As a specifier of mechanical systems, you are probably familiar with product safety testing and approval by Underwriter’s Laboratories’ Inc. (UL), Factory Mutual (FM), or other organizations for certain types of hvacr equipment. But are you aware that similar safety standards apply to the electrical systems and components that are used with mechanical equipment?
Other electrical testing agencies, such as ETL and MET Electrical Testing Co. are also recognized NRTLs. Since these organizations generally test products according to the applicable UL standards, our discussion will focus on those standards and terminology, but this is not intended as an endorsement of UL over any other testing agency.