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Greetings DTY electrical gang. When the septic line (running from tank at house to leach field) was installed at our home, running 1400', we included electrical and water lines in the same trench, with the idea that we may develop that part of our property. That time has come.

My questions involve need for transformers. Assuming I begin with 120V at the panel, the voltage drop for 1400' with three 4AWG conductors, using 15 Amps is around 11 volts, according to the AWG calculator I used. do I need a transformer on each end? Will 109 volts adequately run the items in my trailer as long as I don't exceed the 15 amps? Without a transformer, will the power drop be different?

I was recommended to get 600V transformers on each end, and they are pricey, so I'd like to not use them. Any information about this would be appreciated.
 

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Have you priced this wire?
You will need 3 of them to make that run, and what kind of trailer are you talking about to only use 120v @15 amps?
 

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I was recommended to get 600V transformers on each end, and they are pricey, so I'd like to not use them. Any information about this would be appreciated.
No matter WHAT you do at this distance it is going to be VERY "pricey".
1400' is an incredibly far distance for 120/240v, almost regardless of the load.
 
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Have you priced this wire?
You will need 3 of them to make that run, and what kind of trailer are you talking about to only use 120v @15 amps?

A travel trailer, and the only power draw will be lights, computer, radio, TV, coffee maker. Fridge is propane as is stove and water heater. The occasional A/C and washing machine use can be powered by generator.

do I need those transformers at each end to make this work? thanks
 

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1400 feet ??:eek:

That is very serious run there and you will run into serious voltage drop when you load up full 15 amp no question asked.

Are you in USA or Canada ? due there is few differnt rules to deal with it.

Merci,
Marc
 

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If you run 240 volts down the line, then you need one step down transformer, at the far end, to obtain 120 volts.

At 240 volts you can afford to lose 10 volts along the way (4% which is pushing it a tad). That allows 13 amps of 240 volt power, which gives you 26 amps of 120 volt power. Allowing a safety margin, the transformer should be a 4 kilowatt model.

At 480 volts you need two transformers, step up at the start of the line and step down to 120 (or 120/240) at the far end. You can afford to lose 19 volts (the same 4%) along the way. This gives you 25 amps of 480 volt power down the line or 100 amps of 120 volt power (or 50 amps of 240 volt power) at the far end. To take advantage of it all you need 14 KW transformers (allowing a safety margin).

For wires rated at 600 volts you may not run a multiwire branch circuit (using all 3 wires) with transformer step up to 480 to 600 volts hot to neutral and 960 to 1200 volts hot to hot (and step down to1 120/240 at the far end). At any rate, the circuit, MWBC or not, needs a ground wire. For up to 60 amps on any one conductor the ground wire (equipment grounding conductor) can be #10 for short distances but I don't know how much upsizing is needed for the distance involved.

If you use transformers and step down to both 120/240 volts (MWBC) at the far end with a transformer with center tapped secondary, you only need two conductors plus ground running the 1400' distance.

(Based on a round trip line resistance of 0.75 ohm for the #4 gauge wires.)
 
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