Equipment, wiring methods, and installations of equipment in hazardous locations must be intrinsically safe, or approved for the hazardous location, or safe for the hazardous location. Requirements for each of these options are as follows:
(1) Equipment and associated wiring approved as intrinsically safe are permitted in any hazardous location for which it is approved.
(2) Requirements to be approved for the hazardous location:
(a) Equipment must be approved for the class of location and for the ignitable or combustible properties of the specific gas, vapor, dust, or fiber that will be present.
(b) Equipment must be marked to show the class, group, and operating temperature or temperature range, based on operation in a 40 degrees C (104 degrees Fahrenheit) ambient, for which it is approved. The temperature marking must be a maximum of the ignition temperature of the specific gas or vapor to be encountered. The following provisions apply to specific equipment:
(i) Nonheat-producing equipment, such as junction boxes, conduit, and fittings, and heat-producing equipment with a maximum temperature of 100 degrees C (212 degrees Fahrenheit) need not have a marked operating temperature or temperature range.
(ii) Fixed lighting fixtures marked for use in Class I, Division 2 locations only, need not be marked to indicate the group.
(iii) Fixed general-purpose equipment in Class I locations (other than lighting fixtures) that is acceptable for use in Class I, Division 2 locations need not be marked with the class, group, division, or operating temperature.
(iv) Fixed dust-tight equipment (other than lighting fixtures) that is acceptable for use in Class II, Division 2 and Class III locations need not be marked with the class, group, division, or operating temperature.
(3) Equipment that is safe for the location must be of a type and design that provides protection from the hazards arising from combustible and flammable vapors, liquids, gases, dusts, or fibers.
Note: | Equipment that meets the requirements of The National Electrical Code, NFPA 70, shall be considered in compliance with the requirements of WAC 296-307-372. |
[Statutory Authority: RCW
49.17.010,
49.17.040,
49.17.050, and
49.17.060. WSR 20-21-091, § 296-307-37209, filed 10/20/20, effective 11/20/20. Statutory Authority: RCW
49.17.040. WSR 98-24-096, § 296-307-37209, filed 12/1/98, effective 3/1/99. WSR 97-09-013, recodified as § 296-307-37209, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW
49.17.040, [49.17.]050 and [49.17.]060. WSR 96-22-048, § 296-306A-37209, filed 10/31/96, effective 12/1/96.]