transformer efficiencies and private line 1

[maxPE]

Im planning on putting in a private electic line to my farm and retain ownership of the line. It appears that one possible way edison will connect is to meter at the beginning of my line at 480 VAC. The distance from there to my pumps is 1.2 miles so I was planning on xforming up to 4800V for the run then back down to 240V at the pumps. Im concerned that I will be killed on power costs by the two transformers after the meter(up and back down). I would assume that the losses are low but dont have a handle on it. The pump load is 35kw and would be turned off for the high tariff afternnon times. Max PE Mechanical

 

[dpc]

Transformers are incredibly efficient. Your losses might be in the 1% to 3% range. The most important value for your application is probably the core (iron) losses, since these are independent of load and are there 24/7.

If you evaluated your entire system, from service through the pump losses, the transformers would be the most efficient step in the process.

You might check the Cooper Power or Pauwels website to see if you can find efficiency data from small pad-mount transformers.

 

[Shortstub]

Responding to MaxPE's query:

Are you asking for typical efficiency data for:

a) A transformer sized for the load you anticipate? Or,

b) Do you want to calculate best efficiency given core & coil losses?

 

[DanDel]

Ask the utility about primary metering and get a service at the voltage you need for transmission(4.8kV, or whatever they use in your area). This is typically much cheaper than low voltage metering, and since you are planning on owning two transformers anyway, this will save you (and the utility) the cost of one transformer each, and seems to me to be the way to go.
As previously posted, there are practically no transformer losses for you to be concerned about.

 

[maxPE]

Thanks all. I needed an idea of losses. Edison seems to be unhappy about connecting to a 'private line' so I wanted an idea as to options. dealing with a 'franchise' seems to be a pain! Thanks again.
Max

 

[cuky2000]

Trasformer efficiency are in general higher for larger unit the following range are available in the market:
Single Phase: 15 to 333 kVA-->
or Efficiency 97.7 to 98.9
Three Phase: 15 to 1000 kVA-->

Please refer the enclose site for further reference:

http://www.energyusernews.com/CDA/Article_Information/Fundamentals_Item/0,2637,76086,00.html