Power generators' requirement for IRC 5 controller

Hi,

We are looking at operating the IRC 5 controller (with IRB 4600) through a power generator (e.g. diesel or gasoline power generator) due to plant limitation of 3-phase fixed line power supply.

Based on the "Product specification - Controller IRC5", the voltage requirement is as follows:
1. 200-600 VAC (+10%, -15%), 3-phase, 48.5 - 61.8 Hz   OR
2. 220/230 VAC, (+10%, -15%), 1-phase, 48.5 - 61.8 Hz
with controller rated power of 13 kVA.

Question 1:
Based on the above listed voltage requirement, am I right to say that the current requirement for power generator could be calculated as follows:
1. For 3-phase, the current is approximately 22-65 A   (i.e. 13 kVA / 200 V,  13 kVA / 600 V) 
2. For 1-phase, the current is approximately 56-60 A   (i.e. 13 kVA / 220 V, 13 KVA / 230 V)

Question 2:
If my assumption in question 1 is valid, then line fusing of 25 A (for 400-600 V) or 35 A (200-220 V) seems to be lower than the current limit. Do I missed out something?

Question 3:
If we were to operate the IRC 5 controller through power generator, what are the requirement that we need to take note? (e.g. current limit, voltage and current stability, etc)

Appreciate your help and advice.
Thank you.