1、Introduction and ReasonClause 22.14 of IEC 60335-1 requires “Appliances shall have no ragged or sharp edges, other than those necessary for the

functioning of the appliance, which could create a hazard for the user in normal use or during user maintenance.”and“Compliance is

checked by inspection”.But inspection is subjective，which results in inferior repeatable of judgment results due to different sensory in

sharpness of testers.We have received feedbacks from some manufacturers ,which products were judged ”failure” just because of "looks sharp" in

optical of the test engineer .But in fact, these "sharp edges" will not cause harm to human body. To estimate these edges sharp for person or not, we suggest manufacturers to test according to the requirements of IEC / TR 62854 (UL 1439).

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October 2019

At the same time, there is a certain cut risk for the tester. Because the standard requirement is "inspection", some test engineers may touch these edges with their fingers to judge it sharp or not . When those edges are really sharp, they may cause harm to testers.

In order to eliminate the difference of test results between different laboratories and different testers, and avoid the risk of testers being cut by edge test, it is suggested to replace the requirement of edge test in IEC 60335-2-31, which is based on IEC / TR 62854 (UL 1439). We choose 20 testers (male and female) to test the same edge respectively. Due to the difference (optical, strength, time, etc) of the person ,the results are different. However, following the test requirements of IEC / TR 62854 (UL 1439), the results can be repeatable.

Exploded Views for a Range Hood

sharp edges samples for a rang hood：

Sample 1：Drawing panel , the person may touch these parts while installing .

Sample 2：Check valve , the person may touch these parts while installing.

Sample 3：Protective screening , the person may touch these parts while cleaning.

Sample 4：Oil cup (metal), the person may touch these parts while cleaning.

Sharp edge tester with tape cap, according to TR 62854/ UL 1439

Tester No /Gender

Sample No1 2 3 4

inspectionTR

62854 inspectionTR

62854 inspectionTR

62854 inspectionTR

628541(M) x √ √ √ √ √ x x2(F) x √ √ √ x √ x x3(F) √ √ √ √ √ √ √ x4(M) √ √ √ √ √ √ x x5(M) √ √ x √ √ √ x x6(F) √ √ √ √ √ √ x x7(M) √ √ √ √ √ √ x x8(M) √ √ √ √ √ √ x x9(M) √ √ √ √ √ √ x x10(F) x √ x √ x √ x x11(M) √ √ √ √ √ √ x x12(M) √ √ √ √ √ √ √ x13(F) √ √ √ √ √ √ x x14(M) x √ x √ √ √ x x15(M) √ √ √ √ √ √ x x16(F) √ √ x √ √ √ √ x17(M) √ √ √ √ √ √ x x18(M) √ √ √ √ x √ x x19(M) √ √ √ √ √ √ √ x20(M) x √ √ √ √ √ x x

Sample 1: Pass Sample 2: Pass Sample 3: Pass Sample 4: Failure

Conclusion：Test method in TR 62854 is more repeatable than Inspection，and is necessary.

2、Why just for Range Hood，not for All Appliance？Compared to other appliances, the structure of range hoods have many long metal edges. Users must clean the edges frequently.

The edges may create a hazard for user in normal use or during user maintenance. There are a large number of accessible metal parts in the range hood . Although these accessible metal parts are very thin(0.5mm to 2mm),their edges are not enough "sharp" to hurt person because of special processing.

No similar problems have been reported frequently with other appliances on the market. We have not assessed the impact of this proposal on other appliances. So we suggested only modifying IEC 60335-2-31 at present.

In the future, if more and more other appliances follow this proposal, we will propose it to part 1.

3、Proposal （Revised）2 Normative referencesAdd a new reference:IEC TR 62854:2014 Sharp edge testing apparatus and test procedure for lighting equipment. Tests for sharpness of edge.22.14 Replacement:Compliance is checked by inspection. In case of doubt the test described in cl. 2 and 5 of IEC TR 62854 shall be carried out on

edges. After the test, the outermost two sensing layer of the tape-covered head shall not to be penetrated.