Need a lesson on distance amp/volt loss

BLHFUN

Well-known member
Ok, So I have 50 amp service to the pole, but I'm over 500 feet from that pole. last year I used over 300 hours of generator time and a ton a fuel and want to run 50amp service the 500 foot and plug in. I've talked to several people/electricians and they all say 500 foot will cause a ton of amp loss, which I'm ok with. But it starts a conversation about 50/30/20 amp service to my unit.

1. 50 amp service. What happens if I'm using 50 amp plugs, breakers, 8g wire and I loose 10 amps on the 500 foot extension?
2. 50 amp plugs, but 40 amp throughput.. Should I be concerned with my equipment or over heating my plugs/ connections?

It really boils down to my thinking about 50/30/20 amp service. I currently have my unit at home. It's 50amp from the unit, reduced to 30, reduced to standard 110 outlet on a 20 amp breaker. Working like a champ!

The real question, What's the difference between 50amps service and 40 amps delivered due to distance? These electricians are kinda freaking over the loss of 10 Amps, and I'm not sure I'm even using 15 amp total. Even if I'm getting 40, that's still way above the 20 that's currently working outside now? Should I be concerned with my equipment and low voltage? I think the answer is no!

What am I missing?
 

danemayer

Well-known member
I might be wrong, but I think you'll see a voltage drop rather than an amperage drop. You may see malfunctions and shutdowns below 105V. Motors and A/C compressors could be damaged.

To run 500 feet you might need something like #4 wire.

Sent from my SCH-I545 using Tapatalk
 

bdb2047

Well-known member
This is a voltage drop calculator from South Wire Co. Youcan put in what ever numbers you want and find wire size to get proper voltage at end.1 conductors per phase utilizing a #2/0 Copper conductor will limit the voltage drop to 4.54% or less when supplying 50.0 amps for 500 feet on a 120 volt system.For Engineering Information Only:
175.0 Amps Rated ampacity of selected conductor
0.1 Ohms Resistance (Ohms per 1000 feet)
0.043 Ohms Reactance (Ohms per 1000 feet)
6.0 volts maximum allowable voltage drop at 5%
5.437. Actual voltage drop loss at 4.54% for the circuit
0.9 Power Factor

**Note to User:All ampacity values are taken from the Section of 310-15 of the NEC. The conductor characteristics are taken from Table 9 of the NEC. The calculations used to determine the recommended conductor sizes for branch circuits are based on 60°C ampacity ratings for circuits rated 100 amps or less or marked for use with #14 AWG - #1 AWG. Circuits rated over 100 amps or marked for conductors larger than #1 AWG are determined using 75°C ampacity ratings. Calculations to determine service and feeder conductor sizes are based on overcurrent device ratings rather than actual expected loads which are conservative and may yield oversized conductors. No calculations take into account temperature correction factors or conductor de-rating.
This voltage drop calculator is applicable only to NEC applications. It does not optimize conductor sizes for several different loads at various points in a circuit. The total combined load and length of the circuit must be used. Consult with an engineer if your application requires more complex engineering calculations. Dan is correct voltage drop is what you see at end of run but the more the voltage drops the higher the amps needed.
 

avvidclif

Well-known member
Low voltage is what kills electric motors and other devices.

It's not the amperage that is the problem. It's the voltage drop. As the current goes up the voltage drops due to resistance in the wire. The more current you want to draw the larger the wire to keep the voltage drop at 5%. Add up what you want to run in the RV at that location and go from there. 30A service will run 1 A/C and the other usual stuff. If you want to run the full 50A service wire cost alone will exceed $5,000.

You didn't explain all the circumstances. If the pole is on your property and you want to run it on your property check with the electric company about an extension to where you need it.
 

BLHFUN

Well-known member
Thanks for the responses – Been on Google and South Wire’s Calculators this morning. It’s The Voltage that I needed to be concerned with and not the AMPS. I get that now.

The Electric Company brought a Single Service Pole up the property line about 650’ and dropped the pole on the fence line – It’s About 500 Feet from where I park. I had few concerns when they did this.

1 – The Farm is extremely rocky – Cost for single pole and100 Amp Service was very Expensive.
2 – To 90 that Pole and Extend to another Pole Closer to the pad.. TRIPLED the price.
3 – I didn’t want aerial RIGHT OF WAY through the property with a Pole in the scenery.

SO.. $5000.00 is cheap compared to the extended Pole service. They did give me the option of Direct Bury Lines, but we never discussed the cost because they Required a 4’ Deep trench.


I’m afraid the conversation I’m about to have with my wife…Ain’t gunna be good!

Thanks Fellas!
 

wdk450

Well-known member
Thanks for the responses – Been on Google and South Wire’s Calculators this morning. It’s The Voltage that I needed to be concerned with and not the AMPS. I get that now.

The Electric Company brought a Single Service Pole up the property line about 650’ and dropped the pole on the fence line – It’s About 500 Feet from where I park. I had few concerns when they did this.

1 – The Farm is extremely rocky – Cost for single pole and100 Amp Service was very Expensive.
2 – To 90 that Pole and Extend to another Pole Closer to the pad.. TRIPLED the price.
3 – I didn’t want aerial RIGHT OF WAY through the property with a Pole in the scenery.

SO.. $5000.00 is cheap compared to the extended Pole service. They did give me the option of Direct Bury Lines, but we never discussed the cost because they Required a 4’ Deep trench.


I’m afraid the conversation I’m about to have with my wife…Ain’t gunna be good!

Thanks Fellas!

Maybe its cheaper to move the RV pad.
 

avvidclif

Well-known member
If you want underground wiring your best bet is to get estimates from several companies including the electric company. It's not going to be a do it yourself deal. Do it once and do it right. You actually want the transformer as close to the breaker box as possible to reduce losses so they are going to have to go underground with the HV lines.

500' of extension cords will handle a light bulb, maybe......

It's a one time expense.
 

JanAndBill

Well-known member
Maybe its cheaper to move the RV pad.

When we built our house in a rural area, the cost to run 400 amp service to the house underground was huge, because they required it to be 4' underground. We compromised on poles up the drive way and stopping about 500' short of the house, the contractor installed the underground wiring from there to the house, for much less than the electric company was going to charge. However, I noticed you were talking 100 amp service. The requirements for a 50 amp service would be much less, and would be enough to handle your trailer load.
 

BLHFUN

Well-known member
When we built our house in a rural area, the cost to run 400 amp service to the house underground was huge, because they required it to be 4' underground. We compromised on poles up the drive way and stopping about 500' short of the house, the contractor installed the underground wiring from there to the house, for much less than the electric company was going to charge. However, I noticed you were talking 100 amp service. The requirements for a 50 amp service would be much less, and would be enough to handle your trailer load.

Agreed - The Well is about 20 foot from the Pole - I had the Main Throw at 100 Amps with the intention of running 50 AMPs to the Well house and 50 Amps to a Pedestal near the ToyHauler. – It gets hot in Missouri and I want a full 50 Amp service connected to the Trailer. If I do it right, It’s a onetime cost.. Just didn’t fully realize all the complexities of an extension.
 

Crumgater

Well-known member
I'm just a mechanical engineer... so double check this with a real electrician... but... couldn't you run a nice heavy wire out to the RV pad, and then put a voltage regulator / power conditioner on the end to boost the voltage back to 120V?

Grainger has some power conditioners rated at 20A
http://www.grainger.com/category/po...+conditioner&searchRedirect=power+conditioner

Power companies fix/boost voltage all the time on their long lines out in rural America.

-Tina
 

pegmikef

Well-known member
FWIW, My electrician had me run four single strands of #6 wire (neutral, ground, two hots) from my garage 350 feet to a building on my lake front for a sixty amp circuit (my garage has separate service). I used gray conduit and buried it about a foot and have had no noticeable voltage drop, but then I don't use any where near sixty amps. I broke it down in another breaker box into two 30 amp 220 volt circuits for my boat lift and sprinkler pump, plus several 20 amp light and outlet circuits. I just don't run the pump and boat lift simultanously. Never a problem. I doubt you would be using the whole fifty amps at any given time so you might get by with something like #2 wire. I had no requirement to bury it 4 feet since it was all on my property.
 
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