Many organizations have established standards that address uninterruptible power supply safety, performance, testing, and maintenance.

Standards are norms or requirements that establish a basis for the common understanding and judgment of materials, products, and processes. Standards are an invaluable tool in industry and business, because they streamline business practices and provide a level playing field for businesses to develop products and services. They are also critical to ensuring that products and services are safe for consumers and the environment.

Below are uninterruptible power supply (UPS) safety and compatibility requirements for both general and medical environments.

International Electrotechnical Commission (IEC)


  • IEC 62040-1:2017 EXV : Uninterruptible Power Systems (UPS) - Part 1: Safety requirements
  • IEC 62040-2:2016 : Uninterruptible Power Systems (UPS) - Part 2: Electromagnetic compatibility (EMC) requirements
  • IEC 62040-3: Uninterruptible Power Systems (UPS) - Part 3: Method of specifying the performance and test requirements – Uninterruptible Power Supplies

Underwriters Laboratories (UL)


UPS output waveform compared to normal 120 VAC 60 Hz power waveform
This image shows the non-sinusoidal nature of the AC power provided by some inexpensive consumer grade uninterruptible power supplies (in this case APC model "Back-UPS 550"). The UPS output is shown in yellow compared with a standard 120 VAC 60 Hz single phase waveform. This are actual waveforms measured by a dual trace digital oscilloscope.
Timothy Quill (CC BY-SA 4.0)