RS-485 and 12V DC Bus Surge Protector Mounted on DIN Rail

SUG-RS485-12VDC/DIN is a dual device designed to protect the RS-485 bus and 12V DC power supply from surges caused by lightning strikes and potential differences. The internal connections eliminate surge voltages between any wires - including between RS-485 and power supply, thereby increasing the effectiveness of protection. This solution is dedicated to installations where the power supply and RS-485 are supplied to the same points.

The power circuit uses a 2-stage surge limiting action, while the RS-485 circuit uses additional solutions in the form of MOSFET fuses, which limit the flow of large surge currents. This results in increased durability and significant reduction of surge voltage reaching the protected device. An additional advantage of this solution is the limitation of equalizing currents, which can protect RS-485 interfaces from potential jumps that lead to overcurrent.

The structure consists of voltage clipping and limiting stages, as well as a current limiter above 300mA. The product has very low attenuation, making it possible to transmit data at very high speeds. The product also has a protected wire screen path.

The surge protector is designed to be mounted on a DIN 35mm rail. High-quality window clamps with high current load reduce the risk of damage during large shock impulses and temporary current overloads. The device occupies the width of one DIN standard module.

The product is recommended for installation at the boundary of LPZ0 and LPZ1 zones or higher.

Simplified internal diagram.

To ensure proper surge protection, it is recommended to use protectors at both ends of the transmission line and properly ground them.

Proper use of the product for protecting the RS-485 bus.

Short technical specification