For a wastewater treatment plant, nothing is more important than preventing a sanitary sewer overflow. An unintended sewage overflow would bear public health, ecological, and economic consequences.
electrical power reliability
From an operating standpoint, the influent pumping station of a wastewater treatment plant plays a vital role in ensuring the flow of influent sewage throughout the plant’s disinfection processes. Thus, ensuring the reliability of electrical power to the influent pumping station is vital.
Washington Suburban Sanitary Commission (WSSC), a strong proponent for meeting and exceeding environmental standards, selected Helios Electric to design a new electrical system for their influent pumping station at the Parkway Water Resource Recovery Facility.
intelligent switchgear controls
To meet WSSC’s expectations, the engineers designed a solution to maximize reliability with intelligent switchgear controls using SEL protection and automation devices. Design features included:
- Automatic Source Transfer: In the event of a power disturbance of an incoming electrical utility supply, the intelligent switchgear controls are automatically transferred to the alternate electrical supply to ensure continued operation of the influent pumping station. This scheme also considered transfer timing with the existing upstream main substation and the downstream motor control centers.
- Bumpless Source Restoration: Once a disturbed incoming utility supply was restored and proven, the intelligent switchgear controls automatically retransferred to the normal “redundancy operation” mode using closed-transition, make-before-break, and synchronism-check transfers without the need for disrupting the ongoing influent pumping station operations.
- Integration with SCADA System: The intelligent switchgear controls were tied into the existing SCADA system to enable real-time monitoring of electrical conditions at the influent pumping station. This included monitoring the health of incoming utility supplies, the status of circuit breakers, and alarm annunciation of faulted components. With SCADA integration, any anomaly would immediately be known 24/7 at the centralized WSSC headquarters to facilitate the prompt dispatch of qualified personnel to ensure continued operations at the influent pumping station.
To establish a reliable electrical distribution system and to safeguard public health, it is important to implement intelligent switchgear controls.
