Professional Services: Mechanical, Electrical, and Plumbing
The Substation Replacement project involved Bath Group Inc. providing analysis, design, construction support, and commissioning services.
The project included:
- Pre-fabricated substation building
- Power transformers
- Double-ended lineup of 5KV switchgear
- (2) Two 5KV motor control centers
- Substation battery system
- Power distribution systems
Bath designed and coordinated the installation of (2) 3,800ft 15KV feeder cables. The cables routed from the plant’s main substation to (2) new power transformers near the new Powerhouse. The new feeders allowed the unit to be powered from the plant’s 15KV power at a 20% energy savings. This new power routing also allowed the new Powerhouse to be placed in service without interrupting the operation of the existing power source. As a result, the motors and unit loads can be cutover with minimum disruption to unit operations.
In addition, Bath provided SKM modeling, coordination, arc flash, load flow studies and configuration settings for 30 protection relays including SEL model 751, 735, 787, and 710 units. Bath commissioned all of these devices along with the switchgear and motor control centers. While performing the SKM modeling, Bath discovered opportunities to introduce ERMS’s (Energy Reduction Maintenance Switch). ERMS’s reduce the level of incident energy in some of the existing low voltage equipment being re-fed from the new powerhouse. Levels greater than 40cal/cm2 reduced to less than 8 cal/cm2 for a significant improvement in operating personnel safety.
Bath’s design for the modern electrical distribution system improves the overall electrical safety and reduces operating costs and the risk of electrical power outages. By changing the power source for the A1 unit from utility-owned 5KV transformers to the in-plant 15KV power source, the project is expected to achieve 20% reduction in energy costs.
The design and construction of the substation replacement was completed without interruption to the operation of the plant. At completion, the total construction value was $9MM, which was $3MM under budget.