UL 506:2022 PDF Download

UL 506:2022 is a standard that covers specialty transformers, specifically ignition transformers for use with gas burners and oil burners, as well as specialty step-up transformers used in applications such as insect electrocuting. The standard also applies to transformers that incorporate overcurrent or over-temperature protective devices, transient voltage surge protectors, or power factor correction capacitors. These transformers are intended for use in accordance with the National Electrical Code, NFPA 70.

However, the UL 506:2022 standard does not cover liquid-immersed transformers, variable voltage autotransformers, transformers with a primary rating over 600 volts, transformers with overvoltage taps rated over 660 volts, cord and plug connected transformers, garden light transformers, voltage regulators, swimming pool and spa transformers, or other special types of transformers that are covered under requirements for other electrical devices or appliances.

Additionally, the standard explicitly states that it does not cover autotransformers used in industrial control equipment (which are evaluated under UL 508), Class 2 or Class 3 transformers (evaluated under UL 5085-1 and UL 5085-3), toy transformers (evaluated under UL 697), transformers for use with radio- and television-type appliances (evaluated under UL 1411), transformers for use with high-intensity discharge lamps (evaluated under UL 1029), transformers for use with fluorescent lamps (evaluated under UL 935), ventilated transformers for general use or non-ventilated transformers for general use (evaluated under UL 1561), dry-type distribution transformers rated over 600 volts (evaluated under UL 1562), transformers incorporating rectifying or waveshaping circuitry (evaluated under UL 1012), transformers of the direct plug-in type (evaluated under UL 1310), transformers for use with electric discharge and neon tubing (evaluated under UL 2161), and general purpose and industrial control transformers (evaluated under UL 5085-1 and UL 5085-2).