The ZH437 K-H series are tripping devices that integrated with auxiliary switches. The series provides effective thermal cutout protection from overheating machine such as electric air heaters. The air heaters are commonly used in rail vehicles and stationary heating systems.
The tripping devices of the series are required for fire protections, and can be operated independently without the heater controls. Before installation, they must be fitted with fusable links that meet the number of trip temperatures require in your application.
The series must be wired into the heater load circuits. Overheating of the system happens when the air flow is not enough or heater control malfunctions. Once the required temperature of the fusable link is exceeded, the devices will shorten the heater load circuit.