Protection and control

The PCMU MSOC is the most powerful, advanced and simplest

feeder protection relay in its class, offering time and instantane

ous overcurrent, negative sequence overcurrent, phase discon

tinuity, breaker failure, thermal overload, and voltage metering

and protection. The relay features optional high impedance fault

(HIZ) and sensitive earth fault (SEF) protection for grounded and

ungrounded distribution systems. The relay incorporates a flexi

ble three-phase multi-shot auto-reclose function for automatic

feeder restoration in temporary faults on overhead lines.

The PCMU MSOC integrates basic control functionality, which

facilitates the control of one circuit breaker via the relay’s front

panel human machine interface (HMI) or remote control system.

To protect the relay from unauthorized access and to maintain

the integrity of information, the relay has been provided with a

four-level, role-based user authentication system, with individual

passwords for the viewer, operator, engineer, and administrator

levels. The access control system applies to the front panel

HMI, embedded web browser based HMI, and the PCM600

relay setting and configuration tool.