Solutions for Switch Heating Control

Switch heating systems make a vital contribution to the operational safety of railway and tram networks. Snow, ice, and freezing precipitation can impair the movement of a switch, leading to operational disruptions. At the same time, switch heating systems are among the most energy-intensive consumers within railway infrastructure.

The challenge is to activate the heating system only when weather conditions actually require it. If heating is switched on too early or operates for too long, energy consumption and operating costs increase. If activation occurs too late, the risk of service disruptions and manual intervention rises.

For many years, KELAG has been supplying sensor solutions for switch heating control, supporting railway operators and system integrators in the selection, integration, and commissioning of the appropriate measurement systems. The foundation of every modern switch heating control system is precise weather and rail temperature data measured directly on site.

For controlling a switch heating system, the rail temperature is often a more meaningful parameter than the ambient air temperature.

The KSTF11ASBK rail temperature sensor has been specifically developed for installation on railway tracks and measures the actual rail temperature directly at the rail. This provides the control system with an accurate representation of the infrastructure's thermal condition.

The measured values can be integrated directly into PLCs or supervisory control systems and used as an input for the switch heating control logic.

In addition to temperature, precipitation plays a crucial role in switch heating control.

Snow, rain, and freezing precipitation significantly increase the risk of ice formation in the switch area. Reliable precipitation detection enables the switch heating system to operate only when critical weather conditions actually occur, ensuring efficient, demand-based control.

Depending on the project requirements, different solutions are available - from simple precipitation sensors with switching outputs to complete weather stations with digital communication interfaces.

Depending on the existing infrastructure, control system, and project requirements, KELAG offers a range of solutions for acquiring all relevant measurement parameters.

The KWSS16.1 has been specifically developed for applications where simple and robust integration is the primary requirement.

Measured Parameters:

Interfaces:

The KWSS16.1 is particularly suitable for conventional PLC applications where switching signals are processed directly.

The KWUS13.4 provides the same essential weather information as the KWSS16.1, but makes it available through analog interfaces.

Measured Parameters:

Interfaces:

This solution can be easily integrated into existing control and automation systems that require analog input signals.

For more demanding applications, the KWDT08.1 provides a fully featured weather station.

In addition to temperature and precipitation, further meteorological parameters can be measured and transmitted to the control system via Modbus RTU.

Measured Parameters:

Interface:

Depending on the project requirements, additional sensors can be integrated to measure further meteorological parameters such as relative humidity, wind speed, or wind direction.

The KWDT08.1 is particularly well suited for advanced control strategies where multiple weather parameters need to be considered simultaneously.

A modern switch heating control system typically consists of a weather station combined with one or more rail temperature sensors.

The sensors transmit their measurement data to a PLC or supervisory control system, which determines whether to activate the switch heating based on the defined control logic.

Thanks to the wide range of available interfaces, the sensors can be seamlessly integrated into existing railway infrastructure and control systems.

The solutions offered by KELAG have been used for many years in switch heating control applications and have proven their reliability under a wide range of climatic conditions.

Depending on the location, topography, and the number of switches, different system concepts can be implemented. At smaller sites, a single weather station combined with a rail temperature sensor is often sufficient. Larger installations, however, typically require multiple measurement points to ensure accurate monitoring across the entire area.

Today, KELAG's sensors and weather stations are in operation with various railway operators across Switzerland, providing the reliable measurement data required for efficient, demand-based switch heating control.

Thanks to many years of field experience, KELAG supports both straightforward retrofit projects and complex system integrations in close collaboration with railway operators, engineering consultants, and system integrators.

Reliable switch heating control starts with precise measurement data.

Only the combination of rail temperature, precipitation, and additional weather parameters enables a well-founded assessment of the actual conditions on site. This allows switch heating systems to be operated on demand and unnecessary heating periods to be avoided.

With the KWSS16.1, KWUS13.4, KWDT08.1, and the KSTF11ASBK rail temperature sensor, KELAG offers a modular system for acquiring all relevant measurement parameters and integrating them into existing PLC and supervisory control systems.