[ShaferMike]

Have a situation where I need to run an 110 amp 240 volt single phase circuit 1480 feet underground.

I am looking at running direct burial 350 MCM aluminum triplex for the length of the run. By my calculation, I see about a 10.5 % voltage drop which is unacceptable.

I believe the 350 MCM will yield a 10.5% +/- voltage drop while handling the amperage.

Considering using a 3KVA 10% boost transformer to take care of the VD, either at the line or load end.

Wire cost - benefit thing..

Any thoughts ?

Thanks

[Stratmando]

TK, maybe a couple of others can help with this.
I believe 5 % is max VD. He can help with what's allowed and may have a couple of tricks concerning boosting.
Or above ground poles?

[tkrussell]

I use the following formula:

Vd= 2 x length x amps x ohms per foot
Vd= 2*1480*110*.0000605
Vd=19.7 volts dropped or 8.2%

Max recommended allowed is 5% or 12 volts.

This may work OK if the load is resistance heat or incandescent lights.

The slightest loose connection will increase voltage drop.

The smallest motor will increase Vd when starting, and may still have problems starting.

You can try the buck/boost xfer, but I would recommend using step up and down transformers, 240/480 then 480/240. Even look into 575 volt primary.

Any voltage over 600 V will need special cable and attention, and cost.

You can use a 30 KVA standard dry transformer with a dripproof kit. Well two.