28.1 Resistance to abnormal heat and to fire 耐異常溫度和耐燃
Parts of insulating material which might be exposed to thermal stresses due to electric effects, and the deterioration of which might impair the safety of the accessory, shall not be unduly affected by abnormal heat and by fire.
Compliance is checked by the test of 28.1.1 and, in addition, for plugs with pins provided with insulating sleeves, by the test of 28.1.2
檢驗︰做 28.1.1 條的試驗，此外對於帶絕緣套插銷的插頭做 28.1.2 條的試驗。
28.1.1 Glow-wire test 灼熱絲試驗
The test is performed according to IEC 60695-2-10 and IEC 60695-2-11 under the following conditions:
按 IEC 60695-2-10 及 IEC 60695-2-11 在如下條件下做試驗︰
− for parts made of insulating material, necessary to retain current-carrying parts and parts of the earthing circuit of fixed accessories in position, by the test made at 850 ℃ with the exception of parts of insulating material needed to retain the earth terminal in position in a box, which shall be tested at a temperature of 650 ℃
− for parts of insulating material, not necessary to retain current-carrying parts and parts of the earthing circuit in position, even though they are in contact with them, by the test made at a temperature of 650 . ℃
If the tests specified have to be made at more than one place on the same specimen, care shall be taken to ensure that any deterioration caused by previous tests does not affect the result of the test to be made.
Small parts, where each surface lies completely within a circle of 15 mm diameter, or where any part of the surface lies outside a 15 mm diameter circle and where it is not possible to fit a circle of 8 mm diameter on any of the surfaces, are not subjected to the test of this subclause (see figure 39 for diagrammatic representation).
NOTE 2 When checking a surface, projections on the surfaces and holes which are not greater than 2 mm on the largest dimension are disregarded.
注 2︰對表面進行檢驗時，表面的凸起和最大尺寸不超過 2mm的孔洞忽略不計。
The tests are not made on parts of ceramic material.
NOTE 3 The glow-wire test is applied to ensure that an electrically heated test wire under defined test conditions does not cause ignition of insulating parts or to ensure that a part of insulating material, which might be ignited by the heated test wire under defined conditions, has a limited time to burn without spreading fire by flame or burning parts or droplets falling down from the tested parts onto the pinewood board covered with a tissue paper.
If possible, the specimen should be a complete accessory.
NOTE 4 If the test cannot be made on a complete accessory, a suitable part may be cut from it for the purpose of the test.
The test is made on one specimen.
The test is made applying the glow-wire once.
In case of doubt, the test shall be repeated on two further specimens.
The specimen shall be positioned during the test in the most unfavourable position of its intended use (with the surface tested in a vertical position).
The tip of the glow-wire shall be applied to the specified surface of the specimen taking into account the conditions of the intended use under which a heated or glowing element may
come into contact with the specimen.
The specimen is regarded as having passed the glow-wire test if
− there is no visible flame and no sustained glowing, or if
− flames and glowing at the specimen extinguish within 30 s after removal of the glow-wire.
在灼熱絲移去後 30 s 內，試樣上的火焰熄滅或輝光消失.
There shall be no ignition of the tissue paper or scorching of the board.
28.1.2 The specimen of a plug with pins provided with insulating sleeves is tested by means of the test apparatus as shown in figure 40.
對於插銷有絕緣套的插頭，應按圖 40 所示的裝置做試驗。
This test apparatus consists of an insulating plate A and of a metal part B: between these two parts an air space of 3 mm shall be provided and this distance shall be obtained through means which do not impair the air circulation around the pins.
試驗裝置由絕緣板 A 和金屬塊 B 組成，這兩個部件之間必須有 3mm的間隙，該間
The front surface of the insulating plate A shall be round and flat and have a diameter equal to twice the maximum permissible dimension of the engagement face of the plug given in the relevant standard sheet.
The thickness of this insulating plate shall be 5 mm.
The metal part B shall be of brass and have, for a distance of at least 20 mm, the same shape as the maximum outline of the plug according to the relevant standard sheet.
金屬塊 B應由黃銅製成，它必須具有至少 20mm長、形狀與適用標準規定的插頭的最大輪廓相同的部分。
The rest of this metal part shall be so shaped that the accessory under test is heated through it by conduction, and the heat transmission to the accessory under test by convection or radiation is reduced to a minimum.
A thermocouple shall be inserted at a distance of 7 mm from the front surface of the metal part in a symmetrical position, as shown in figure 40.
將一個熱電偶對稱地放在距金屬塊正面 7mm之處，如圖 40 所示。
The dimensions of the holes for the pins in the metal part B shall be 0,1 mm larger than the maximum dimensions of the pins given in the relevant standard sheet and the distances between the pins shall be the same as those given in the relevant standard sheet; the depth of the holes shall be sufficient.
NOTE 1 The metal part B can be made of two or more component pieces, for hole cleaning purposes.
The specimens are inserted in the test apparatus, placed in the most unfavourable horizontal position, when the test apparatus has reached a steady temperature, measured by means of the thermocouple, of (120 ± 5) for accessories having a rated current of ℃ 2,5 A, and (180 ± 5) for ℃ accessories having a higher current rating.
試驗裝置上。對於額定電流為 2.5A 的插接裝置，試驗溫度為 120±5℃，對於更高額
The temperature is maintained at the relevant values for 3 h.
溫度應保持 3 小時。
The specimens are then taken out from the test apparatus and are allowed to cool down to room temperature, at which they are maintained for at least 4 h.
然後從試驗裝置上拆下試樣並讓它暴露在室溫下至少 4 小時冷卻至室溫。
The insulating sleeves of the pins of the specimens are then submitted to an impact test in accordance with clause 30 but made at ambient temperature, and subject to visual inspection.
然後使試樣插銷的絕緣套在室溫下經受第 30 章的衝擊試驗。之後進行外觀檢查。
NOTE 2 During visual inspection, no cracks on the insulating sleeves should be visible with normal or corrected vision without additional magnification, and the dimensions of the insulating sleeves should not have changed so as to impair protection against accidental contact.