Solutions   for   Protecting   andManaging   the   Electrical   Network

NP.RG 810

Generator Synchro-check relay

NPRG810-1G performs check of synchronism between a generator and an electrical network. It is usually used to authorize the closing order of a paralleling circuit breaker.
NPRG810-4G performs check of synchronism between one to four generators and an electrical network.
These two devices are fitted with dead busbar paralleling function.

As well as the usual protection functions, NP800 relays provide monitoring, measurement and recording of the electrical quantities of the network. The relays can be set by the RS232 port, or remotely using the RS485 port.
Reading, measurement and recording are all available locally or remotely.


  • Synchro-check [25]
  • Dead Bus paralleling
  • Adjustment of the phase shift between GE and BB measurements (Step up transformer adaptation)
  • Network configurable rated voltage


  • Configuration and parameter setting by local MMI or off-line / on-line PC
  • Measurement of electrical quantities:
    – Phase voltages Uge, Usb
    – Frequency Fge, Fsb
    – Voltage difference (Uge - Usb)
    – Angular difference
    – Frequency difference (Fge - Fsb)
    – Rate of frequency change dF/dt (Hz/s)
  • NPRG810-4G: 4 settings tables available for management of 4 generators
  • Self-diagnosis: Memories, output relays, A/D converters, auxiliary supply, cycles of execution of software, hardware failure
  • NPRG810-1G: 3+1 output units / 4 digital inputs
  • NPRG810-4G: 7+1 output units / 8 digital inputs
  • Event recording: 250 locally recorded events, 200 saved in case of loss of auxiliary supply
  • Disturbance recording according to Comtrade┬« format: storage of 4 recordings of 52 periods
  • Optional Communication by Modbus┬« RS 485 or Ethernet by Modbus/TCP


  Device Doc. Type Lang. Ref. Index
NPRG810 Leaflet EN A419 E
First Handling Guide EN A421C C
User Manual EN A423C C
NPRG810-1G Connection/Definition Diagram EN / FR S39371 B
NPRG810-4G Connection/Definition Diagram EN / FR S39610 A