Electric heaters
are fitted to the railway track switches to prevent failure or malfunction of the switch
under conditions of ice or snow. The heaters are supplied from a single phase 240 V / 110
V isolating transformer, usually located at the trackside adjacent to the heater
installation. For safety reasons the isolating transformers are wound with dual secondary
windings each at 110 V and electrically separate from the other.The transformers are
petroleum jelly filled, and enclosed in an galvanised sheet steel tank to BS EN 60947
classification IP 54 or better. Typical ratings available are 3 kVA, 5 kVA, or 10 kVA.
All units comply with Network Rail/Railtrack specification RT/ES/40045 Issue 3 October
2001.
TEC also manufactures signalling and telecommunications transformers to BR
specification 924A.
