Surge arrester for RS-485, SUG-7 / RS-485

SUG-7/485, surge protection for RS-485, dedicated to industrial automation and CCTV. Protection RS-422

The SUG7 / RS-485 is a high-effectivity RS-485 bus protection against damage caused by atmospheric discharges and all kinds of overvoltages. Eliminates and discharges large electrical loads (up to 10kA) to the ground and also eliminates the potential between individual transmission line wires (inside wires).

It utilizes an innovative super-fast MOSFET fuse that further protects RS-485 drivers against current impulses of potential differences between individual devices and overload due to short-circuits or overloads.


Protection RS-485

Simplified diagram

When there is a current increase of more than 100mA, the circuit between the input and output in SUG7 is disconnected at 1µs. Once the threat has been resolved, the connection is also restored within 1µs.

Due to the possibility of overvoltage from any side, it is recommended to connect the busbar to the 2 ends, which increases the response speed and protection level. The SUG 7 should be grounded by individual grounding point or by PE line - it is important to ensure that the discharge path to the ground is as short as possible.



How to protect RS-485

Correct surge protection of RS-485

SUG-7 / RS-485 can also be used to protect the RS-422 bus. In this case, use 2 times the number of protections - one for RS-422 TX and the other for RS-422 RX.

Technical specification:
Maximum overvoltage level
4kV
Protection level line-ground (8/20μs)
2x10kA
Protection level line-line (8/20μs) 100A
Protection level line-shield (8/20μs) 10kA
Protection levels
3
Capacitance of circuit
100pF
Maximum current for RS-485 100mA
Tightness of the housing
IP20
Reaction of MOSFET fuse
1μs
Dimensions 74 x 32 x 25 (mm)
Work temperature
-40~+60°C