Voltage relays
voltage detection, catenary voltage detection, threshold control, etc.
Applications and operation
These relays are used in applications such as voltage detection, catenary voltage detection, threshold control, voltage monitoring of battery chargers, etc.
In this kind of relays, the coil, vaccum impregnated or covered with an insulated resin, has an electrical resistance usualy between 100 and 40 000 Ohms.
These relays cover a current range from 10mV to 10 000 Volts.
These relays, associated with classical or specific components (non-linear resistors, rectifiers, transistors, zener diodes…), have led to a considerable number of very different realizations.
Moreover, the relay operation points can be made adjustable, either by the use of micrometric adjustment contacts, or by the addition of a second winding, additional or subtractive, controlled by a rheostat.
Catenary voltage presence relay
In trackside installations, for DC traction networks (750 | 1500 | 3000 Vdc), this relay is used to detect the presence of catenary voltage in the cells from the rectifier. The high insulation resistance (up to 12 KV 50hz) offers a high resistance to overvoltages, especially natural phenomena (lightning). In addition, no auxiliary power is required
Options available
- Faston 5mm, Faston 6.3mm, single or double
- Screw terminals for eyelet lug M4, M5, M6
- Push-in type insulated connector
- Other possible solutions on request

Cross sectional view
1- Contact normally closed
2- Moving armature
3- Contact normally opened
4- Magnetic circuit
5- Permanent magnet
A- ALNICO MAGNET
B- RARE EARTH MAGNET