Amps (I) = Watts (P) / Volts (V)
In this case, if the generator is operating at 120 volts, the amperage would be:
I = 5000 watts / 120 volts
= 41.67 amps
If the generator is operating at 240 volts, the amperage would be:
I = 5000 watts / 240 volts
= 20.83 amps