Points heater – Type SMDC1

Switching module for DC 750 V up to max. 2A


The switching module is the power section of the points heater controller of the latest generation.

Each switching module controls a heating rod and monitors its function.
The switching module communicates with the superordinated controller (part No. 640100) via a two-wire bus.

The switching module consists of a power section and a control section.
The power section switches the heating rod and monitors the current through the heating rod for being above or below the set values. The heating rod is switched off if impermissible values are found.

An IGBT is used as the switching element.

The control section is based on a microprocessor.
This is responsible for communication with the superordinated controller and evaluation of the switching and error states.

If there there is a short circuit or a breakage, an error message is created and transmitted to the superordinated controller.
Between 1 and 99 switching modules can be operated at a superordinated controller, whereby addresses 90-99 are reserved for special functions (e.g. DC 750 V switch cabinet heating).

The current amount of current drawn is learned by the switching module with a new heating rod (initial commissioning or replacement). The warning and alarm limits are set from the value that has been taught in and then saved in non-volatile memory.

The connections for the auxiliary power supply and data bus are located in the base of the housing and contact is made via a plug system in the top hat rail during installation.

The high-voltage connections are located in the upper part of the housing and are in the form of screw terminals.

The required safety clearances and distances are maintained as a result of this design.

Do you have any questions?
We will be happy to answer you!