Corporate| Railway | Industry

Protection relays

Basic functions:

  • Minimum voltage relays
  • Maximum voltage relays
  • Differential voltage relays
  • Minimum current relays
  • Maximum current relays
  • Differential current relays
  • Interval voltage relays
  • Frequency protection relays
  • Phase sequence relays


  • High galvanic separation
  • No auxiliary supply needed, stand alone
  • High reliability, no maintenance due to reliable and proven electromechanical technology
  • Strong ability to withstand high overloads
  • Equipped with weld no transfer
    contacts for critical applications

For On-Board applications:

  • Traction brake monitoring relay
  • Traction overcurrent relay
  • Traction isolation breakdown relay
  • Catenary min. voltage detection relay
  • Catenary max. voltage detection relay
  • Wheel slip relay
  • Insulation breakdown relay
  • Battery monitoring relay
  • Motor/alternator monitoring relay
  • Pre-load filter detection relay
  • Ground fault detection relay

For Trackside applications:

  • Directional current detection relay (reverse current detection in power distribution)
  • Catenary voltage (1500V) detection relay
  • 3rd rail voltage detection relay
  • Substation ground fault detection relay
  • Heat tracing cable surveillance relay
  • Current overload relay (15000A)

Voltage, current, ground & insulation fault detection relays
Voltage, current, ground & insulation fault detection relays
  • Protection relays are often the last barrier to protect rolling stock and trackside equipment in the event of upstream protection system failure. They do not require auxiliary supply. Their mechanical life of 100 million operations exceed train life.
Explore the product portfolio

Mors Smitt Group worldwide

Regional sales offices
Mors Smitt B.V.
Vrieslantlaan 6
3526 AA Utrecht
The Netherlands
T: +31 30 288 1311
Mors Smitt Asia Ltd.
21/F., 9 Des Voeux Road West
Sheung Wan, Hong Kong
T. +852 2343 5555
RMS Mors Smitt
6 Anzed Court
Mulgrave,VIC 3170
T: +61 (0)3 8544 1200
Mors Smitt France SAS
2 Rue de la Mandinière
72300 Sablé-sur-Sarthe
T: +33 243 92 8200

Mors Smitt Technologies Inc.
1010 Johnson Drive
Buffalo Grove, IL 60089-6918
T. +1 847 777 6497
Mors Smitt UK Ltd.
Graycar Business Park
Barton under Needwood
Burton on Trent
DE13 8EN
United Kingdom
T: +44 1283 722650
Local sales & support offices
Mors Smitt Sales & Support - Brazil
Sao Paolo, Brazil
Mors Smitt Sales & Support - Gulf Region
Abu Dhabi, United Arab Emirates
Mors Smitt Sales & Support - Malaysia
Kuala Lumpur, Malaysia
Mors Smitt Sales & Support - China
Zhongshan, P.R. China
Mors Smitt Sales & Support - India
Bangaluru, India

© Mors Smitt 2018

Your feedback is valuable for us