What wire gauge is needed to connect a 6500 watts generator 200Ft away from switch. 50A at 120 v.?

Question

What wire gauge is needed to connect a 6500 watts generator 200Ft away from switch. 50A at 120 v.?

Answer 1

Is the switch the only thing located 200 ft away? Does the switch carry the full 50 amps?

PS, 6500/120 is actually 54 amps.

#6 wire is 0.4 ohms per 1000'

That's 0.16 ohms per 400' (200 x 2)

At 50 amps that is 8 volts drop, which is a little high, as you should be <5% which is 6 volts.

#5 wire is 0.31 ohms per 1000'

that comes to 6.2 volts drop.

That's pretty heavy wire.

http://www.powerstream.com/Wire_Size.htm

Answer 2

The ampacity rating of the wire depends on the raceway you place the wire in and the insulation of the wire. See Ref attachment.

I recommend the 6AWG with the 75deg rating wire which is more common. Basically, welding cable works well, which is also flexible if this is a temporary condition. If a more permanent installation go with the THHW or THWN type wire.

Answer 3

The current for this generator is 6500/120 = 54 amperres.

A no.6 AWG copper insulated wire could carry the load without overheating but, since the unit is 200 ft away from the switch, a No.22 MM2 copper wire is suggested.

Its reistance is0.843 ohms per km

Hence Voltage drop =I(0.843/1000(3.28/1000)(400)

                                    = 54(0.843)/3.28)(0.400)

                                    = 414..18

The expected voltage drop is excessive. so we try using 60MM2 or 1/0 copper wire, resistance is 0.304ohms/km

Voltage drop using 60mm2 wire = 54{400](0304)/1000{3.28/1000} =54{0.16]

                     = 8.64 volts.

Therefore  No 60mm2 or 1/0 copper wire is recommmended.

Answer 4

If you need all 50 Amps, then you need at least 8 gauge wire.

I don't believe they make 6 gauge extension cords, but I have seen 8 gauge cords.

FYI: With 10 gauge, at 200 feet, you will get too much voltage drop.  If it was 50 feet or less you could probably 'get away' with 10 gauge.

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