Hello, I recently ran into a strange case with a building connected to a transformer with delta secondary at 600V. It appears a quasi neutral is formed by a connection to a ground plate. Meter stacks were later connected to this system and discovered not to function due to the lack of a proper neutral.
The transformer and main service entry are nearly at end of life and I'm working with the (new) site electrician to build a case to toss all of this and rebuild it properly. In my intial report I'm citing the code issues and I see some pretty significant violations here!
In my view this is an ungrounded system since there is no solid (or impendance) connection to ground on any current carrying conductor. This would then fall into section 10-400 which requires ground fault detection. No such protection exists. Rule 10-402 calls for a low impedance connection between source equipment and grounded service equipment, which may or not be present. To make matters worse the transformer (nearly 2MVA) is very close to the service gear leading to my concern about fault levels / flash risk with no easy return path for the fault.
The situation looks to me to be quite non compliant and potentially very dangerous. If anyone has comments or insight to offer please reply back.
Thank you.
The transformer and main service entry are nearly at end of life and I'm working with the (new) site electrician to build a case to toss all of this and rebuild it properly. In my intial report I'm citing the code issues and I see some pretty significant violations here!
In my view this is an ungrounded system since there is no solid (or impendance) connection to ground on any current carrying conductor. This would then fall into section 10-400 which requires ground fault detection. No such protection exists. Rule 10-402 calls for a low impedance connection between source equipment and grounded service equipment, which may or not be present. To make matters worse the transformer (nearly 2MVA) is very close to the service gear leading to my concern about fault levels / flash risk with no easy return path for the fault.
The situation looks to me to be quite non compliant and potentially very dangerous. If anyone has comments or insight to offer please reply back.
Thank you.
