I am working on a 10 story hotel that was struck by lightning. I have replaced all service equipment,sub-panels, feeders, etc. The local utility has replaced their pad-mount xfrmr. The building is fed with two 2,000 amp nema 3R Siemans switches with GFI and shunt trips. These each feed a 2,000 amp MDP, one for heating/cooling load, the other for lighting and general use. The problems I am haveing involve the grounded conductor on the heat panel. Panel is fed from switch with 5 sets of 500mcm with a 250mcm ground in each set. While checking nuetral current, we discovered that each nuetral conductor had a different load, with a difference of up to 80 amps. Further checking revealed that the nuetral current at the main switch is non existent, however I am showing about 20 amps at the ground rod, and about 15 amps at the water ground. This is going on while pulling roughly 1,400 amp on the service. Service is 480/277wye, all equipment is new, and grounding is well above NEC requirements. My question is...if I have no current on the nuetral, and only 15-20 amps on the ground, WHERE is the nuetral current going. I have had 3 master electricians and 2 electrical engineers on this for a week, we have checked and rechecked everyting we can think of, and have gotten nowhere. Any suggestions?
Richard
