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60950-1中:
H j! [2 O* h, G2 @) M+ Y! MPollution degree 1 applies where there is no pollution or only dry, non-conductive pollution. the pollution has no influence.normally ,this is achieved by having components and subasssembilies adequately enclosed by enveloping or hermetic sealing so as to exclude dust and moistrue+ c; C; m# ~4 W2 F& N9 r" r4 m
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Pollution degree 2 applies where there is only non-conductive pollution that might temporatily become conductive due to occasional condensation. it is generally appropriate for equipment covered by the scope of this standard
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P: a( h2 E+ c BPollution degree 3 applies where a local environment within the equipment is subject to conductive pollution, or to dry non-conductive pollution that could become conductive due to expected condensation. |
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