Emergency power systems fill in utility gaps

Photo courtesy Russelectric.

Russelectric, a Siemens business, has seen its emergency power systems used by wastewater treatment plants (WWTPs) and other large, critical facilities around the world.

The systems, which are supervisory control and data acquisition (SCADA) capable, provide backup during a utility power loss. Their paralleling switchgear incorporates dual, redundant, hot-synchronized programmable logic controllers (PLCs).

Load demand sensing determines the number of engine generators in operation. The system permits first-priority loads to transfer to the connected engine generator set, while delaying the transfer of lower-priority loads until additional generator capacity has been connected. The lower-priority loads then transfer to the emergency power system as generator sets are added to the bus.

All systems are listed by Underwriters Laboratories (UL) and can offer peak shaving and load curtailment. Discrete switches, meters and control devices are standard to allow manual control capability in the event both system PLCs fail. A 23-in. liquid-crystal display (LCD) human-machine interface (HMI) touch screen enables operators to view system one-line diagrams, alarms and setpoints.