800' Aerial Run with Buck/Boost Transformer

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rasbaboo

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I'm looking at an 800' aerial run + 120' underground feed (3/0 AL) . Using Quad Cable 1/0 Aluminum (3 wires w/ messenger cable). Voltage is 3 phase 240/120 w/ a Stinger leg. Anticipated load is around 75 Amps for a walk in cooler compressor (3 Phase 50 Amp) and other smaller motors - single and 3 phase. I'm thinking of installing a multi tap buck / boost transformer to compensate for the voltage drop. Need help on what boosted voltage I'd need to compensate. What voltage would I need to run #2 Al Quad Cable in lieu of 1/0 Al ? All this because the local power providers are incapable of mounting their own transformer on their own pole after a new permitted electrical service and a properly submitted and approved application.
 
iwire

iwire

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Location
Massachusetts
In my opinion that is not the way you need to go.

If you boost the voltage with the buck boost high enough under full load conditions you will have serous over voltage during times of little load.

You are likely better off using a normal transformer at the source raising the voltage to 480 or 600 volts and then using another transformer at the far end to drop the voltage back down to what you need.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
iwire said:
In my opinion that is not the way you need to go.

If you boost the voltage with the buck boost high enough under full load conditions you will have serous over voltage during times of little load.

You are likely better off using a normal transformer at the source raising the voltage to 480 or 600 volts and then using another transformer at the far end to drop the voltage back down to what you need.
Click to expand...

I agree with iwire, you are going to have voltage issues, even if you do individual buck/boosts for each load, instead of the total load. You still will have unacceptable voltage swings.
 
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rasbaboo

Member
OK

OK

Thanks for the quick response! Good feedback about the wide voltage swings. I didn't think about that. What I'm trying to do is buy some time, as cheaply as possible, until the utility Co. sets their T former on the pole. The 120' underground feed is already in place (3/0 Al). Do you think the 1/0 AL Quad Cable (180 Amps) that has 3 wire + messenger as neutral, could power just the walk in cooler compressor? I don't have the actual nameplate or wattage info, but it is fed with a 3 pole 50 amp breaker. Probably draws 35-40 amps. It might be cheaper to bribe the utility co. to start running their business like a foreign car company.
 
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