PROFIBUS-DP Transient Suppressor and Anti-Surge

The SUP303 is a protective device against transients and surges in Profibus-DP networks. Easy to install on DIN trail, it can be connected on every network segment or node. It guarantees the integrity of Profibus signals against lightning, transients or voltage peaks. Whenever the effective distance is longer than 50m on the horizontal or 10m on the vertical between two grounded points, the use of SUP303 is recommended at both points;


  • In networks with high susceptibility to noises the SUP303 is recommended;
  • Works at 9.6 kbits/s to 12 Mbits/s;
  • Increases the Profibus network operational safety;
  • Increases Profibus network availability;
  • Can be used with Modbus 485.

Advanced technology for protection in three stages

The SUP303 uses advanced components that work in peaks of high voltage and short duration, high current, high voltage, low impedance with fast response and effective protection against ESD and EMI.

The SUP303 circuits were developed to provide effective and coordinate protection in reaction to a transitory at the Profibus-DP port. The primary stage protects from the exposition to an excess of transitory voltage, at a lower level. When the current transient exceeds the trigger limit, the second stage responds in microseconds, thus limiting the current. The third stage keeps the voltage within the Profibus-DP drive limits.

Technical Specifications


All variants of PROFIBUS RS-485: (DP, DP-V1, DP-V2, PROFIdrive, MPI, etc.)


Compliant with PROFIBUS EN50170 standard

IEC61000-4-2 (ESD)
IEC61000-4-4 (EFT)
IEC61000-4-5 (Surge)

Communication rates (kbps)

9.6k, 19.2k, 45.45k, 93.75k, 187.5k, 500k,1.5M,3M ,6M and 12M

Protection Levels

ESD (IEC61000-4-2)
Surge (IEC61000-4-5)
EFT (IEC61000-4-4)
Power Cross

Level of transient protection
Level 4 - 8 KV (contact) / 15 KV (air)
Class 3 - 25 A
Level 3 - 1KV
28Vrms & 120Vrms

ESD - Electrostatic Discharge
EFT - Electrical Fast Transient
Power Cross - via AC Powe

Work Direction

Line-Line and Line-Ground

Duration Time

≤ 500 ns


Tipo A – de acordo com a EN50170

Operation temperature

0 ºC to 60 ºC


Up to 90%

Protection Degree

IP-20 (DIN EN 60529 VDE 0470)


DIN35 rail (DIN EN 60715 TH35)


Cable up to 2.5mm² with connectors fixed with screws


90 g


75.0 x 22.5 x 104.4 (Height x Width x Depth) 

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