UL and ETL are both what is called Nationally Recognized Testing Laboratories (NRTL). NRTL’s are in place to provide independent safety and quality certifications on products, for electrical appliances their certification is typically required (especially 240V appliances). UL develops the testing standards and tests to them, ETL tests to UL standards. In order for an inspector to sign off on permitted installation for an EVSE the National Electric Code requires that the EVSE be NRTL listed (in the US that is ETL or UL). ClipperCreek does use both laboratories; the selection of which laboratory depends on which company provides the best value for their service that we can then in turn pass on to our customers.
Learn more about safety certification in our video: Charging Station Buyer's Guide: Staying Safe