AVSparky
Member
- Location
- Los Angeles County, CA
We have 2 bath houses in an existing RV park and there is a fluctuating voltage potential between the floor drain and the shower valve. We have measured from 4 volts to 12.5 and people were getting shocked. I am not very experienced with MV transformers and the ground methods. I am trying to clarify that the existing grounding and bonding methods are correct. Here is a summary of the installation. The main service is 4160V WYE system feeding multiple 2400V - 120/240V transformers connected to each phase. The conductor is 15kV rated direct burial with a concentric neutral. There is no grounding conductor ran between the transformers. Each transformer has the neutral on the primary bonded to the case, low voltage XO terminal and Ground rod. The transformers have internal distribution section with multiple OCDs feeding out to RV pedestals and bath houses. My question is should the primary neutral be bonded to the case and XO. It appears there is a defective neutral underground on the primary side and we have voltage traveling through the earth back to the source. If this neutral was not bonded to ground then there would not be a potential to earth correct? This transformer and bath house is at the end of the line. There is a EGC running to the bath house sub panel from the transformer, the EGC, neutral, cold water, bath house GRC all bonded at the bath sub panel. I believe this is incorrect and the neutral should not be bonded creating a parallel path back to the transformer. We have identified another problem from the same transformer, a 120/240V sub panel fed from this transformer, when disconnected at the CB the voltage potential falls to around 5 to 6 volts. This sub panel is direct burial fed with no EGC from the transformer and feeds multiple RV pedestals the neutral and Grounds from the RV pedestals are bonded together at the sub panel but isolated from the panel with a nice piece of wood. Each pedestal has its own ground rod. The pedestals GRC and EGC are isolated from the neutral. Last thing, when all OCDs at transformer distribution are shut off ther is still a 5 Volt potential in the shower. Also the under ground waste plumbing is ABS not cast iron. I can supply wiring diagrams and photos if necessary. I can provide more info but don't want to overload this post.
Thanks for any suggestions or recommendations.
Thanks for any suggestions or recommendations.