# Service Upgrade Advice



## djn602 (Aug 12, 2009)

I work at a winery in the Mid-West and help with some lower level electrical. We are looking at our next phase of improvements and additions and the time has come to re-vamp our electrical for capacity and to solve some issues. Our two main building are fed by no less than 12 service entrances! We have 240Delta and 480Y services. I believe 240Delta is on the way out plus we really struggle in many panels not having enough spaces for 120volt circuits. Why not go to Wye? Most nameeplates list 208-230 volt 3 ph as acceptable however some only show 230volt. What are the draw backs? I would think we would move to a single large service for the facility being fed from a pad mount transformer. I would guess it would be a 480 (not sure if it would be delta or wye) then that would feed our switchgear and then another transformer to go to 208Y or 240Delta...

I did read in another post the following:
"One problem with a delta system is if the two 120 volt legs are loaded to the gills and the high leg (phase B in this case) has little load on it, there'll be a voltage imbalance between the 3 line-to-line voltages. On a 240 volt system, anything more than about 6 volts of imbalance will wreak havoc with 3 phase motors."

To date we have probably spent $10-15k on replacement motors, PLCs and other items that inexplicable die!

Also we are pondering back-up generator(s) to keep us functioning in outages.

We have an engineering firm working up a proposal but I would like to be able to have at least a somewhat intelligent conversation with them as we make the choices in the upgrade so I have come here to learn and see what you all think.

I have attached some pictures for your viewing pleasure.

TIA!


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## bobelectric (Feb 24, 2007)

Where does your electric ownership begin?


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## MDShunk (Jan 7, 2007)

DJN, do you buy primary or is this utility owned distribution? You have a pretty messed up system, from the looks of it, and I highly recommend that you guys bite the bullet and pay an EE a couple grand (probably not much more than 2K) to evaluate what you have and recommend a master plan. From what I read and see, you've sorely outgrown your hodge-podge system that you have.

Between me and you, what you should be buying is 480 WYE, and do your own 240 (or 208) distribution in house, as necessary.


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## Magnettica (Jan 23, 2007)

$38,000


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## user4818 (Jan 15, 2009)

Magnettica said:


> $38,000


I came up with $1/ sq ft.


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## djn602 (Aug 12, 2009)

bobelectric- The POCO provided the cans and feeds to the weatherheads.

MDShunk- I foresee us having a nice utility area with switchgear and distro transformers and then re-feeding to all the panels that are now fed by the weatherheads.

Trust me, we are investing in the services of an engineer. I just want a better understanding overall becasue I like electrical. I also want an understanding of what to expect and why go route a over b and such as I think it will lend itself to a better outcome.

So if you feel like teaching , How come 480 wye? What dictates 240Delta over Wye use and vice versa? What are the UPs and DOWNs?

Peter D and Magnettica- What is the $38,000 figure for?

Thank you all very much for your time.


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## RePhase277 (Feb 5, 2008)

A wye service offers a neutral point that is easily groundable, whereas a delta does not. With a delta service, you either need to ground a midpoint between two phases, creating a 120/240 V system with a high leg, or you pick a phase and ground it, called a "corner grounded" system, or you install ground detectors or zig zag transformers.

In my opinion, a corner grounded system offers greater voltage stabilty than a wye system, and also cuts cost because single phase equipment can be used to distribute 3-phase power. But I doubt any POCO will install a new corner grounded system.

With a 277/480 V wye, you get a neutral point to ground, you get 277 for lighting, 480 for processes, and from there you can create whatever voltage you need with local transformers.


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