UL 5085-2-2021 pdf free download.Low Voltage Transformers – Part 2: General Purpose Transformers.
8.5.10 When a transformer is not intended for outlet box mounting and is not provided with a terminal orwinding compartment, the leads shall enter the enclosure either through a nipple or other means for theattachment of rigid metal conduit. Alternatively, the leads shall enter through separate holes that provide aspacing of not less than 6.4 mm (0.25 inch) between the conductors and not less than 12.7 mm (0.5 inch)between the conductors and the plane of the transformer support.
8.5.11Transformers, and their external leads, intended for installation in other enclosures (e.g., controlcircuit transformers housed with industrial control equipment) may have:
a) Primary and secondary leads in the same opening,when they have insulation suitable for thehighest voltage involved and a temperature rating of at least 105 °℃(221 °F)and
b) Metal grommets or smooth, folded edges.
8.5.12 One of the secondary terminals or leads of an autotransformer intended for operation on a circuitof 150 V or less to ground shall be identified for the connection of a grounded circuit conductor. It shall bedirectly connected to a similarly identified primary terminal or lead.The identification shall be as specifiedin Clause 17.5.1.
8.6Splice compartment
8.6.1 When a transformer is provided with leads to which field conductors will be spliced, the leads shallbe located in a space providing a usable volume in compliance with Table 1.
8.7Wiring compartment
8.7.1 A wiring-compartment intended for field connections shall be free of sharp edges, burrs, fins, ormoveable parts that can damage conductor insulation.
8.7.2 There shall be enough wiring space to accommodate connections to the transformer as specified inClauses 8.8.1-8.8.6.When the transformer is marked for additional uses that require more wiring space,the additional space may be provided by a field-added wiring space extension assembly. Examples ofadditional uses are:
a)Use of two or more single-phase transformers to make up a multi-phase transformer bank;b)Connection of a two-winding transformer as an autotransformer; and
c) Connection of a transformer for buck or boost use.
The wiring space extension assembly shall comply with the requirements in Enclosures in Clause 6 of Part1, and shall be marked as specified in Clauses 17.5.11 and 17.5.12.
8.8Wire bending space
8.8.1 A wiring space shall be clear of all obstructions and have a cross-sectional area not less than 250percent of the total cross-sectional area of the maximum number of wires intended for installation in thewiring space.The minimum width or depth shall not be less than that shown in Table 2.UL 5085-2 pdf download.