UL 506:2008 pdf download.Specialty Transformers.
3 Glossary
3.1 For the purpose of this standard,the following definitions apply.
3.2 COMPOUND-FILLED TRANSFORMER - A transformer in which the windings are enclosed withan insulating fluid that becomes solid, or remains plastic, at intended operating temperatures.
3.3 ENCAPSULATED COIL - A coil that is enclosed with an insulating fluid that becomes solid.3.4 EXPOSED CORE TRANSFORMER - A transformer with exposed core lamination.
3.5 NONVENTILATED DRY-TYPE TRANSFORMER - A dry-type transformer other than of thecompound-filled or exposed core-type that is constructed so as to provide no intentional circulation ofambient air through the transformer and is intended to operate at normal ambient room air pressure.
3.6 VENTILATED DRY-TYPE TRANSFORMER - A dry-type transformer that is constructed so thatambient air may circulate through the enclosure to cool the transformer core and windings.
3.7 WINDING - A continuous conductor made up of a number of turns magnetically coupled to amagnetic core, to which a voltage is either applied or induced.Two or more such conductors that arepermanently factory connecled together to form intermediate voltage taps, current taps, or the like areconsidered to be a single winding.The winding can consist of single or parallel-wound conductors.ALL TRANSFORMERS
CONSTRUCTION
4 Mechanical Assembly
4.1 A transformer shall be formed and assembled so that it will have the strength and rigidity necessaryto resist the abuses to which it is likely to be subjected. A risk of fire,electric shock, or injury to personsshall not result from a reduction of spacings, loosening or displacement of parts,or other serious defectdue to total or partial collapse of the transformer.
