|
60950-1中:( H+ a) R; ?: B# r6 S, I
Pollution 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
' h% i/ ?5 Y! W/ p0 ~. q. q+ L9 t) z% `2 x% F+ G; h
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* h" H, R8 @3 q% O2 e4 }& W. l
0 A+ a2 ?9 {1 Y6 ?" ~7 R/ 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. |
|