I have two 1800 kVA emergency standby generators that can parallel the utility. When either engine, alone or in parallel, is in parallel with the utility, I have excessive amounts of third harmonic neutral current. This will cause the utility and generator breakers to trip on ground faults. I have verified that I have same pitch generators(11/16). I am concerned that my utility transformer is to blame. I currently have a 1500kVA wye-wye transformer with both the primary and secondary neutrals grounded. It has been a concern that the high side neutral should not be grounded. I am in the process of trying to have the Utility transformer changed to a 2500kVA delta-wye. Do you think this will help?
Red Flag Submitted
Thank you for helping keep Eng-Tips Forums free from inappropriate posts. The Eng-Tips staff will check this out and take appropriate action.
Reply To This Thread
Posting in the Eng-Tips forums is a member-only feature.