Electric voltage drop

I am not shure on using the voltage drop calculators. When they ask for the total distance, round trip, what do they mean ? I am running 240 volt from my generator 175', 2 conductor and neutral, would it be 175, 350, or 525 for the total length ? 50 amps service and I figure on using aluminum.

Round trip I would say is 350'

using aluminum 2awg at 50 amps the voltage drop would be 4.56%. so at 240V you would get 229.051 out the other end of the line. I would consider 2awg the smallest to use. If you upgrade to a 2/0 wire you only have a 2.27% drop.

the 2awg would be easy to handle. If its going to be a stationary install go with the 2/0 it will serve you better.

If you go with copper the 2awg would get you a 2.34% drop....... Aluminum may be cheaper but its less efficient.

The price for aluminum thhn single is $0.30/ft for 2 gauge, and $0.49/ft for 1/0 gauge, the 1/0 may be my choice, what do you think of the price ??? Is their a flexable conduet for underground, I want to use the pvc rigid, but would like to be close to the surface at the foundation without a l & b box to be seen, and the possability of freezing pushing up the pipe to crack, and water entering the foundation inside the pipe. Will do at least 18 " deep.

AA130FIREMAN wrote:The price for aluminum thhn single is $0.30/ft for 2 gauge, and $0.49/ft for 1/0 gauge, the 1/0 may be my choice, what do you think of the price ???

I don't know the pricing, but did you price XHHW (better known as SE) cable vs. that single THHN?

SE = Service Entrance

McGiever wrote:

AA130FIREMAN wrote:The price for aluminum thhn single is $0.30/ft for 2 gauge, and $0.49/ft for 1/0 gauge, the 1/0 may be my choice, what do you think of the price ???

I don't know the pricing, but did you price XHHW (better known as SE) cable vs. that single THHN?

SE = Service Entrance

Yes, service entrance in 2 gauge aluminum is $0.93/ft , I wil use service entrance inside, but 2 gauge ??? Outside direct bury 2 is $0.88/ft but I like having it in pipe, just don't want water inside the foundation

Sounds like a good price for the 1/0.

As far as the conduit. I do not know much about that. But I would use Metal conduit if you are planning to go shallow. I personnely would only burry PVC if I was going down a few feet or more. Emt is cheap, not sure if its under ground rated in your state with out additional galvanic protection. I would use not less then 2" to ensure you can pull it easy, and have room for more wires down the road. Or if you decide to upgrade and install larger wires.

AA130FIREMAN wrote:

McGiever wrote:

AA130FIREMAN wrote:The price for aluminum thhn single is $0.30/ft for 2 gauge, and $0.49/ft for 1/0 gauge, the 1/0 may be my choice, what do you think of the price ???

I don't know the pricing, but did you price XHHW (better known as SE) cable vs. that single THHN?

SE = Service Entrance

Yes, service entrance in 2 gauge aluminum is $0.93/ft , I wil use service entrance inside, but 2 gauge ??? Outside direct bury 2 is $0.88/ft but I like having it in pipe, just don't want water inside the foundation

I have never opened an underground conduit that did NOT have water in it, even plastic w/ solvent weld couplings. But you could turn up a 90* bend and then go inside w/ a LB fitting to get around the water getting inside the foundation.

Ironically, the pipe keeps the water in and not out.

Could I keep the LB fitting level with the topsoil, top cap up just at surface level to keep it out of sight. My thought was to use pvc rigid, 90 up at foundation,then a flexable piece into the foundation underground to keep out water.

AA130FIREMAN wrote:Could I keep the LB fitting level with the topsoil, top cap up just at surface level to keep it out of sight. My thought was to use pvc rigid, 90 up at foundation,then a flexable piece into the foundation underground to keep out water.

Sure, the 90 was more the point.

Try using the voltage drop calculator calculator on the rommex web site.

i had 240ft 80amp run to generator its 18" by code, buried conduit so i believe from what i understand is that you have to go larger when in conduit because the heat is trapped, and then due to voltage drop another size up. i believe its #2 rated for 125amp cooper. Aluminum you have to go another size up, but if its not in conduit you can go with a size down.

or my electrician is selling me a crock o shiz.

The pvc is rigid but it does 45 bends ok, he explained to me something about code not allowing more than 360 in 90s and so he didnt want more than 2 - 90deg in the path. i had to go around a 16ft 1000gal propane tank.The connector they use at the house is actually somehow spring loaded and flexible.

Electrical red tape went in about 10" as the ditch was being backfilled.

You have to go up in size if several runs are bundled together as well. Guess they must interact the way a coil does, inducing voltage in the other.

Heat...
% filled...

I would go with copper wire. Corosion at the connections can be a problem with aluminum. I see that even electrical entrances are going with copper. If you use aluminum wire be sure to use No-Al-Ox paste worked into the bare wire strands at the connections with a wire brush. This definately helps reduce corrosion.

... and with Al torque it properly and then again in two weeks. Al wire to my 5 ton air unit caught fire as it was loose and I got lucky.