I'm certainly not an electrician but one of expert around this web can help. I recently come across the problem where the ground volts raised up to 12 volts and UPS system (10KVA) was stopped working due to ground issue. Some electricians came but unable to find the actual cause then I ask from expert consultant, he send a technician who bond the generator neutral to mains neutral (remember that the generator is using as a primary source). Is this correct solution of the problem