I recently purchased a 2 HP irrigation pump. I have the option to hard wire this in 110 or 220. Which is better and/or cheaper? My previous 1.5 HP pump was wired as a 110.

According to the National Electric Code, the circuit should be sized to Table 430.148, which lists a single phase 2 HP motor drawing 24 amps at 120 volts or 12 amps at 240 volts.

If the motor is fed with 240 volts, #12 copper wire may be used. If 120 volts is delivered, then #10 wire will be required.

So the benefit of using 240 volts is smaller wire, which will save money on the purchase of materials and the labor to install heavier wire.

Best to provide 240 volts to this motor using 12 wire up to 150 feet. If the cable will be more than 150 feet, now #10 will be needed to reduce voltage drop.

Using 240 volts instead of 120 volts does not save any money for cost of electricity.