The EziArc140i is designed to operate on a 10A 230V AC power supply.
If an extension cord must be used, it should be minimum cable core size 2.0mm2 for length of up to 10m, or minimum 2.5mm2 for length up to 20m. Using extension leads of over 20m is not recommended.
This machine has a wide input power variation tolerance (~170-265V), allowing it to operate off generator power. Ideal generator capacity is 7kVA. A suitable quality generator should have a THD (total harmonic distortion) rating of less than 6%. Most reputable generator suppliers will be able to specify the THD ratings on their product.