What size wire do you need for 50 amp sub panel about 150 feet away 120 volts?

Answer 1

The usual allowable voltage drop is 5%, or 6 volts on a 120 v supply. For a 50 amp supply that means the total wire resistance must be (at most) 6/50 ohms, or 0.12 ohms. Because there is 300 ft of wire the resistance per ft must be 0.12/300 ohms per ft, or .0004 ohms/ft or 0.4 ohms per 1000 ft. Wire tables show that #6 AWG wire is needed, with a cross-section area of 13.3 sq mm.

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Answer for USA, Canada and countries running a 60 Hz supply service.

The code book suggest that a 3% voltage drop should be the maximum allowed. A #3 copper conductor will limit the voltage drop to3% or less when supplying 50 amps for 150 feet on a 120 volt system.

Answer 2

For a 50 amp sub panel located 150 feet away at 120 volts, you would need to use a 6 AWG copper wire to ensure proper voltage drop and safety standards are met. This wire size is adequate to handle the current and distance without significant voltage drop. Be sure to consult local electrical codes and regulations for specific requirements.

Answer 3

If it's a 50-amp panel designed for 100 percent full-time load at 120 volts, you would plug those numbers into a voltage-drop calculator and it will tell you.

A #3 AWG copper conductor pair in conduit, overhead or direct burial will give you 85 Amps with only about 3.6 volts (3 percent) voltage drop.

#4 AWG would give you 4 percent drop (at max current).

#6 AWG would give 6 percent drop, but only 3.6 percent at 30 Amps.

Answer 4

min of # 6 thhn copper