Free Sensor Sample Order Now

Interface-Protector GEL 855xx



  • Electromagnetic immunity
    - Burst (as per EN 61000-4-4) 4.4 kV
    - Surge (as per EN 61000-4-5) > 1.25 kV
  • Protection against an offset on the potential of up to
    - 10 Veff AC with maintenance of communication
    - 50 Veff AC


  • Reliably protects the downstream hardware against
    damage due to an offset on the potential, e. g. in case of
    a lightning strike.
  • Uninterrupted availability of the communication with the
    protected device.
  • Quick to fit, as no additional cabling required.


  • The Protector 485 is a surge arrester for connection to an RS485 (half duplex), a PROFIBUS interface or a CAN bus interface.
  • In case of offsets on the potential of up to 10 Veff AC (caused, e.g., by earth loops) the electronics are protected and communication is still maintained. As a result data transmission is not interrupted even under very difficult conditions.
    Only in case of offsets on the potential of more than 10 Veff AC (caused, e.g., by a lightning strike) is the communication interrupted for the duration of the interference while the electronics are fully protected.
  • As an intermediate device, the Protector is connected directly to the interface of the device to be protected without further cabling. Due to the low series resistance in operation, a terminating resistor can be left in the device protected.
  • Due to its compact design with a width of 22.6 mm, the Protector can be placed in a control cabinet with minimum space requirements.
  • The marked field on the adhesive label of the Protector may be used to affix an equipment ID label.

  • Speed of response in the nanosecond range
  • Series resistance approx. 10 Ohm
  • Internal circuit designed for high pulse energies, caused
    by lightning strike

Fields of application

  • Wind power (onshore, nearshore, offshore)
  • Harsh industrial environment

Technical Data

Electrical data
Power supply Passive component
Electromagnetic immunity
   Burst (according EN 61000-4-4)
   Surge (according EN 61000-4-5)
> 4.4 kV
> 1.25 kV
Protection class IP 20
Serial interface GEL 85500: RS 485 (half duplex), PROFIBUS
GEL 85510: CAN bus
Connection Screw-type terminals
Ambient data
Operating temperature -40 ºC ... +85 ºC
Storage temperature -40 ºC ... +85 ºC
Condesation no
Maximum atmospheric humidity 95 %, yearly average 75 %
Maximum operating altitude 3000 m
Vibration resistance acc. to DIN EN 60068-2-6 20 m/s2, 9 to 50 Hz
Mechanical data
Dimensions (W x H x D) 22.6 mm x 99 mm x 92 mm
Weight 80 g