220 off a single pull 20amp

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Last week I picked up a new power washer the takes a nema 5-20r, no big deal my panel is old but has space so it hook up a quick outlet box on a breaker and put it in one of the many open spots. After I finish I test it and it show 220 at the outlet, baffled I decided to move the breaker down to the next open spot on the same side and it test again at 220. After this I figure maybe these two spots where a issue to the previous owner because they had skipped over the (now empty) spots and recovered with those plastic fillers. So I then put the breaker in a open spot on the otherwise and it test 110 and works perfectly, happy it works but now im confused.... Maybe time for a new panel?

 

[Musicinabottle]

Single pole?

 

[Need more space]

Single pole?

Yes, sorry single pole 20amp General Electric breaker

 

[Norcal]

220 volts is a line and a neutral but not used in the US, what brand of panel is it? Sounds almost like a GE panel, & a twin breaker not being plugged to the correct bus stabs, photos are very helpful.


Is this panel in your house or in a shop? Almost sounds like a 120/240 3 phase panel where the breaker was plugged into the high leg which is 208V line to neutral.

 

[bigb56]

Is this panel in your house or in a shop? Almost sounds like a 120/240 3 phase panel where the breaker was plugged into the high leg which is 208V line to neutral.

That was my first thought

 

[Need more space]

220 volts is a line and a neutral but not used in the US, what brand of panel is it? Sounds almost like a GE panel, & a twin breaker not being plugged to the correct bus stabs, photos are very helpful.


Is this panel in your house or in a shop? Almost sounds like a 120/240 3 phase panel where the breaker was plugged into the high leg which is 208V line to neutral.

Yes it's a GE, it's a panel in my shop. It's not a twin breaker but I guess I could have put it in the wrong spot. I tried two spot on the right side, one high and one below other 110 circuits and got 220. Move it to the left side higher up and had no problems.

 

[Matt Matt]

Did you actually conduct a test between your two hots? What does your voltage metre read? What is each hot to ground voltage reading??? What is hot to hot voltage reading???

 

[wyliesdiesels]

Yes it's a GE, it's a panel in my shop. It's not a twin breaker but I guess I could have put it in the wrong spot. I tried two spot on the right side, one high and one below other 110 circuits and got 220. Move it to the left side higher up and had no problems.

Can you post a pic of the panel with the cover off?

The only way you would get higher than 120v with a single pole breaker is if you have a 240v delta service which Norcal pointed out above.

And are you sure its 220v? Hi leg to neutral is 208v and 220v is not available in the US.

Once again we see why its important to list the correct voltage instead of interchanging 220 for 240v or 208v. Naysayers take note.

 

[Need more space]

Did you actually conduct a test between your two hots? What does your voltage metre read? What is each hot to ground voltage reading??? What is hot to hot voltage reading???

I first tested at the outlet hot to neutral and got in the 238, then test hot to ground and got the same. I then took panel cover off and tested from the screw terminal on breaker to neutral bar and got the same high results in the two spots. After I moved it to the other side and tested from breaker to neutral I had 110 and it worked just fine.

 

[Need more space]

Can you post a pic of the panel with the cover off?

The only way you would get higher than 120v with a single pole breaker is if you have a 240v delta service which Norcal pointed out above.

And are you sure its 220v? Hi leg to neutral is 208v and 220v is not available in the US.

Once again we see why its important to list the proper voltage instead of interchanging 240 with 220v. Naysayers take note.

Ill get some photos today!

 

[Matt Matt]

I first tested at the outlet hot to neutral and got in the 238, then test hot to ground and got the same. I then took panel cover off and tested from the screw terminal on breaker to neutral bar and got the same high results in the two spots. After I moved it to the other side and tested from breaker to neutral I had 110 and it worked just fine.

OK, you got me a little bit confused. Is this in residential?

For example; at this present minute
-I’m reading 243 V, red hot to black hot, on my residential.
-I’m reading 120.7 V, red hot to white neutral.
-I’m reading 120.7 V, red hot to green/ground.
-I’m reading 121.3 V, black hot to white neutral.
-I’m Reading 121.3 V, black hot to green/ground.
-And for fun, I am getting 0.015 V white neutral to green/ground.

 

[teamextreme]

I first tested at the outlet hot to neutral and got in the 238, then test hot to ground and got the same. I then took panel cover off and tested from the screw terminal on breaker to neutral bar and got the same high results in the two spots. After I moved it to the other side and tested from breaker to neutral I had 110 and it worked just fine.

That makes no sense and I can't think of any way that's possible in a residential setting. You need to answer the question as to where this is, residential or commercial? The only explanation is as mentioned above a hi leg delta setup, which is not residential. Although that would not give you the 238V you measured. This is REALLY strange.

 

[nsula_country]

Some older neighborhoods have 3 phase... So I have heard.

CT

 

[Norcal]

Some older neighborhoods have 3 phase... So I have heard.

CT

Common in Arizona, used a Delta Breaker for the A/C & the panel was 1Ø. That setup is no longer code compliant.

 

[bigb56]

Common in Arizona, used a Delta Breaker for the A/C & the panel was 1Ø. That setup is no longer code compliant.

I never knew you were in Arizona, I always thought you were in, well, Nor Cal.
We've changed out a number of residential 3 phase services to single phase. Back when AC was in it's infancy a lot of them were 3 phase, and AC was a big deal in desert towns.

 

[Need more space]

OK, you got me a little bit confused. Is this in residential?

For example; at this present minute
-I’m reading 243 V, red hot to black hot, on my residential.
-I’m reading 120.7 V, red hot to white neutral.
-I’m reading 120.7 V, red hot to green/ground.
-I’m reading 121.3 V, black hot to white neutral.
-I’m Reading 121.3 V, black hot to green/ground.
-And for fun, I am getting 0.015 V white neutral to green/ground.

Sorry, when above post asked shop or home I said shop. Sorry wasn't clear my shop is a older commercial building. Today I took pictures and retested and I kept getting approximately 217 to 220 ish readings not in the 230s. I'm going to post some pictures. -Thanks everyone!

 

[wyliesdiesels]

The only thing OP has said is that this is in a shop.

So is this shop commercial or on a residential property?

The voltages readings dont make sense.

There is no way one can get 110v and 238v on any kind of system.

Once again the 110v/220v name lovers should take note of this thread and see why using the correct values are important especially when diagnosing over the internet.

 

[Need more space]

Sorry guys retested today and got a consistent 217-220 reading, don't know how I seen 238 yesterday. Maybe I was a bit stressed

 

[wyliesdiesels]

Sorry, when above post asked shop or home I said shop. Sorry wasn't clear my shop is a older commercial building. Today I took pictures and retested and I kept getting approximately 217 to 220 ish readings not in the 230s. I'm going to post some pictures. -Thanks everyone!

Sounds like you have a hi-leg delta service thats a little on the high side.

The nominal voltage on a high leg is 208v to neutral/ground. Yours is a little hot.

But this is why one needs to have some experience when working on commercial electrical services.

Lots of 120v equipment has been burned up due to inexperinced people hooking up 120v outlets to hi-legs.

 

[Need more space]

Sounds like you have a hi-leg delta service thats a little on the high side.

The nominal voltage on a high leg is 208v to neutral/ground. Yours is a little hot.

But this is why one needs to have some experience when working on commercial electrical services.

Lots of 120v equipment has been burned up due to inexperinced people hooking up 120v outlets to hi-legs.

I agree, almost plugged my new powe washer into it. Very happy I tested it first!

 

[wyliesdiesels]

I agree, almost plugged my new powe washer into it. Very happy I tested it first!

Post the readings from each phase and neutral.

Your hi-leg is about 6% over nominal.

Depending on the readings you get on the other legs, you may want to call the PoCo.

 

[Bert_]

Sounds like you already have an idea what's going on, but here's a couple things to look for anyway,

Do you have four wires feeding your panel, three going into the main breaker?
Is one of the wires marked red or orange?
Is there a lot of empty spaces every third slot in the panel.

A 240v delta is / was a very common light industrial / commercial service.

Lot of people get scared by this setup because it can be a little confusing, but it makes sense once you understand it. A delta is actually better than a wye if you have a lot of motors or 3 phase machinery.



A, B, C and neutral are the four wires feeding your panel.

A, C and neutral act just like a normal single phase service. The third leg (high leg) can only be used for 240v loads.

 

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when you look at post 24 you can see on the right side you have two beakers, then a open spot, then two more breakers, then a open spot. Those are the two spots I first installed the breaker and got the over 200 reading. After that I moved the breaker to the left side (second from bottom) and everything tested good for a 110 outlet.

Also notice no grounds in box, neutral bar is grounded so I had planned on running grounds if I don't end up hiring someone to install a new panel if thats needed.

 

[GRB]

Clearly 240 3 phase delta. You can’t put any single pole breaker in any third slot. You would get 208v and the breaker would need to be rated for 208v. Until you completely understand this system, don’t do anything.

 

[TRWham]

Yes, that is a 3 phase panel apparently served by a delta wired transformer through a back-feeding circuit breaker. Every third position will be plugging into the high leg. You can get 240V single phase across any 2 legs but line to neutral will only be correct between 2 of the 3 and neutral.

 

[Bert_]

Definitely a delta. Your high leg is on the C phase which was not uncommon in older panels. Keep single pole breakers away from every third slot, two pole breakers can use the high leg as long as it doesn't use a neutral. Anything 3 phase would obviously use all three legs. In my earlier post I drew a diagram explaining why there are different voltages, just switch B and C in my diagram.

Panel is fine other then the open knock outs and a couple off brand breakers. If those circuits are in metal conduit then the conduit can be a ground.


*apparently I type slow

 

[bigb56]

Don't take this too personal but if you didn't realize that was a 3 phase panel the moment you opened the door you are obviously in over your head and should not be doing your own electrical work without someone experienced by your side. Bad things can happen. Just sayin

 

[Matt Matt]

You have a three-phase system. It should be 120/208/120

The main breaker is the top left and they’re all tied together. There is three different hit’s coming in.

L2 should be your 208 to neutral. But just in case it’s not...

Test:
L1 to L2=
L1 to neutral=
L2 to L3=
L2 to neutral=
L3 to L1=
L3 to neutral=

And let us know what your numbers are.

 

[Need more space]

Don't take this too personal but if you didn't realize that was a 3 phase panel the moment you opened the door you are obviously in over your head and should not be doing your own electrical work without someone experienced by your side. Bad things can happen. Just sayin

I agree 100%, however I had new neighbor who said hes a union electrician tell me I was completely wrong and didn't have 3 phase. I had told him I thought I did, he assured me I didn't...

 

[TRWham]

Looks like L3 is the high leg based on the empty positions and possibly a little yellow tag on the main breaker.

 

[Need more space]

You have a three-phase system. It should be 120/208/120

The main breaker is the top left and they’re all tied together. There is three different hit’s coming in.

L2 should be your 208 to neutral. But just in case it’s not...

Test:
L1 to L2=
L1 to neutral=
L2 to L3=
L2 to neutral=
L3 to L1=
L3 to neutral=

And let us know what your numbers are.

Ill get those numbers tomorrow, thanks a lot for the help!!!!

 

[Copymutt]

Had that set up in my commercial shop. One day started getting 58 volts on one side of the panel for those circuits and something like 180 on the other leg.
Went outside and watched the conduit where it entered the box doing a hell of a arc welding dance. Ice damage and conduit separation started it.
Jim

 

[Matt Matt]

Looks like L3 is the high leg based on the empty positions and possibly a little yellow tag on the main breaker.

I agree, but it is usually put in the middle.

 

[ssdave]

For safety sake, (future users) use a sharpie and mark in the open area over the top of the breakers "3 PHASE, 240V Delta"

On the top breaker (3 coupled together) Clearly mark "MAIN".

I dislike backfed mains, too easy for someone that doesn't understand them to fry themselves. Even someone who understands them can make a mistake if they're not labeled clearly. I had that happen on a job to a very good electrician that had done a lot of work for me over a period of years. We were disconnecting a UPS system, that had a subpanel that had been wired badly, probably by the computer techs. It was unlabeled. I don't recall the exact circumstances, but it went something like this: It looked like the backfed main was the feed to the UPS, as there was a main breaker also. We shut off the main panel breaker that was labeled to feed the UPS subpanel, shut off the main breaker in the subpanel, and then broke the UPS in the middle of the battery array, and then disconnected battery by battery. Standard procedure for safely breaking down a battery array. Then, took off the panel cover, and used a non-contact tester to determine that the wires feeding the main disconnect were dead. We didn't think to test the breaker leads, as we knew the UPS was disconnected. My guy put a screwdriver to the breaker terminal, and removed one wire. It swung loose and hit a bus bar and the panel blew up in a ball of fire.

What had been done is they backfed the breaker from a panel, and backfed the UPS through the main. So, if they shut off the main, the UPS was isolated, but the panel was still live and the circuits on the UPS would be live also. I don't know how they had fed the backfed breaker, but must have been through some kind of transfer switch, and it wasn't through the labeled breaker that we had disconnected. We were salvaging the UPS and battery array, so didn't investigate further. Just cleaned out our pants and finished the job!

The guy I had doing the work was very good, and had probably about 25 years of solid commercial experience. What it really taught me, was to check all wires with a non-contact tester. He said the same thing, he just got sloppy that day and relied on having disconnected the things he presumed were the hot feeds into the panel.

I personally label backfed mains with that wording "BACKFED MAIN".

 

[GRB]

The Union Electrician Neighbor is incompetent on this system. The "High leg" is clearly Phase C on this system which was the norm on earlier systems. They switched to Phase B in the late 1970s or 1980s depending on the area.
The "Hot Leg" aka "High Leg" feed should be marked with red tape where it comes in but the obvious give away is the every-third-breaker-slot blanking plate starting with #3.
Since there isn't an actual transformer pot on the hot leg, you should NOT use it for any single pole breakers even if you could get a single pole breaker rated for 208v, which is unlikely. That means a breaker that says 208v or more, NOT 120/240v. The POCO tell you in general to NOT use it anyway.
A 3 phase breaker goes across all three obviously. A normal 2 pole 240v can go across any two as long as you don't use the neutral for that load since one side is 120v and the other is 208v. Single pole 120v can go anywhere except in the third slot and every third after that such as #3, #6, #9, etc.

 

[Matt Matt]

For clarification A,B,C=>L1,L2,L3=>U,V,W in other countries.
Neutral=>is a shielded ground “zero” line, also known as white.
Ground=> is Bare or shielded green or yellow with green stripe.

I usually need to deal with A whole array of motors from single phase to three phase from 120-575v. RPCs, VFD‘s, SFC and capacitor banks... but the blue wire should now jump in at higher volts.

I personally look forward to seeing the tested results.

I personally have RPC’s that generate pretty much close to the same voltages, (At Idle). These are delta system generators with high/wild leg.

 

[Need more space]

After reading all this information I'm sure glad I tested that outlet and realized something I was messing with was more then I knew. The more I think about it I almost want to hire someone to put in a new single phase panel.