# closed delta 208v high leg



## nolabama (Oct 3, 2007)

You want 2 more 120 legs from the high/wild/stinger leg? I do not think you can do that. What would an unused stinger leg have to do with balancing a load. If you pay extra for the stinger leg and do not need it call your power company and tell them to remove it.


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## nitro71 (Sep 17, 2009)

I'm curious how this will change your power bill? Has the POCO told you that this will lower your power bill? Watts is watts... I'm sure you could get a 240 Delta to 120/208 Y transformer but I'm guessing your power bill isn't going to change unless they are billing you excessively for unbalanced load?


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## RePhase277 (Feb 5, 2008)

Adding a transformer isn't going to lower your bill. In fact, the losses in the new transformer will actually increase it. The only way to lower the bill is to decrease the load.


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## nolabama (Oct 3, 2007)

What I do not understand is that they are polly charging this guy for the wildleg service and if he is not using it why not just cancel it.


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## rlc3854 (Dec 30, 2007)

I'm still trying to understand how any "ELECTRICIAN" thinks they can get two 120v lines from a stinger leg. He may want to look into one of those line conditioners that just smoothes out the electron flow:whistling2:


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## nolabama (Oct 3, 2007)

Or one of those power quality thingamabobs that spin your meter backwards.:thumbsup:


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## electricalperson (Jan 11, 2008)

why not get a 120v/208v wye service instead whats the point in having a 208v stinger leg? all i see is blown up loads


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## micromind (Aug 11, 2007)

If one were to connect a transformer with a 208 primary to the high leg and neutral and it had a secondary of 120/240, this could be connected to a single phase panel. 

It'd work, except for a few small issues. 

1) Neutral current. I've never connected a load from the high leg to the neutral, and I don't know of a delta system to experiment on. I'm not sure what effect this connection would have on the neutral current, but I'd bet it'd add to the other two legs. That'd be bad. 

2) Overcurrent protection of the transformer primary. Single pole breakers used 120/240 panels are typically rated at 120/240. This means the breaker can interrupt line to neutral or ground current at 120 volts. It can also interrupt line to line current at 240 volts only if used in conjunction with another breaker. 

If it were to interrupt a fault level current with 208 across it, it'd very likely explode. You'd need a single pole breaker rated at 208 volts. I've never seen one. Breakers rated at 277 volts certainly exist, but they won't fit in a 120/240 panel. 

As stated above, this will have very little effect on the power bill. The losses in the transformer (small, but they do exist) would actually raise it slightly. 

A good idea, in theory, but not a good idea in practicality.

Rob

P.S if you have any 240 volt loads that don't involve the neutral, you certainly can use the high leg along with one of the other legs, just not the neutral. If so, use a two pole breaker that's rated 240 volts, not 120/240.


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## RePhase277 (Feb 5, 2008)

micromind said:


> 2) Overcurrent protection of the transformer primary. Single pole breakers used 120/240 panels are typically rated at 120/240. This means the breaker can interrupt line to neutral or ground current at 120 volts. *It can also interrupt line to line current at 240 volts only if used in conjunction with another breaker. *


Rob, the bold statement above, what do you mean? I confess I'm no overcurrent protection engineer by any stretch, so I'm a little ignorant. The same fault current flows through each pole of a double pole breaker during a line-to-line short. What changes if the breaker is a single pole interrupting the same current at the same voltage?


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## TheROCSparky (Dec 27, 2009)

*back to the beginning*

Thank you all for your input on my problem to answer a few questions 1. yes i do use the "wild" leg for my elevator, boiler motors, and a few other odd things 2.The POCO wont diconnect the high leg I should mention that this property of mine is in the middle of nowhere coal country PA this is the only type of service i can get without paying for the change over which includes buying the XFMR if needed. 3 I did say that I was "reading up" on XFMR theory I don't know all there is to know about them hence I said "MAYBE" two 120 legs. 4. Yes it would help balance the loads the high leg for lack of better terms is mostly unused the aforementioned short list of items that utilize the high leg dont run constantly or even every day. Again thank you all for helping me out, and now that I've put more into the story maybe I'll get more back


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## nolabama (Oct 3, 2007)

TheROCSparky said:


> 1. yes i do use the "wild" leg for my elevator, boiler motors, and a few other odd things
> 
> 2.The POCO wont diconnect the high leg I should mention that this property of mine is in the middle of nowhere coal country PA this is the only type of service i can get without paying for the change over which includes buying the XFMR if needed.
> 
> ...



Answer Statement 4

How would another service "balance" anything????:no:


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## micromind (Aug 11, 2007)

InPhase, I guess my statement was kind of misleading. What I meant was a single pole breaker can interrupt a 240 volt fault if it is one part of a two or 3 pole common-trip breaker. 

The idea is that the current interruption is shared by the other breaker, thus the duration of the arc is shorter. 

Rob


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## TheROCSparky (Dec 27, 2009)

are you sure you know how a closed 4 wire delta is wired on the output side (taps)of xfmr ONE the two taps each 120v one tap feeds primary side of the second xfmr (xfmr 2) the tap off that xfmr 208v plus a neut = 4 wire closed delta (120, 120, 208, neut) all loads come off of the two 120v legs the poco sees this as a huge draw of currant from all legs when in reality no current is being used from the high leg the 208v IF i were to CHANGE the service I would change it to a wye and have three or maybe four legs of 120v into my building but I WOULD have to pay for the change over (meter can, Meter, bulldogs....) and the pole gear but since seeing that would cost in excess of $60,000 I'll stick with what i have oh did i mention that the township doesnt have a three phase poco connection that would make it even harder the point is i need the three phases for somethings but i'd like to put the high leg, to better use and its not hard math to figure out how that would balance out the loads and lower my bill


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## RePhase277 (Feb 5, 2008)

The POCO is charging you by how much energy is used. Period. It doesn't care if you use the high leg or not. A kWh is a kWh. Even if you change the service or balance the load with another transformer, you are still using the same total amount of energy.

If your power bill is killing you, the only way to lighten it is decrease the load.


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## TheROCSparky (Dec 27, 2009)

yes this kinda true ex pouring water into three straws if you hold the three straws together side by side and pour water through them is 1/3 of the water going throgh each straw answer NO it appears as though it is but the currant is stronger in the middle than at each side maybe E.T. 101 is order


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## rlc3854 (Dec 30, 2007)

TheROCSparky said:


> yes this kinda true ex pouring water into three straws if you hold the three straws together side by side and pour water through them is 1/3 of the water going throgh each straw answer NO it appears as though it is but the currant is stronger in the middle than at each side maybe E.T. 101 is order


WTF, get a copy of the American Electrician's Handbook and review the chapter on transformers, OHM's law and therory:blink:


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## DipsyDoodleDandy (Dec 21, 2009)

*Unity*

Are you trying to achieve unity for a high power factor?


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## RePhase277 (Feb 5, 2008)

TheROCSparky said:


> yes this kinda true ex pouring water into three straws if you hold the three straws together side by side and pour water through them is 1/3 of the water going throgh each straw answer NO it appears as though it is but the currant is stronger in the middle than at each side maybe E.T. 101 is order


:laughing::laughing: If you say so champ! But the fact still remains that the meter is recording the amount of KILOWATT-HOURS used, for all three phases. It does NOT matter if one of the phases is lightly loaded


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## nolabama (Oct 3, 2007)

TheROCSparky said:


> are you sure you know how a closed 4 wire delta is wired on the output side (taps)of xfmr ...............................................
> 
> 
> the point is i need the three phases for somethings but i'd like to put the high leg, to better use and _*its not hard math to figure out how that would balance out the loads and lower my bill*_



_*Show me the math. 

*_Demand is what costs you money. Want to save money - hang an OUT OF ORDER SIGN on that elevator.


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## nolabama (Oct 3, 2007)

rlc3854 said:


> WTF, get a copy of the American Electrician's Handbook and review the chapter on transformers, OHM's law and therory:blink:



What the fellow from Amite said X's 1,000,000


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## DipsyDoodleDandy (Dec 21, 2009)

*Charge*

I think they charge by total power (true power) , demand, and/or a power factor charge? Im not sure how they base that one though. Can anyone chime in on the last? Ex. If your 80% PF they might charge you more then your true power with an additional penalty


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## nolabama (Oct 3, 2007)

Power factor. I have heard of correction factors by the Utilities for this but I have no knowledge of it. I have a feeling that this guy's elevator and boilers are running his light bill up, not a stinger leg.


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## micromind (Aug 11, 2007)

This is very likely a small issue, but a 3 phase motors efficiency will decrease with unbalanced phases. Not much, but it does. 

On your bill, is there a demand charge? How about a KVAR charge? These can usually be reduced to some degree. 

As stated above, if the bill is for KWHRs only, it doesn't matter what leg the usage is from, a KWHR is a KWHR. 

Rob


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## Cardiocase (Dec 21, 2009)

Quick question(s). What's the incoming transformer setup (_3 seperates, or two with an open delta, or a large self contained poly_..??) on the pole (pad),, and you said something about adding a transformer.?? I'm assuming a "dry" type singlephase..??


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## piperunner (Aug 22, 2009)

New to this forum but hope to help out read the post a closed delta trans has a larger C winding attached to A phase winding and B phase winding each phase ABC is electrical 120 out of phase angle with the other in rotation .

B phase HI LEG is 90 deg out from all other phases its a balance issue here it is not normal to use it .

But lets just say you use B hi leg for you project .


The current flow runs to center tap common point on center C winding which shares the 120 volt loads of B/A now aready on C winding center tapped but its at a different voltage and also out of place with A/B the current down B leg splits 1/2 cycle into say center C towards A and next 1/2 cycle towards B via C winding to get any balance would be a fine line not a easy task .

A/B TO C are not in phase with HI LEG B side key point .

I would not use it but lets look a Microminds post nice post you can get a breaker rated 240 volts but there mostly slash rated per nec you can not use a slash /rated breaker on a hi leg the 120 /240 volt rating is lowest voltage is line to ground highest voltage is line to line .


But unbalance will prove its not a effective plan to load up B phase .


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## SpliceMan (Feb 3, 2010)

TheROCSparky said:


> I 'm looking to install a transformer in my commercial space the service is a 4 wire delta with a 208v high leg what i would like to do is set up a XFMR to get two more 120v legs out, maybe from the 208v leg yes i do have panels isolated from the service to accommodate the XFMR. My reason for doing this is to balance the loads every thing now runs on the two 120v legs and the high leg is not used at all I'm reading up on XTMR theory but a need a nudge in the right direction and a quick answer the utility bill is killing me


you can do it but your going to scew up the harmonics of the xfmr and create a dangerous ground loop you'll notice that motors and ballast will burn out incredably fast....that nuetrals only there for the existing service stretch it any farther and it going to draw,plus if its a ground fault service any fault will shut the main off in biulding...DO IT CORRECTLY YOU'LL SAVE A LIFE!!!!!!!if you want to save money make sure your MUA,Heat pumps,AC units and all motors plus equip are all 3PHase 208v


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