The function of the devices in the RMSR 7900 series is to provide protection to three-phase electrical distribution networks against any form of short circuit between phases or between phase and earth.
They are modular in design and can be fully integrated into the PROCOM structure, or just as easily be used entirely independently in any other classical protection scheme.

The RMSR 7900 series incorporates two different devices:

• the RMSR 7991 meets the technical requirements of radial outgoing feeder protection in distribution networks.
  It makes use of a sensitive earth-fault unit and integrated auto reclose device to reduce supply interruption times resulting from transient faults.
• the RMSR 7992 is specially designed to protect incoming feeders in distribution system substations.
  Its protection functions allow selective operation with all types of protection installed downstream on the outgoing feeders (inverse or definite time).

PROTECION   FUNCTIONS

• Instantaneous [50] and time-delayed [51] phase overcurrent protection
• Instantaneous [50N] and time-delayed [51N] earth overcurrent protection
• Recloser Unit [79] (RMSR 7991)
• logical selectivity (RMSR 7992)

MAIN   FEATURES

• 3 programmable output units
• Programmable dependent or independent time curves
• Self-monitoring unit
• Measurements of phase and earth currents including harmonics up to 7th
• Settings via local HMI
• Modbus communications with Current Loop interface