With over 300 million electric motors being used globally, and 30 million new electric motors being sold each year for industrial purposes alone[1] – manufacturers of adjustable speed drives (ASDs) for electric motors have abundant opportunities in the global market. The ASD’s ability to help achieve efficiencies and improve control of the motor drive system explains the growing demand for these products.

Navigating complex and varying safety requirements for ASDs, however, can pose challenges to global market access. Until 2016, manufacturers wanting to access the United States, Europe, and other markets had to have their products comply with at least two very different standards – UL 508C – Power Conversion Equipment and IEC 61800 – Adjustable Speed Electrical Power Drive Systems, Part 5-1: Safety Requirements – Electrical, Thermal, and Energy.

The new, harmonized UL 61800-5-1 replaces the former standard and incorporates many of the requirements from the IEC standard, with some national deviations. This means that manufacturers can rely on one source for all compliance testing and certifications for ASDs, globally. But while harmonization helps enable faster global market access, the sheer number of changes in the new standard need to be understood by manufacturers to help ensure a smooth transition and achieve compliance to successfully bring products to market.

With many of our customers – and others in the industry – impacted by the new standard, CSA Group breaks down the requirements and highlights key dates to help you get on the right track.

What’s changed?

The following clauses in the new standard contain the most significant changes:

4.3.6 Insulation Requirements (Clearance and Creepage)

  • There are five definitions for insulation, which will determine the evaluation for protection requirements. Two means of protection are also required against direct contact.
  • UL840 is no longer an applicable standard for clearances and creepages investigation.
  • Where protective separation is required:
    • clearance and creepage requirements are greater than those required by UL 840 and UL 508C; and
    • impulse test for reduced clearances is not allowed.
  • Where functional insulation is needed, the required clearances may be smaller.
  • Surge protective devices (SPDs) cannot be used to reduce the overvoltage category for protective separation.
  • Using SPDs to reduce the required clearances is only allowed for basic and functional insulation. These devices are required to be monitoried and an indication of their status is also needed.
  • Investigation of clearances and creepages is required on inner layers of printed wiring boards (PWBs). Alternatviely, the inner layers can be investigated to solid insulation requirements. Short Circuit and Breakdown of Components Test

  • All power outputs – not just the motor ouput – must be short circuit tested.
  • Cotton indicator is required for all short circuit tests.
  • Set up for the breakdown components test are the same as the short circuit test.
  • The circuit used for the breakdown of components test must be capable of standard and high fault currents based on manufacturer’s short circuit current rating, unless detailed analysis shows a different value is equivalent or more severe.
  • During all tests, voltages of secondary circuits must be monitored and not exceed certain levels, or the AC/DC voltage test must be conducted afterwards. Protective Bonding Test

  • Products with accessible conductive parts are required to comply with the protective bonding test.

How these changes impact you

As the changes are significant, a product certified to UL 508C will not automatically comply with the new standard. The need for a change in your design to ensure compliance is likely.

To support a more seamless transition, products previously certified to UL 508C may remain certified even after the standard is withdrawn, so long as the product is not modified afterwards. Should modifications be made to the product’s design, then an investigation will need to be conducted to verify that the product complies with the new standard.

In addition, just like products evaluated to the UL 508C standard, products investigated to UL 61800-5-1 are to be installed according to the requirements specified in NFPA 70 (NEC). There will be no changes to category control numbers or product identify markings. As a result, the transition is not expected to create field issues regarding acceptance of products evaluated to the harmonized standards.

The transition to the new standard applies to products being certified for the U.S. market. CSA C22.2 No. 286 is the standard for investigation for use in Canada – an important consideration if you’re selling your product to both Canada and the U.S.

Key dates to know


All new products are required to be certified to the new standard. This includes any model not previously certified to UL 508C, or any new model in an existing series currently certified to UL508C that requires an associated change to the ratings or production construction details of the certifier’s report for that series.

July 2, 2020

Only UL 61800-5-1 will be used for ASDs certified to U.S. standards at CSA Group. Some other testing & certification providers have an implementation date of February 1, 2020.

To prepare for the standard’s full implementation, manufacturers should begin communications with their testing & certification provider at least one year before UL 508C is withdrawn. This time is needed to update the certification and conduct additional testing, if required.

Guiding you through the transition

CSA Group’s robust portfolio of services for the industrial sector provides manufacturers with trusted experts and safety marks for products used in the new digital age. We have one of the largest teams of highly experienced industrial professionals who help you meet your timeline to market, and our commitment to quick project turnaround contributes to significant time and cost savings for our customers. We keep pace with rapidly changing technology and consider the associated safety concerns as they arise, such as this standard. And above all else, we know that behind your success is a commitment to protecting your customer’s lives while powering industry.

CSA Group is fully equipped to certify your product to both the CSA standard for Canada and the new UL standard for the U.S. market.

Contact us today to learn how we can help you in the transition to UL 61800-5-1.

[1] The Institute for Industrial Productivity, “Motor Systems,” Industrial Efficiency Technology Database. Retrieved from http://ietd.iipnetwork.org/content/motor-systems.