Substation Construction

Substation Construction Project: Tonkawa, Oklahoma, Kay County Section 33, T26N, RlW Latitude: 36.673616, Longitude: -97.306758 The City of Tonkawa is seeking EPC (Engineer, Procure, Construct) proposals for the expansion of their 138- 13.2kV substation (operating at 69 kV) by adding a second 138/69-12.47/7.2 kV power transformer identified as the North Transformer. The scope of work is as follows: o Create all construction drawings for the following equipment and construction. Provide two (2) sets of printed "As Built" drawings to the City of Tonkawa within 3 months after completion ofthe project. DWG format and PDF format drawings shall be provided on electronic media to the City of Tonkawa within 3 months after completion ofthe project. o Engineer, procure, and install the transformer foundation with concrete oil containment with oil sensing relay and sump pump plus fiberglass walking grates all around the transformer prior to December 24, 2022. o Engineer, procure, and install all remaining foundations, ground grid expansion, fence expansion, 138 kV Bus expansion (operated at 69 KV) 12.47 kV bus expansion including feeder bays, 12.47 kV Bus PT's, lightning protection, underground conduit, control cable installation and termination, substation yard lighting, installation of substation rock, equipment testing, relay programming, substation site cleanup, and commissioning ofthe substation. o Engineer, procure, and install all required steel structures. o Procure and install a total oftwo new 138kV candlestick type circuit switchers, one for the existing south transformer and one for the new north transformer. o Procure and install a new 138 kV disconnect switch for the north transformer. o Procure and install one new 12.47 kV bus circuit breaker for the new north transformer low side protection. o Procure and install a minimum 12' x 12' control building, concrete or steel. o 125 VDC battery bank and charger, flooded nickel cadmium or lead acid preferred. Other systems may be approved based on an engineering analysis. Battery Charger shall communicate with the SEL RTAC. o Engineer, design, and provide AC power, DC power, and control signals to all new and existing substation yard equipment and new relay devices from the new control building. o Connect the new North Transformer, Delta-Grounded Wye, 138/69-13 .2/7.62 KV, 12/16/20MVA transformer with LTC to the expanded 138 kV Bus (operating at 69 kV) and the existing 12.47 kV bus. The transformer will be provided by Tonkawa Energy Services and set in place, assembled, and tested by the transformer manufacture. o Install a SPX nitrogen generation system or approved equivalent for the proposed North Transformer and for the existing South Transformer installation. SPX uitrogen generation system is not required on the spare transformer. o Split the existing 12.47 kV low side bus to balance the load across the north and south transformers. Install a load-break 1200-amp gang operated tie switch to connect the north bus to the south bus as a normally open switch. o Replace existing low side circuit recloser controllers with SEL 651R controllers with fiber optic cable and transceivers to communicate to the SEL RTAC. o Expand the overhead static wire lightning protection as necessary to protect the 138 kV bus expansion, North Transformer T2, Control House, and fencing. o Test, program, and commission all relays, circuit breakers, and circuit switchers. o Using an SEL LTC controller (part #24110lBOXIA73850400), wire the LTC of both transformers to be operated remotely from the control house and SCADA. o Move the existing fence and expand the ground grid to allow for new equipment installation a s needed. o Electrically test the existing south transformer's bushings, arrestors, gauges, LTC, and auxiliary equipment. Inspect for nitrogen leakage and possible gasket replacement. Inspect control cable wiring and terminations. Overall visual inspection of the south transformer. o Provide and spread substation gravel within the substation yard and 3' outside the fence. o Add 25 KVA station service transformer to the north 12.47 kVbus for 2nd source to the ATS. Tonkawa will provide the station service transformer. o Relocate the existing spare 69- 12.47 kV transformer outside the north existing substation fence to make room for substation expansion

Division 26 -

Electrical.