UL 921-2016 pdf free download

UL 921-2016 pdf free download.Commercial Dishwashers.
4.10.1 Conductors of circuits operating at different potentials shall be reliably separated from each other unless each conductor is provided with insulation rated for the highest potential involved in the circuits.
4.10.2 An insulated conductor shall be retained so that it does not contact an uninsulated live part of a circuit operating at a different potential.
4.10.3 In a compartment intended for the field installation of conductors, and that contains provision for connection of Class 2 circuit conductors, and Class 1 power or lighting circuit conductors, a barrier shall be provided to separate the conductors of the different circuits, or the arrangement of the compartment shall be such that a minimum spacing of 6,4 mm (1/4 in) is maintained between all circuit conductors located in the compartment.
4.11 Insulating materials
4.11.1 An insulating washer, a bushing, or similar component, and a base or a support for the mounting of current-carrying parts shall be of a moisture-resistant material, such as porcelain, phenolic, or cold-molded composition, or other material that is rated for the application, and shall not be adversely affected by the temperatures to which it is subjected under conditions of intended use.
4.11.2 The effects of the following factors on insulating material in conjunction with the effects of thermal aging on the insulating material shall be determined for compliance with 4.11.1:
a) mechanical strength:
b) dielectric strength:
C) insulation resistance;
d) the degree to which the material is enclosed or protected: and
e) any other factor that has a bearing on the risk of fire, electric shock, and injury to persons, under conditions of intended use.
4.11.3 Materials such as mica, some molded compounds, and certain refractory materials are typically usable as the only support of a current-carrying part. A material, such as magnesium oxide, shall not be used for direct contact or support of current-carrying parts unless the material is used in conjunction with other insulating materials or is so located and protected so that the current-carrying parts are not damaged and the material does not absorb moisture.
4.11.4 A thermoplastic or thermosetting material shall not be used for the direct contact or support of uninsulated current-carrying parts unless the material is rated with respect to mechanical strength and rigidity, resistance to heat, resistance to flame propagation, resistance to electrical arcing, dielectric strength, and other properties for the condition of use.UL 921-2016 pdf free download.