SSR relay with heatsink for DIN rail 30A, zero-cross switching, control 230V AC 77.31.8.230.8050

Silent Control of Industrial and Heating Circuits

In locations where traditional electromechanical relays fail due to noise, arcing, or limited contact life, a semiconductor solution becomes essential. This specific model is a modular SSR (Solid State Relay) designed for mounting on a standard 35 mm DIN rail. Its primary function is the safe and precise switching of AC loads up to 30 A in the AC-1 category. By employing back-to-back SCR technology, the device eliminates physical contacts, resulting in zero mechanical vibration and complete absence of spark generation during switching. This is critical not only for quiet operation but, above all, for safety in environments where arcing could pose a hazard.

Switching Precision and Voltage Versatility

A key feature of this relay is the zero-crossing function. This means the device does not switch the load at an arbitrary point in the voltage waveform but waits for the zero-crossing point. Why is this important? For resistive loads (e.g., electric heaters) or halogen lighting, abrupt voltage switching generates massive inrush currents. Zero-crossing switching eliminates this effect, significantly extending the lifespan of both the relay itself and the connected receivers.

The device offers great flexibility regarding operating voltages. The control input accepts AC signals ranging from 40 V to 280 V (at 50/60 Hz), allowing direct connection to a standard 230 V network without additional intermediary components. On the output side, it supports circuits from 48 V to 480 V AC, with a rated load current of 30 A in the AC-1 category. Such a configuration enables control of loads in the range of several kilowatts, such as heaters for industrial furnaces or underfloor heating systems. It is worth noting that the device is single-phase and utilizes zero-crossing switching technology for maximum operational smoothness.

Mounting and Application in Automation

The modular design ensures quick and intuitive integration into control cabinets—simply lock the device onto the DIN rail. Screw terminals facilitate the connection of conductors with appropriate cross-sections, ensuring reliable electrical contact even at high operating currents. It is important to remember that, as a semiconductor component, it generates a certain amount of heat during operation (power losses at full load). Therefore, this model is equipped with a built-in heatsink or requires adequate ventilation within the cabinet to ensure ambient temperature does not exceed permissible limits (typically up to +80°C).

Practical applications of this solution cover a wide range of industries:

• Industrial automation systems for precise control of heaters and process furnaces.
• Electric heating installations and air conditioning systems requiring reliable switching of high power.
• Control of hall and street lighting, where priority is given to avoiding voltage surges when switching large loads.
• Specialized equipment requiring quiet operation and long service life without the need for regular mechanical contact maintenance.

Thanks to an input-to-output isolation level of 6 kV and an IP20 protection rating, the device meets safety requirements for internal installations in industrial and public buildings. Its resistance to switching cycles reaching millions of operations makes it a more durable alternative to classic electromechanical relays in applications requiring frequent switching of resistive loads.