UL 998, 6th Edition, April 9, 2020 – UL Safety Standard for Humidifiers
UL test report processing process:
1. Project application – submit a UL report application to the inspection and supervision agency.
2. Data preparation – According to the standard requirements, the enterprise prepares the relevant certification documents.
3. Product testing – the company sends the samples to be tested to the laboratory for testing.
4. Preparation of reports – certified engineers prepare reports based on qualified test data.
5. Submit for review – the engineer will review the complete report.
6. Issuing a certificate – After the report is verified and correct, a UL test report will be issued .
1 1 Scope 1.1 1.1 These requirements include humidifiers rated at 600V or less and used in accordance with the rules of the National Electrical Code (NEC), /NFPA 70, and CSA C22. 1, "Canadian Electrical Code" (CEC) Part I. 1.2 1.2 These requirements include humidifiers for residential and commercial use. This includes humidifiers of centrifugal atomization type, evaporative media type, water injection type, steam type, etc. Humidifiers are intended for installation in rooms, on walls or ceilings, or for duct or ventilation system installations. 1.3 1.3 These requirements apply to equipment that includes electrical heating elements for heating air or water, or both. 1.4 1.4 These requirements do not apply to evaporative coolers also used for cooling. 1.5 1.5 These requirements do not apply to portable electrode-type products such as vaporizers covered by UL 499 and /CSA-C22. 2 No. 64. 2 2 Definitions 2.1 2.1
The following definitions apply to this standard. 2.2 2.2 Extra-low voltage circuits—circuits with a potential AC potential not exceeding 30 V (42.4 peak) and a power not exceeding 100 VA; or 30 V dc supplied by the main battery; or powered by a Class 2 transformer; or powered by a transformer and fixed impedance The combined power supply, as a unit, meets all the performance requirements of a class 2 transformer. A circuit is not considered an extra-low voltage circuit if it exceeds 30 V by connecting a resistor or impedance (or both) in series with the power circuit to limit voltage and current. 2.3 2.3 Circuits, Hazardous Voltages – Circuits with characteristics exceeding those of extra-low voltage circuits. 2.4 2.4 Combined Temperature Regulation and Temperature Limiting Thermostat – A thermostat whose function is to regulate temperature under normal use conditions and to prevent hazards that may result from abnormal operating conditions of the heater. 2.5 2.5 Enclosure – An enclosure that houses electrical components, live parts and/or moving parts. It can be an integral part of an assembly, a separate item, part of a final enclosure, or a final enclosure (for example, an external enclosure). 2.6 2.6 Heating Elements—Complete or partial assemblies of heating elements, electrically insulating material (e.g., refractory, mica), metal jackets, glass or quartz enclosures or panels, thermal insulation, and frames or adapters used to secure the assembly in the together and hold it in the heater; and the wire or terminal connections used by the mUayLoCr Moaypnyotrinicgluhdetbeolts Amndatute, or both. Rial – 2.7 2.7 Heating – The bimolecular resistance is heated by an electric current.Distributed without UL license
2.8 2.8 Humidifier—A device used to increase the relative humidity of the air.
2.9 2.9 Terminal Block – A wiring device that closes the splices between wires and provides a socket for connecting parts of equipment.
2.10 2.10 Portable Equipment—Equipment designed for use in a non-fixed location, receiving electrical current through a cord or cable and connecting plug.
2.11 2.11 Safety Circuits—Circuits including any control gear contacts integrated with or external to the equipment designed to prevent unsafe operation of the equipment due to grounding, opening, or shorting of circuit wiring, such as:
a) a) a device to prevent the motor from overheating due to overload (including locked rotor);
b) b) temperature limit switches, the failure of which could result in unsafe operation; or
c) c) A pressure limiting device in the system which, if not functioning properly, could result in an unsafe situation.
2.12 2.12 Temperature Limiting Thermostat – A thermostat that operates only under conditions that produce abnormal temperatures. A malfunction of this thermostat can be dangerous.
2.13 2.13 Temperature Adjusting Thermostat – A thermostat that adjusts temperature only under normal conditions of use. The failure of such a thermostat will not cause a hazard.
2.14 2.14 User Service – Any form of service that may be performed by persons other than those trained in product maintenance. Some examples include routine cleaning, filter replacement, and replacement of accessible fuses or lights.