UL now offers iQ for Surge-Protective Devices, a free online database that gives you the ability to find, verify and specify a Surge Protective Device by selecting from a set of over 20 parameters to meet your specific application. Watch the video to learn how UL iQ can help you find the SPD you are looking for.



Surge Protective Devices (SPDs), intended to afford protection from electrical surges and spikes, including those caused directly and indirectly by lightning, are utilized as both complete devices and as components within electrical equipment installed in AC and DC power applications.

With combined testing of SPDs, UL can simultaneously provide global market access solutions for the UL Mark in North America, as well as other certifications for markets around the world. One certification process allows you to profit from faster speed to market. This streamlined and accelerated process saves time and money through a well-proven global certification program:

  • U.S. – UL 1449
  • Canada – CSA C22.2 NO. 269.1-5
  • International – EN/IEC 61643 series

Permanently connected, photovoltaic (PV), DC, receptacle, molded case, circuit breaker and open-type SPDs intended for installation in accordance with Article 285 of NFPA 70 (National Fire Protection Association – National Electrical Code) are investigated as Type 1, 2 and 3 SPDs. Cord connected and direct plug-in SPDs, intended to be directly plugged into a permanently installed branch circuit receptacle outlet (such as a wall outlet), are investigated as Type 3 SPDs.

Discrete component SPDs (such as metal oxide varistors, gas discharge tubes and silicon avalanche diodes) and component assemblies, intended for factory installation in end products or equipment where the use is evaluated by UL, are investigated as Types 1, 2, 3, 4 Component Assemblies and Type 5 component SPDs.

The use of SPDs is often specified by the end user or mandated by code or local requirements. For example, NFPA 780 and UL 96A (Standard for Installation Requirements for Lightning Protection Systems) require the use of surge protection as an integral part of a lightning protection system. Additionally, NFPA Article 708 requires surge protection to be installed at all facility distribution levels in Critical Operations Power Systems (COPS).

UL’s proven expertise in safety science and engineering enables us to serve the entire SPD industry, from simple SPDs for light commercial and residential applications to complex SPDs that monitor and record the number of surges and indicate the status of an SPD. Our extensive, flexible service portfolio covers all of our customers’ core business needs, such as research and development, global market access, installation and end use.

View the scope and table of contents for the UL Standard that applies to your regulatory or engineering needs.