PM 250 over-voltage relay

- overvoltage protection for fans containing a delayed damper opening or a time switch with PTC element
- rated voltage 230 V/50 Hz
- ambient temperature 0-50 °C
- is built in a plastic housing, which can be placed under the switch
- has a non-reversible overload fuse
- IP40 protection
- dimensions 51 × 30 × 12 mm (W × H × D)

Used when fans are connected together with fluorescent lamps without compensation capacitors, which produce high overvoltages in the installation. These overvoltages of 2-6 kV will normally destroy the built-in PTC members of the fan. It is mounted between zero and the control phase.