Convert Transformer Supply from 34.5kV to 69kV

Tangibl was requested by the client to provide detailed design services for the conversion of supply to a dual winding (69/34.5kV-13kV) distribution transformer at an indoor substation in an urban commercial district near a major U.S. city.  The work involved replacing primary equipment as well as protection and control packages with telecommunications provisions.

Tangibl prepared detailed design drawings for review, and issue for construction (IFC) submittals.  Primary work included replacement of the existing 34.5kV Coupling Capacitor Voltage Transformer (CCVT) with a 69kV CCVT, and existing 600-ampere manually-operated disconnect switches with 1200-ampere, double side break, Motor-Operated Disconnect (MOD) switches.  Tangibl provided engineering documentation for the power and control wiring to operate the MOD disconnect switch.

The existing electromechanical transformer protection package (67/51TC, 27/59, 47) was replaced with a microprocessor-based package including a GE UR-D60 relay.  Tangibl provided engineering documentation for the protection and control wiring for replacement of the protection package.  Finally, a C37.94 interface was established between this substation and the next substation one bus away, including insertion of a GE JungleMUX node at the substation.  Tangibl provided engineering documentation for wiring the JungleMUX including a fiber jumper from the D60 relay to the JungleMUX C37.94 port.