DEHN BUStector BT 24 Surge Arrester for 2-Wire Bus Systems, 24 V DC, DIN Rail Mount, Red

Unlike generic surge protectors that only guard power lines, the DEHN BUStector BT 24 is purpose-built for data and signal integrity on 2-wire bus systems. It shields RS 485, PROFIBUS DP, CAN bus, LON bus, and EIB/KNX networks from transient overvoltages while preserving high-frequency signal quality up to 10 MHz. With a compact DIN rail housing and screw terminals, it integrates cleanly into control cabinets and field installations.

Highlights

• Protects 2-wire bus systems: RS 485, PROFIBUS DP, CAN bus, LON bus, EIB/KNX
• Nominal voltage 24 V DC, max. continuous operating voltage 28 V DC
• Voltage protection level ≤ 60 V line-line and line-PE
• High cut-off frequency approx. 10 MHz for minimal signal distortion
• Low series resistance 1.5 Ohm per line
• Compact red thermoplastic housing for 35 mm DIN rail mounting
• IP20 protection, operating temperature -40 °C to +80 °C
• Complies with IEC 61643-21 and EN 61643-21

In daily use

Install the BUStector BT 24 directly at the entry point of your bus cable into a device or cabinet. Connect the two signal wires and the protective earth to the screw terminals. During normal operation, the arrester remains passive and transparent to the bus signals. When a surge occurs, it diverts the excess energy to ground within nanoseconds, clamping the voltage to a safe level. The low series resistance and high cut-off frequency ensure that even high-speed bus protocols operate without bit errors or reflections. The red housing provides quick visual identification in the control cabinet.

Full specifications

• Protection type: Surge arrester for 2-wire bus systems
• Nominal voltage (Un): 24 V DC
• Max. continuous operating voltage (Uc): 28 V DC
• Nominal discharge current (In) (line-line, 8/20 µs): 1 kA
• Nominal discharge current (In) (line-PE, 8/20 µs): 1 kA
• Total discharge current (Itotal) (8/20 µs): 2 kA
• Voltage protection level (Up) (line-line at In): ≤ 60 V
• Voltage protection level (Up) (line-PE at In): ≤ 60 V
• Cut-off frequency (fG) (3 dB) line-line: approx. 10 MHz
• Series resistance per line: 1.5 Ohm
• Operating temperature range: -40 °C to +80 °C
• Mounting type: 35 mm DIN rail (EN 60715)
• Connection type: Screw terminals
• Housing material: Thermoplastic
• Housing colour: Red
• Protection degree: IP20
• Standards compliance: IEC 61643-21, EN 61643-21

Final note

The DEHN BUStector BT 24 delivers reliable surge protection for critical bus communication, ensuring uninterrupted data transmission even in harsh industrial environments.