DEP – Data Equipment Protection


Data Equipment Protection

The Data Equipment Protector has been designed to protect serial I/O interface equipment 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. For RS232/423 circuits, DEP models will allow peak working voltage of up to 15 volts, with 9 or 25 pin protection. For RS422/ 485 circuits, the DEP RS422/9/9 allows up to 9 volts working, and is packaged in a DB9 case. A flying earth lead is provided for connection to protective earth.


  • Premium 1500 Watt (>100 Amps 8/20µs) capability – robust protection
  • Models to cover RS-232, RS-423, RS-422 and RS-485 protocols
  • Provides both line to signal-ground and signal-ground to protective-earth protection
  • DEP RS232/25/25 protects all wires – circuit wiring/pin configuration does not need to be known
  • Plug-in protection – simple to install
  • ERICO Surge Products are covered by an extended warranty; see the attached document for more information


  • 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

Part No. Description
DEPRS2322525D RS232/423, DB25, 25 wire protector, 15VDC
DEPRS23299D RS232/423, DB9, 25 wire protector, 15VDC
DEPRS42299D RS422/485, DB9, 25 wire protector, 9VDC


LAN & DEP data sheets

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

Surge 5 Year Warranty