no but it will save on your power bill since the 220 is more efficent
Does this air conditioner require 220 volts?
Absolutely not.
The power supply for the Sunpentown WA-1340DH Portable Air Conditioner/Heater Combo is 115V / 60Hz.
Yes.
In the U.S. you should be using 110-115V.
no
The voltage is OK, but the current the A/C draws will govern the size of the circuit wiring and receptacle configuration. If the A/C unit is under 15 amps, a regular 15 amp receptacle can be used. If over 15 amps then a bigger size wiring will be needed depending on the amperage draw of the unit.
A 50 volt 60 Hz transformer would work well at 100 volts 120 Hz, because the peak flux density in the core would be unchanged. Provided the insulation remained OK the VA rating of the transformer would be doubled. Running it at 115 v 60 Hz would probably damage the transformer even on no-load because the core losses would be increased a lot with the flux density running at double the designed amount.
Your electrician is correct on this. However, the pump is designed for 230V and will use less electricity, thus saving money if wired for 230V. Yeah, if you have to rewire for 230 V then it would be more expensive until your savings had consumed or offset the expense.
If you live in an area that uses 115V as the mains supply, then it's absolutely fine. Equipment sold in the area will be designed to operate on that voltage and there is no difference in performance between 115V equipment and 230V equipment.
No, the circuit should not be energized when checking the resistance of a circuit.
Yes, all wall receptacles are rated at 125 or 130 volts.