What are the UL enclosure types?
A. Underwriters Laboratories adopted a system for rating transformer enclosures which differs somewhat from the NEMA system. The UL system lists just three enclosure types. A UL Type 1 enclosure is intended for indoor service and offers a degree of protection from contact with the device inside the enclosure. UL Type 2 enclosures are also intended for indoor service and provide protection of the equipment inside the enclosure from limited amounts of falling dirt and water. UL Type 3R enclosures can be used either indoors or outdoors and provide protection against rain, sleet, snow and ice formation. The proper UL enclosure rating is listed on the transformer nameplate.
Underwriters Laboratories adopted a system for rating transformer enclosures which differs somewhat from the NEMA system. The UL system lists just three enclosure types. A UL Type 1 enclosure is intended for indoor service and offers a degree of protection from contact with the device inside the enclosure. UL Type 2 enclosures are also intended for indoor service and provide protection of the equipment inside the enclosure from limited amounts of falling dirt and water. UL Type 3R enclosures can be used either indoors or outdoors and provide protection against rain, sleet, snow and ice formation. The proper UL enclosure rating is listed on the transformer nameplate.
