UL 347 2016 pdf download – Medium-Voltage AC Contactors, Controllers, and Control Centers.
2.2 Special service conditions 2.2.1 Altitude Installation at altitudes above 1 000 m up to 3000 m is also recognized in this standard. Variations in the design will in some cases be required. For example, considerations should be made for temperature rise, insulation level, and mechanical parameters affected by lower ambient pressures. Manufacturers should be prepared to supply any de-rating factors to be applied to the normal service condition ratings and any necessary setting adjustments. NOTE: Special conditions are in some cases also necessary for some types of operating mechanisms. 2.2.2 Solar radiation If the effects of solar radiation are significant, the principles stated in Annex A, Item 1 1 , may be used for guidance. 2.2.3 Evaluations and exceptions Conditions that equipment will experience should be evaluated in terms of the manufacturer’s designated ratings and limitations. Service conditions that are outside the limits described in Clause 2.1 should be called to the controller manufacturer’s attention, since special construction or protection will in some cases be required. 3 Definitions NOTE: Definitions that correspond to definitions in the International Electrotechnical Vocabulary (IEV) (IEC 60050–441 ) have been so identified with their corresponding IEV designation. 3.1 General terms 3.1 .1 01 controller and controlgear: A controller consists of a contactor, overload protection, a manual externally operated disconnector, and a short-circuit protective device, mounted and wired in an enclosure specifically designed and dimensioned for its application, in which all tests are conducted, and which may also include a grounding function. An auxiliary compartment may be provided if necessary to complete the function of the controller. NOTE: “Controlgear” is a general term covering controllers and auxiliary equipment supplied with controller vertical sections and in medium-voltage control centers.
3.1 .201 medium-voltage: For this standard, ac voltage in the range of 1 501 V to 1 5kV (in Canada, 751 V to 1 5kV). NOTE: The applicable installation codes will in some cases refer to this voltage range as “high-voltage.” 3.1 .202 medium-voltage compartment: A compartment containing one or more medium-voltage components. 3.1 .203 low-voltage: For this standard, ac voltage in the range of 50 to 1 500 V (in Canada, 30 to 750 V). NOTE: The applicable installation codes refer to voltages above 600 Vrms (750 Vrms in Canada) as “high voltage”.