Hello again..
Has everyone forgotten about you??
Ok, PROVIDED you have an OCPD [fuse or whatever] rated at 100A at the generator end to protect the cable, you need a 35mm 4 core cable assuming that it is going to be installed underground [either directly in the ground of in a duct] How the cable is installed you see, makes a difference, as it affects the cooling of the cable.
I have selected this cable size, assuming a thermoplastic cable designed to run at 70c. Most cables now are thermosetting ones, and can run at 90c, but this is a bit pointless, as most "accessories" are only rated for 70c.....
Arrangements for earthing and fault protection the others will advise you on, as their knowledge is FAR greater then mine.
One thing i do not have a clue about is earthing and fault protection for generators, because, one thing you have to achieve in the event of a fault, is the required "disconnection time" both in the event of an earth fault, and also in the event of a fault between live conductors.
The disconnection times as regards earth faults are as required by the regulations, [it will be 5 seconds for your circuit]
However, you also have to make sure that the OCPD operates fast enough in the event of an fault betweeen live conductors......
I think people tend to forget about this, as there are no set times, but so far as i can recall, all the calculations in the big book as regards the heating effect in the cables in the event of a fault, are based around a disconnection time of UP TO 5 seconds. If you exceed this, the cables COULD be damaged.
What concerns me, is that to check on this, you have to know what the prospective PEFC and PSSC are. I have no idea if a generator can put out enough fault current to operate the protective devices as intended. With the mains you would just measure the circuit impedance to check, not sure if you would get a valid reading with a generator..... No idea......
Over to the professionals i think!!!!
john...