Looking for a proper grounding method from source feeder conductors through metal conduit and a disconnect to a separately derived source with a secondary conductor service to new load.
I want to install a ground conductor with the feeder conductors to a disconnect for the high side of a separately derived source transformer. From the disconnect on the high side to the transformer container, I am using a flexible metallic tubing with metal flexible connectors. On the secondary side of this transformer the neutral is grounded which includes the container of transformer. This ground conductor is then distributed with the new voltage loads.
From the disconnect to the high side of the transformer I am questioning if I have to connect this source ground conductor??? When looking at it on paper, I still see a loop being created through the metal frame of the transformer container and the conduit back to the disconnect. I do not want to create any loops in the system when I connect the new grounded electrode with my system ground of the building. I have to protect the high side conductors to create the low impedance requirement for tripping the source breaker. I also have to create the same type path for the secondary source. This way the new distribution system breakers have their low impedance path.
It appears that a break in the conduit between either the disconnect or after the separately derived source should be incorporated to prevent loops ? since it is required to bond all ground electrodes or grounded electrode conductors.
I do not have a NEC Handbook ? but I do recall it had a diagram for this type installation. If anyone has this available and can forward a copy it might help.
Thank you ALL? This forum is an excellent resource.
I want to install a ground conductor with the feeder conductors to a disconnect for the high side of a separately derived source transformer. From the disconnect on the high side to the transformer container, I am using a flexible metallic tubing with metal flexible connectors. On the secondary side of this transformer the neutral is grounded which includes the container of transformer. This ground conductor is then distributed with the new voltage loads.
From the disconnect to the high side of the transformer I am questioning if I have to connect this source ground conductor??? When looking at it on paper, I still see a loop being created through the metal frame of the transformer container and the conduit back to the disconnect. I do not want to create any loops in the system when I connect the new grounded electrode with my system ground of the building. I have to protect the high side conductors to create the low impedance requirement for tripping the source breaker. I also have to create the same type path for the secondary source. This way the new distribution system breakers have their low impedance path.
It appears that a break in the conduit between either the disconnect or after the separately derived source should be incorporated to prevent loops ? since it is required to bond all ground electrodes or grounded electrode conductors.
I do not have a NEC Handbook ? but I do recall it had a diagram for this type installation. If anyone has this available and can forward a copy it might help.
Thank you ALL? This forum is an excellent resource.