UNDERWRITER'S Laboratories has added humidity-conditioning requirements for commercial electric cooking appliances.
The UL 499 standard is acceptable for UL 197 recognition. The ninth edition of UL Standard 197 Commercial Electric Cooking Appliances includes a new requirement for a three-day humidity conditioning for appliances that have one or more sheathed heating elements. This conditioning must be completed prior to performing the leakage current test on the appliance. The requirement becomes effective on March 26, 2007 and is defined in paragraph 46.8.
There are two exceptions to this requirement. The first states the entire appliance does not need to be conditioned if the elements are removable. The elements alone may be conditioned and then re-installed in the appliance prior to the leakage current test. The second exception states, "The conditioning is not required if all of the sheathed heating elements in the appliance comply with the requirements of the resistance to moisture test of UL 1030."
With approved end seals, this conditioning process does not need to be performed on existing Watrod, Firebar and Multicoil heating elements because the elements are recognised under UL 499 and comply with the UL 1030 resistance to moisture test.