatly

Have a NEC code section where it's prohibited to use tape? For smaller wire sizes I prefer a Sharpie just because it's quick but would lose no sleep over some tape if that was all that was on hand, just don't like it as even 1/2" wide phase tape is a pain on 10 & 12 AWG.

 

[Mustang51js]

Somewhere in there it says anything smaller than #6 you can't tape it, I think 2014 it changed to #8 or they got rid of it.