Neutral to wild leg

[AlphonseDoll]

I HAVE A 240 VOLT DELTA SERVICE WHICH IS ACTUALLY 248 VOLTS BETWEEN LEGS AND A CENTER TAP NEUTRAL ON ONE PHASE TO GIVE ME 120/240. THE WILD LEG IS ACTUALLY 218 VOLTS TO THE NEUTRAL. IS THE USE OF THE NEUTRAL AND THE WILD LEG A LEGITIMATE, LEGAL AND IN CONFORMITY TO NEC.

 

[tortuga]

I HAVE A 240 VOLT DELTA SERVICE WHICH IS ACTUALLY 248 VOLTS BETWEEN LEGS AND A CENTER TAP NEUTRAL ON ONE PHASE TO GIVE ME 120/240. THE WILD LEG IS ACTUALLY 218 VOLTS TO THE NEUTRAL. IS THE USE OF THE NEUTRAL AND THE WILD LEG A LEGITIMATE, LEGAL AND IN CONFORMITY TO NEC.

I have never seen it on a two wire grounded circuit what would be the use case for that?
You would need 240V 'straight' rated single pole breakers or fuses and orange wire..
Voltage will be pretty unstable.
No code section against it that I know of...

 

[electrofelon]

I have never seen it on a two wire grounded circuit what would be the use case for that?
You would need 240V 'straight' rated single pole breakers or fuses and orange wire..
Voltage will be pretty unstable.
No code section against it that I know of...

Also, in my experience, many/most utilities will tell you not to do that.

 

[tortuga]

Now that I look 220.5 calculations does not have a plain 208V nominal system. Which is what this would be. So you cant do a load calc for the circuit. Also 210.6(C) limits the use.
And actually I do recall seeing such many such a circuit functioning a long time ago although I thought it unintentional at the time and 'fixed it'. It was a multi-wire branch circuit feeding L-N fluorescent lighting 208V to gnd on one leg 120 on the other.. 100-277 electronic T8 ballasts. Two pole breakers in a 3 phase panel.
However I imagine to keep such a circuit you would need a 10 AWG neutral sized similarly to old two phase as the phases don't balance...

 

[mivey]

You would need 240V 'straight' rated single pole breakers

Which is the tough part.

Voltage will be pretty unstable.

The voltage will be stable.

 

[mivey]

Also, in my experience, many/most utilities will tell you not to do that.

As long as you don't overload the transformer, they shouldn't have a problem with it.

 

[infinity]

I HAVE A 240 VOLT DELTA SERVICE WHICH IS ACTUALLY 248 VOLTS BETWEEN LEGS AND A CENTER TAP NEUTRAL ON ONE PHASE TO GIVE ME 120/240. THE WILD LEG IS ACTUALLY 218 VOLTS TO THE NEUTRAL. IS THE USE OF THE NEUTRAL AND THE WILD LEG A LEGITIMATE, LEGAL AND IN CONFORMITY TO NEC.

I would consider the 208 volt circuit unusual for the reasons already mentioned.

Welcome to the Forum and please turn off your Caps Lock.

 

[Jraef]

Use it for what though? The load device would need to be rated for 208V single phase. Do you really have something you need to connect that has that rating? If so, then you should also check with the mfr that it will be OK with 208V L to N instead of 208V L to L, and if it OK with 218V. Most equipment rated for use on 208V only is actually rated for 200V, so 218V might be at the far end of acceptable. It’s sll probably OK if you have that 208V device, but what you are wanting to do is not normal, so you should take responsibility for making sure as opposed to ASSuming.

 

[jaggedben]

Use it for what though? The load device would need to be rated for 208V single phase. Do you really have something you need to connect that has that rating? If so, then you should also check with the mfr that it will be OK with 208V L to N instead of 208V L to L, and if it OK with 218V. Most equipment rated for use on 208V only is actually rated for 200V, so 218V might be at the far end of acceptable. It’s sll probably OK if you have that 208V device, but what you are wanting to do is not normal, so you should take responsibility for making sure as opposed to ASSuming.

Lot's of 240 devices would work okay at 208. Heaters, for example. But yeah,

 

[Andy Delle]

The voltage will be stable.

Well that depends. is this fed from an open delta or closed delta transformer bank?

 

[AlphonseDoll]

Electrical contractor

Electrical contractor

I have never seen it on a two wire grounded circuit what would be the use case for that?
You would need 240V 'straight' rated single pole breakers or fuses and orange wire..
Voltage will be pretty unstable.
No code section against it that I know of...

This is a closed delta 240 volt system that the utility decided to put in. Expresso machine has 220 volt rating, one installer said we needed a buck/boost transformer,but going to the'wild leg' and neutral seems to accomplish the thing. We are checking with manufacture to see if warranty would still be intact. For a 1st time poster, I appreciate all the responses. Local inspectors say they never heard of such a hook up, but did not see anything wrong with it. Don't know why utility wanted a delta transformer bank, which was installed new for this bakery.

 

[LarryFine]

This is a closed delta 240 volt system that the utility decided to put in. Expresso machine has 220 volt rating.

For that machine rating, I would use any two phases. I try to place 240 loads on the high leg and either other line, and save the two 120v legs for loads that also require the neutral.

 

[Jraef]

This is a closed delta 240 volt system that the utility decided to put in. Expresso machine has 220 volt rating, one installer said we needed a buck/boost transformer,but going to the'wild leg' and neutral seems to accomplish the thing. We are checking with manufacture to see if warranty would still be intact. For a 1st time poster, I appreciate all the responses. Local inspectors say they never heard of such a hook up, but did not see anything wrong with it. Don't know why utility wanted a delta transformer bank, which was installed new for this bakery.

Is it a "pump" type espresso machine, i.e. it has an AC motor inside? If so, and it's rated 220V 50Hz, you have more than just that problem.

Other than that, don't get excited about what the sales literature says. Most equipment sales dept. people have no clue. For example, this is a site for a "Rancillo" commercial Espresso machine, one I have put in to several shops (I help out a local coffee company).
https://www.seattlecoffeegear.com/rancilio-classe-7-usb-commercial-espresso-machine
The website AND the front page of even the spec sheet both say "220V".

But drill down into the actual installation manual, and it says this:

SERVICE CONNECTION
ELECTRICAL CONNECTION:
Espresso Machine
Voltage Range:
208 - 240 V
Watts:
6000
Circuit Size:
30 Amps
Suggested Receptacle:
NEMA L6-30R

Even if someone calls the guys I help out (who are the importers of the Italian machines), their own "tech support" people will tall them "Yes, it's 220V" because they don't really understand how things work when it comes to electricity. So people on the other end run out and buy buck-boost transformers. But they are a total waste...

 

[mivey]

Well that depends. is this fed from an open delta or closed delta transformer bank?

Voltage will be stable either way. Balance/regulation will not be as good with the open delta but that is not unstable.

Just don't overload the transformers. To keep good balance, 50% loading should work fine and works good for 3-phase loads. I have not run it for a real single-phase high-leg to neutral load but I may have made a calc as a what-if for fun. I don't recall off-hand.

 

[JFletcher]

With the above caveats mentioned, using the high leg or B phase along with the neutral should work fine, however I am not so sure that it is acceptable to wire a Nema 6 series receptacle with one 208 leg and one neutral...