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Surge Protective Device Testing and Certification Services

Providing investigations, testing and certification services for surge protective devices.

Lightning strike


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

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, the Standard for Installation Requirements for Lightning Protection Systems, require the use of surge protection as an integral part of a lightning protection system. Additionally, the National Electric Code, NFPA 70, requires surge-protective devices (Article 285) to be installed:

  • Where disconnecting means have been designated as supplying an emergency system load in elevators, dumbwaiters, escalators, moving walks, platform lifts and stairway chairlifts
  • For critical operations data systems of information technology equipment
  • For industrial machinery with safety interlock circuits
  • In or on the fire pump controllers
  • In or on all emergency systems switchboards and panelboards
  • At all facility distribution voltage levels in critical operations power systems (COPS)

The use of SPDs have increased due to the proliferation of more complex electronics, LED lighting, photovoltaics and microprocessor controlled devices that are more susceptible to damage due to surges caused by lightning and switching disturbances. Surge protection needs within a building will vary depending on the surge withstand capability of the equipment being protected, level of protection desired, geography or location of the equipment, and the functional criticality of the equipment.


With combined testing of SPDs, wecan 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 helps save time and money through a well-provenglobal certification program.

Our 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 research and development, Global Market Access, installation and end use.


UL evaluates SPDs to the following standards for compliance and safety:

  • U.S. UL 1449 the Standard for Surge Protective Devices (SPDs)
  • Canada CSA C22.2 NO. 269 Series of SPD Standards
  • International IEC/EN 61643-11, -311, -321, -331, IEC 61643-31, IEC 61051

Increased surge testing capability in North America

We have invested in new surge testing equipment in our Melville, New York, facility. The new equipment includes an impulse current surge generator capable of superimposing a 60 kA In (8/20) nominal discharge current testing through a device under test. Additionally, the new testing equipment includes both AC and DC power supplies allowing for energized surge testing energized with up to 1000 V AC and 1500 V DC.

This increased testing capability will allow for local surge testing of most surge protective devices to applicable U.S., Canadian and IEC surge protective device standards, including AC, DC and PV SPDs. This increased capability will result in decreased testing times and more testing options, as well as allow customers to streamline all their surge testing with UL.

We provide investigations, testing and certification services for the following types of SPDs:

  • Permanently connected — Types 1, 2 and 3 SPDs 
  • Cord connected — Type 3 SPDs
  • Outdoor-use (RV) cord connected — Type 3 SPDs
  • Direct plug-in — Type 3 SPDs
  • Receptacle type — Type 3 SPDs
  • Open-type — Types 1, 2 and 3 SPDs
  • Molded case SPDs — Types 1 and 2 SPDs
  • SPDs certified for use in specified equipment — Types 1 and 2 SPDs
  • Circuit breakers/SPDs — Types 1 and 2 SPDs
  • Photovoltaic (PV) — Types 1, 2, and 4 component assembly and Type 5 component SPDs
  • DC SPDs — Types 1, 2, 3 and 4 component assembly and Type 5 component SPDs
  • Modular component SPDs — Types 1, 2, 3 and 4 component assembly and Type 5 component
  • Discrete component SPDs — Type 4 component assembly and Type 5 component, includes:
    • SPDs metal oxide varistors (MOVs)
    • Gas discharge tubes (GDTs)
    • Silicon avalanche diodes (SADs)/avalanche breakdown diodes (ABDs) 
    • Hybrid devices consisting of MOVs, GDT, SADs and/or other components
  • IEC/EN 61643-11 CB Certificate (IEC 61643-11), Informative Test Report (CE), Test Type Certificates, UL EU Mark, D Mark, UL certification to IEC publications (VZCC)
  • IEC 61643-31  Informative Test Report (CE)
  • IEC/EN 61643-311, -321, -331 Informative Test Report (CE), Test Type Certificates, UL EU Mark, D Mark, UL certification to IEC publications (VZCC)
  • IEC 61051 Informative Test Report (CE), UL certification of component varistors to IEC Standards (YURA2)
  • Increased surge testing capability — New surge generator (Q1, 2019) – 60 kA In (8/20) while energized with AC (1000 V) or DC (1500 V)

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