EM series motor protection On/Off switches can be supplied in 10 setting ranges from 0.3 to 16 amps. In addition to thermal triggering, the switch can also be supplied with quick KA magnetic triggering or UA low-voltage triggering. Operation by means of insulated T-handle is via a robust switching latch with rotary drive. In the version with low-voltage triggering the EM switches ensure the protection called for in the DIN EN 60204 Part 1 provisions against automatic restarting when power is restored following a power cut. The nominal frequency is 50 Hz. Switches for other voltages with a frequency of 50 or 60 Hz can also be supplied on request.
The MN series motor protection switches are cam switches with thermal over-current trip devices integrated within the switch. The base unit forms the contact chamber with the cam wheel for function control. In the event of excess current, the bi-metals cause the switching latch to be operated via a trip shaft. This interaction enables a multitude of switching programmes with integrated motor protection to be produced. Due to the switching of the bi-metals within the current circuit there are 2 different series in terms of the setting ranges: for On/Off switches, reversing switches, pole-changing switches (1 rotary speed protected) and single-phase starter switches 12 setting ranges of 0.3 to 21.5 amps have been defined.