Solutions   for   Protecting   andManaging   the   Electrical   Network

PDZI 800

Railway protection for catenaries

PDZI800 performs the monitoring of AC railway catenaries feeders on conventional network or with autotransformers. This distance protection is fitted with overcurrent function and many operating function such as de-icing monitoring and control of operating of the circuit breaker.

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 locally, using either the keypad and display or the RS232 port, or remotely using the RS485 port. Setting, reading, measurement and recording are all available locally or remotely.


  • 3 downstream and 2 upstream zones of minimum of impedance [21]
  • Catenary undervoltage [27]
  • Directional with 2 thresholds [32]
  • Overcurrent with 2 phase thresholds [50] [51], with 2 switchable modes for each threshold
  • Circuit-breaker failure [50BF]
  • Differential de-icing [87]
  • 3 shot recloser [79] (optional)


  • Configuration and parameter setting by local MMI or off-line / on-line PC
  • Measurement of electrical quantities:
    – Instantaneous values of phase currents and voltage
    – Impedance Z, Resistance R, Reactance X, Angle PHI of the line
    – Harmonic ratio H2
  • Definite and dependent time tripping according to inverse, very inverse and extremely inverse IEC 60255-4 curves
  • 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
  • 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┬« RS 485 or Ethernet by Modbus/TCP


  Device Doc. Type Lang. Ref. Index
PDZI 800 Leaflet EN A509 D