Solutions   for   Protecting   andManaging   the   Electrical   Network

NP.SC 800-1,   NP.SC 800-2

Network Check Synchronizing Relays

NPSC800-1 performs check of synchronism between two power supplies. It is usually used to authorize the closing order of a paralleling circuit breaker.
NPSC800-2 allows in addition the operating of live (or dead) line and live (or dead) bus. It also allows, with a dedicated output relay, the reconnection of two bus sections fed by the same supply.

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]
  • NPSC800-2: network managment function (live / dead line, live / dead bus)


  • Configuration and parameter setting by local MMI or off-line / on-line PC
  • Measurement of electrical quantities:
    – Phase voltages Ul, Ub
    – Frequency Fl, Fb
    – Voltage difference (Ul – Ub)
    – Angular difference
    – Frequency difference (Fl - Fb)
    – Acceleration (Hz/s)
  • 2 setting groups, locally or remotely selectable by digital input or by the communication channel
  • Self-diagnosis: Memories, output relays, A/D converters, auxiliary supply, cycles of execution of software, hardware failure
  • NPSC800-1: 3+1 assignable output units / 4 assignable digital inputs
  • NPSC800-2: 7+1 assignable output units / 8 assignable 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/RTU® RS 485 or Ethernet by Modbus/TCP


  Device Doc. Type Lang. Ref. Index
Leaflet EN A413 G
First Handling Guide EN A415 C
User Manual EN A417 F
NPSC800-1 Connection/Definition Diagram EN / FR S38893 E
NPSC800-2 Connection/Definition Diagram EN / FR S39609 B