Circuit Protection

Circuit Protection

Mors Smitt offers a wide range of railway hydraulic magnetic circuit breakers. The circuit breakers are fully configurable to meet individual requirements.


  • Precise, temperature stable mechanism, due to hydraulic magnetic technology
  • Overcurrent sensing mechanism reacts only to changes of current
  • No ‘warm-up’ period to slow down its response to overload. No ‘cooldown’ period after overload before it can be reset. Derating considerations due to temperature variations are not normally required and heat-induced nuisance tripping is avoided
  • A common trip linkage between all poles, another safety feature, ensures that an overload in one pole will trip all adjacent poles
  • A trip-free mechanism, a safety feature, makes it impossible to manually hold the contacts closed during overcurrent or fault conditions
  • Standard dimensions, mounting and current ratings provide maximum application versatility
  • Wide range: current ratings to 700 Amps and rated voltages to 600 VAC and 110 VDC are available
  • Options: series trip, mid-trip, switch only (with or without auxiliary switch), remote shutdown, shunt trip, and dual coil circuit options are available


The Mors Smitt minature circuit breakers are designed according the following railway

  • IEC 60077 Electrical equipment for rolling stock in railway applications
  • EN 50155 Electronic equipment used on rolling stock for railway applications
  • EN 45545-2 Fire protection on railway vehicles
  • NF F16-101/-102 Fire behavior - Railway rolling stock
  • IEC 61373 Shock & vibration resistance - Railway rolling stock