ProTec DMDR 20

When Class I and Class II SPDs are not enough to protect sensitive electronic elements, Class III elements stop additional overvoltage waves. The incidence of low-value surges may still be too high for electronic elements and are common in the object itself, often caused by activation switching of major appliances, inductive devices, and motors, or industrial system operation failures. SPDs in the IEC Class III / EN Type 3 classification are intended to protect sensitive electronic installations in Zones 2-3 per IEC 62305.


  • IEC Class III/EN Type 3 SPDs
  • Hybrid design consisting of high-performance varistors for each pole and a high energy encapsulated gas discharge tube (GDT) with separate thermal disconnect mechanisms
  • Pluggable module design facilitates the replacement of a failed module in place, without the need to remove system wiring