On Board Lightning Arrester

Lightning Arrester

10kA and 20kAmp Lightning Arrester 

The Mersen lightning arrester enclosures are designed to protect railway networks against disturbances incurred by lightning, in the feeding lines in the substations along the railtrack (pole enclosure) as well as in the power lines mounted on the roof (pantograph enclosure). These protection systems are to be intalled between the feeding line and ground. The usual solution consists of placing an air breaker and a non-linear resistance in silicium carbure between the line and the ground. The system presents several drawbacks : It does not age well, and it becomes passing after several operations. This malfunction triggers the opening of the line circuit breaker, which interrupts the service. The new solution is made up of the combination in series of a non linear zinc oxyde resistance and a current limiting fuse. The zinc oxyde resists better to ageing thanks to a better non linearity coefficient. In spite of this, should a lightning surge be violent enough to damage the lightning arrester, then the fuse will isolate the faulty equipment, leaving the feeding of the railway line in service. One of the essential elements of the system is that it is the first with a distant warning signal of the lightning arrester being isolated. The railway network operator has the advantage of detecting very rapidly the protections. Mersen proposes to use a zinc oxide varistor combined with a fuse and an electric signaling system. Thanks to this system, it is now possible.



  • To vastly improve the quality of power line protection by better peak let-through in overvoltage conditions. This is due to zinc oxide’s non linearity factor, which is more suitable than silicon carbide’s.
  • To eliminate the now superfluous air spark-gap because leakage current is significantly reduced, making it easier to install the product.
  • To lengthen the product’s life span and improve peak let-through over time, because ZnO retains its initial properties better and longer.
  • To avoid disturbing operation when the product has aged due to lightning striking too many times or too hard.
  • To simplify maintenance. The defective device is immediately isolated and the blown fuse detection device trips a micro-switch to give remote warning of the state of the system. The element to be replaced is identifi ed immediately.
  • Operation : Instantaneous automatic, self-restoring, no power follow current, only voltages spikes clamped.
  • Connections : No 8 AWG cables for plus and minus terminals.
  • Gapless: no series components other than surge suppression fuses.
  • Power consumption: none except few milliamperes for indicator lamps and relay coil.


  • Voltage Range (VAC) 500 - 750 VAC
  • Application Railway networks protection against disturbances incurred by lightning
  • ROHS Compliant Consult Technical Services
  • Lead Free Consult Technical Services
  • CE conformity Yes


Where to buy


© 2018 Mersen S.A. All rights reserved.