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19.5 The test of 19.4 is repeated on class 0I appliances and class I appliances
' s9 b7 |. N" r* J: O& fincorporating tubular sheathed or embedded heating elements. However, controls are not
- G+ P3 ]; G& g- o* oshort-circuited but one end of the element is connected to the sheath of the heating element.
6 V9 m7 V4 p; fThis test is repeated with the polarity of the supply to the appliance reversed and with the 5 z% o9 |% H9 D a4 h, J6 F
other end of the element connected to the sheath.
" u6 D, Q( s, i' Q, ]The test is not carried out on appliances intended to be permanently connected to fixed wiring 6 H8 G( a+ u3 N2 V. j, Q+ t
and on appliances where an all-pole disconnection occurs during the test of 19.4.
1 l: |! J! o4 @( a: d7 J; KAppliances with a neutral are tested with the neutral connected to the sheath. 2 A9 }' M! K5 t) h
NOTE For embedded heating elements, the metal enclosure is considered to be the sheath.
' T5 W& ^+ D/ Z0 E4 ]# c9 X" s什么意思三相三线的取暖器需要测试吗
) Y8 A7 ^# T6 C$ X% D怎么测试3 X; o* B+ H7 c" U
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