Contact us for an immediate quote at

Weatherproof Lightning Surge Protector for RS-422/RS-485 & 12VDC Power Lines




Import duties, taxes and any additional delivery or clearance charges, are not included in the item price or the quoted shipping cost. These charges are the responsibility of the Buyer.

Please check with your local customs office to determine any additional charges prior to purchase.

Continue Shopping or View Cart

The HyperLink ALS-D25P12DW is designed to provide superior lightning and surge protection for RS-422/485 control and 12VDC power lines. These protectors incorporate individual protection circuits for the RS-422/485 control lines and DC power lines. All housed in one NEMA rated weatherproof enclosure.

RS-422/485 Control Lines

A high power 3-stage design is used to provide protection for the RS-422/485 control line. The 3-stage design can handle higher-level transients than a protector that uses only diodes. The first stage is comprised of a differential gas discharge tube. Stage two is a pair of current limiting series resistors and the final stage is a low capacitance diode array. The RS-422/485 control line is connected to the protector via its screw terminal blocks. The terminal blocks are removable to ease wiring. The ALS-D25P12DW is designed to work with either 1 full duplex or 2 half duplex RS-422/485 lines.

12VDC Power Lines

The 12VDC power lines are also protected using a 3-stage design. This provides superior protection from transients and surges. The first stage is comprised of a differential gas discharge tube. Stage two is a pair of suppression coils and the final stage is a 5000 Watt uni-polar Transient Voltage Suppression (TVS) Diode. Power lines are connected to the protector via high current rated screw terminals.

Weatherproof Design

These units feature a weatherproof ABS enclosure with gasketed cover and concealed mounting holes. Water tight cable glands provide entry and exit points for cables. A ground clamp on the enclosure's exterior provides a tie point for earth ground.

For mounting to masts up to 2 inches in diameter, the HGX-PMT24 mast mounting kit is available (sold separately).

This protector is also available in the following power configurations:
12-28VAC: ALS-D25P1228AW

For additional information and complete specifications, click on the data sheet link below.


  • Individual protection circuits for RS-422/485 control lines and 12VDC power lines
  • 3-Stage protection provided for all lines
  • Will work with Full or Half Duplex RS-422/485 lines
  • NEMA rated enclosure with gasketed cover and concealed mounting holes
  • Also available in 15VDC, 24VDC and 12-28VAC versions