UL 923-2020 pdf download – Microwave Cooking Appliances.
2.23 PRIMARY INTERLOCK – A designation for one of the oven door interlocks. The primary interlock is intended to de-energize the microwave generator upon opening the oven door, before microwave radiation emission exceeds the levels specified in 39.1.1. 2.24 PRIMARY CIRCUITS – – The wiring and components that are conductively connected to the branch circuit. 2.25 SAFETY CIRCUIT – Any primary or secondary circuit that is relied upon to reduce a risk of fire, electric shock, injury to persons, or excessive radiation (microwave or X-radiation) emission. An interlock circuit, for example, is considered to be a safety circuit. 2.26 SECONDARY CIRCUIT – A secondary circuit is one that is supplied from an isolated secondary winding of a transformer. 2.27 SECONDARY INTERLOCK – A designation for one of the oven door interlocks. The operation of the secondary interlock is intended to prevent microwave radiation emission from exceeding the level specified in 39.1.1 when the door is opened. 2.28 STIRRER – That feature of a microwave cooking appliance that serves to continuously change the standing wave pattern within the oven cavity. 2.29 UNDER-CABINET MOUNTED MICROWAVE OVENS – A microwave cooking appliance that is installed under a cabinet and over a non-heat producing surface.
Exception: Where these other functions are not required for the application and not identified as part of markings, instructions, or packaging for the appliance, the additional component standard(s) need not be applied. 4.4 With regard to a component being additionally investigated, reference to construction and performance requirements in another UL end product standard is suitable where that standard anticipates normal and abnormal use conditions consistent with the application of this end product standard. 5 Frame and Enclosure 5.1 A microwave cooking appliance shall be so formed and assembled that it will have the strength and rigidity necessary to resist the abuses that it is likely to be subjected, without increasing the risk of fire, electric shock, injury to persons, or exposure to radiation emission in excess of the limits specified in these requirements due to total or partial collapse with resulting reduction of spacings, loosening or displacement of parts, or other serious defects. 5.2 The enclosure of a microwave cooking appliance shall house all electrical parts, except a supply cord, that may cause a fire, electric shock, injury to persons, or exposure to radiation emission in excess of the limits specified in these requirements under any condition of use. No dependence shall be placed on adjacent walls or adjacent equipment to complete an enclosure. If a microwave cooking appliance is intended for permanent installation (intended for permanent connection to the power supply), the appliance shall be provided with means for mounting in the intended manner and shall be furnished with any necessary fttings, such as brackets, hangers, or sleeve.