Resistive relay 16A DIN rail CR-810 CR-810DUO

Resistance relay CR-810DUO is a reliable device designed for electrical protection against overheating. It utilizes PTC thermistor sensors, connected in series (from 1 to 6 pieces), to monitor temperature and disconnect the circuit if the permissible value is exceeded. This solution is ideal for installers and users who want to protect their devices from damage caused by excessive temperature.

Functionality and application

This relay is used wherever protection against the effects of overheating is required – in heating systems, motors, transformers, and industrial equipment. Its operation is based on the change in resistance of the PTC sensors depending on the temperature. An increase in resistance above 3000 Ω triggers the relay and opens the circuit, indicated by a red LED. The system will automatically re-engage when the temperature drops below 1800 Ω. An additional function to protect against short circuits in the sensor wires (resistance below 70 Ω) also causes the relay to switch off and a light signal.

Construction and mounting

The device is designed for mounting on a standard 35 mm rail and occupies only 1 module (18 mm wide). It is made of high-quality materials, ensuring its durability and reliability. Electrical connection is made using screw terminals with a cross-section of 2.5 mm², and the tightening torque is 0.4 Nm. The relay has a NO/NC switching contact with a maximum current load of 16A and provides galvanic isolation of the contacts. The supply voltage can be 230 V AC or 24 V AC/DC. The device's power consumption is only 0.8 W.

Additionally, it is worth mentioning the optical signaling of the operating status: a green LED indicates correct supply voltage and temperature of the controlled device, as well as the efficiency of the PTC sensors. Operation in a temperature range from -25°C to +50°C and a protection class of IP20 guarantee the possibility of use in various environmental conditions.