Substations

A 138/13.8kV Class H substation with two substation transformers supplied by two overhead transmission lines O-1315 and W-2249.

Half the substation (the 138kV bay) shall be upgraded to 230kV.  Scope also includes the removal of all 138kV equipment and structures and the upgrading of the bay associated with Substation Transformer T1 to 230kV.

The new substation located on the Con-Ed Poletti site provides the interface point between the new Astoria II Power Plant and NYPA. A 345kV aerial transmission line feeds gas-insulated switchgear (GIS) arranged in a ring-bus configuration with four circuit breakers (with provisions to accept two additional feeders). The ring bus serves Con-Ed high pressure fluid filled feeders via overhead aerial cables and bus located in the adjacent switchyard. Two 150MVA shunt reactors were relocated from the decommissioned Poletti Generating Station and installed in the new switchyard.  In addition to installing all the GIS and switchyard power distribution equipment, E-J also installed all associated controls, instrumentation, and metering.

E-J’s scope also included a complete fit-out of all building services including lighting, power, mechanical, BMS, security, fire alarm and communications.  Due to environmental remediation of the soil, the project schedule was compressed to include peaking at 120 electricians with 2 shifts a day, 7 days a week.

The Grasslands Substation project called on E-J Electric to provide the complete “above grade” electrical package. The work within this scope included the rigging and placement of switchgear, a complete 3000A/4500A bus duct system, installation and termination of all control and power cables, placement and wiring of all control room equipment, (2) 500kVA station power transformers, complete fire alarm system, complete public address/paging system and completion of two 138kV/13.8kV transformer bays which included welding of cable bus, installation and adjustment of circuit switchers and circuit interrupters and all 125VDC control devices.

The station was completed on an aggressive schedule, made challenging by one of the areas most severe winters. This was the first time that Consolidated Edison Co. contracted this complete scope of work.