CRITEC® DEP Series – Equipment Surge Protector


Equipment Surge Protector

The DEP Series (Equipment Surge Protector) is designed to protect equipment connected to serial protocol systems from the damaging effects of induced surges and transients. The DEP protectors are packaged in male-to-female DB9 and DB25 cases for simple installation at the serial ports of terminal equipment.


  • Premium 1500 Watt (>100 Amps) simultaneous capability for 8/20µs test pulse
  • Simple plug-in protection
  • Models to cover RS-232, RS-423,RS-422 and RS-485 protocol applications
  • Both “line” to “signal-ground” and “signal-ground” to “protective-earth” modes protected
  • A flying earth lead is provided for connection to protective earth
  • Where existing wiring/pin configuration is unknown DEP RS232/25/25 is available to protect all wires


Protection of RS-232, RS-423,RS-422 and RS-485 circuits such as:

  • Serial printers and modems
  • Point-of-sale equipment
  • Communication/programming interfaces to computerized industrial equipment (PLCs, SCADA etc)
  • Security communications links (RS422

More Information

Application Example
CRITEC DEP Data Equipment Protector Application

Ordering Information

Part No. Part No.
for Europe
DEP RS232/25/25 700630 RS232, DB25, 25 wire protector, 15V working
DEP RS232/9/9 700640 RS232, DB9, 9 wire protector, 15V working
DEP RS422/9/9 700650 RS422/485, DB9, 9 wire protector, 9V working


Technical Note TN CR 004, How to select SPD’s for data, signal and control circuits