‍Oil Circuit Breaker (OCB) Replacement

To mitigate the consequences of a 138kV OCB failure and PCB contamination, Rally designed the replacement of the OCBs with a new SF6 breakers.

Electrical Building Replacements & Expansions

Rally designed the replacement of existing 5kVoutdoor substation control buildings complete with equipment as the existing facilities were nearing end-of-life. In some facilities, footprint allowed for expansion of existing buildings in lieu of replacement.

Substation Upgrades

During a transformer replacement, Rally incorporated at the request of the utility a back-up circuit breaker and isolation switch which included new 138kV dead end structure, 138kVmotorized switch, and surge arresters upstream.

Substation Expansions

A power system study indicated that several parts of the electrical system were underrated. Underrated equipment cannot safely interrupt electrical faults and can therefore fail catastrophically in case of an electrical fault. Rally designed the expansion of the tubular bus system and all associated apparatus to extend the substation.

Transformer Replacements & Upgrades

Multiple replacement or upgrades of existing transformers (due to age, PCB contamination, or capacity increase requirements) along with neutral grounding resistor and associated protection panel have been executed by Rally.

Substation Conductor Failure Mitigation

A failure on underground 5kV power cables required temporary power cables to be installed at grade to restore operation to the facility. The execution of this project was expedited as the temporary cables were in violation of the applicable regulatory electrical codes and standards. It was determined that a new incoming switchgear cell was required as the existing cell was not suitable for the installation of top-entry, shielded cables.