Sir,
Allow me to give you some additional insight as to what I am dealing with. I am a licensed electrical contractor in the United States working on a military installation in Afghanistan. My job entails taking spot generation loads and connecting them to what we call prime power, this is provided by a large central power plant. The distribution system for prime power is 4160V installed underground throughout the base and stepped down with a typical transformer that you would see in the United States to 120/208 Volt 60HZ. These are the circumstances I am dealing with and are incorrect but the persons above me have the opinion that I am in error.
1 - The persons above me are applying Article 450 to what we would call in the States the utility transformer connection on the secondary side.
3 - The persons above me are insisting that a EGC be run with the service lateral between the utility transformer and the first OCPD based on Article 250.122.
4 - The persons above me are insisting that in addition to the EGC being ran with the service lateral that a bonding jumper be installed within the enclosure of the OCPD? Creating objectionable current and potential hazard.
6 - My belief with the EGC installed with the service lateral is a very poor practice because the only overcurrent protection of the lateral is the secondary fuse of the transformer, which is not designed for this purpose. It is my belief that the installed EGC will fail during a fault allowing the condition to remain.
I do have a very good understanding of the NEC but looking for guidance to deal with this unusual situation.
Thank You
Sounds like an awkward situation at best.
Under the NEC the transformer would fit in as a POCO service transformer or as a customer operated SDS depending on where it fell on the dividing line between NEC and NESC. In your case I would have to say that which approach you take will have to depend in part on what wiring practices were used for the primary feed to the transformer.
You have not stated whether the 4160 has a wire or earth neutral return or whether there is an EGC as part of the run. Nor have you detailed whether there are, as I assume there would be, adequate (under the NEC) ground electrodes at each load site.
At low (<600) voltages a simple earth connection, no matter how well the ground rods are driven, cannot be counted on to clear a line to ground fault. That is the job of the EGC which has a lower, known and measured impedance back to the source. If the secondary OCPD is in your opinion inadequate, you may need (make that "want") to run a larger EGC.
The utility is allowed to create a situation where a line to ground fault on the secondary side, within the service wiring itself, will not be effectively protected by any OCPD. That is their problem and their choice to do. (One reason that service wiring is allowed inside the building only to limited extent.)
Not providing an EGC in your case will only make the situation worse. Bonding the neutral to the EGC and/or local ground electrodes should be done at only one place; in a standard installation it would in the vicinity of the service point. Bonding the neutral to the EGC for an SDS should also be done at only one place, typically at the secondary neutral tap of the transformer.