The first thing I would look for would be internal fuses blown. This sounds like a 460 volt 12,000 watt industrial generator and you probably should call the installing contractor for service. My 15,000 watt generator is over 30 years old and has less than 700 hours on it and those are mostly test-run hours.
Check and replace the spark plug, clean filters and try again. If this doesn't fix it, it is probably the carb. Clean it and try a SMALL squirt of starter fluid