Feeder Voltage Drop Question

[ipjd2000]

I have been arguing with the local electric company regarding the location of a new power pole and transformer. This transformer will service two new homes (each home with a 200 Amp panel).

The electric company claims that the pole and transformer should be (at most) about 100 feet from the main panels (and meters) because otherwise the voltage drop will exceed 5%. However, positioning the transformer so close to the houses will be expensive and unsightly. I would prefer the pole and transformer to be at a different location about 240 feet away from the main power panels. They have agreed to this farther location with the meters positioned at the base of the pole. (Their responsibility would end at the meter). Based on my calculations, I can then use 250 MCM wire from each meter to feed each panel and still be within a maximum 5% voltage drop.

My question is whether (based on experience) 240 feet is a reasonable distance from the transformer? (My calculations tell me that the voltage drop would be acceptable).

Why would the local electric company be so resistant to having the transformer be this distance from the panel?

Thanks.

Julio.

 

[ron]

They will accept the longer run with their meters at the pole, so the customer pays for the 240V line losses. It will also make it easier for their meter readers.

 

[LarryFine]

Why would the local electric company be so resistant to having the transformer be this distance from the panel?

(Change your question to "Why would the local electric company be so resistant to having the transformer be this distance from the meter?)

Because they would have to foot the bill for the line side of the meter underground run your way?

 

[adrian33773]

I agree with Larry, the power company is just trying to cut their costs.

 

[bsh]

The 250 will give you about 2.6% drop. I always try to keep my feeders at 2% and branch circuits are 3% for a total of 5%.
I'm sure the power company appreciates you paying for the cable from their meter to the house.

 

[ramdiesel3500]

The bigger question, IMHO, is "What is the available voltage at the transformer?" I have an underground feed from the pole to my house that is about 400 feet (200A 1p3w service, 4/0 Al URD feeder cable). However, the voltage at the pole consistently reads between 248V and 252V. So, I can get by with a considerable bit more voltage drop without any problem. I was worried about this when it was originally installed (I had no choice in the matter - long story) but after 11 years of service, the voltage has not changed. The transformer on the pole is a 15KW and I accidentally loaded it to about 230 amps one day (wife was running dryer, washer, cleaning oven, water heater, while electric furnace coils were pulling 30kw(temp -10F outside), all lights in house on, tv on, Service panel buzzing loudly!!!) Voltage was still better than 220V. (I shut down part of electric furnace after taking the voltage reading so as not to explode the transformer - just glad the cold air was able to cool it enough). The 5% voltage drop guideline is a good one, but not an absolute requirement. The Local REMC here suggests not to exceed 300ft from panel to pole for a 200A service with 4/0 URD aluminum conductors.

 

[infinity]

The 250 will give you about 2.6% drop. I always try to keep my feeders at 2% and branch circuits are 3% for a total of 5%.
I'm sure the power company appreciates you paying for the cable from their meter to the house.

How did you figure that without knowing the computed load?