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那看这一段标准上的列子IEC61131-2
! e' v7 S5 A& fZone 1: At the field wiring terminals the 1,6 mm from Table 51 dominates the 1,64 mm, g3 T4 G# g# W' Q2 p7 t
creepage distance from Table 54. Therefore, a minimum of 1,6 mm clearance and creepage
4 I7 ]6 v: I% Y7 d+ n" d" Gdistance shall be maintained. Beyond field wiring terminals, basic clearances shall be 1,50
0 b0 m" f k% \+ v9 cmm or greater, according to Table 49, and creepage distances shall be 1,64 mm or greater,- h) L2 l. l: o
according to Table 54.
I T6 s6 V- J/ ^9 AZone 2: On a printed circuit board a minimum basic clearance of 2,25 mm shall be maintained
6 w$ k9 k4 B4 L$ F/ Z$ u: haccording to Table 49 for the working voltage of 450 V and a creepage of 2,85 mm from+ M( Y; |/ q; `* J; H: }4 ?
Table 56 because of the 1 600 V recurring peak。$ r2 |4 s3 S4 Z' e" ]
At the isolation boundary to the SELV circuit the 2,3 mm clearance from Table 50 dominates
6 i: N& u4 u, zthe 1,73 mm creepage calculated by multiplying the interpolated value of 0,87 from Table 553 y. [4 R5 P5 q* W* H. S, d
by 2 according to 11.4.4 for double insulation. Therefore, a 2,3 mm minimum clearance and
9 V) k1 @$ M H7 dcreepage distance shall be maintained.
2 j& d3 x) x1 e( K, `最后在取SELV的爬电距离时,选择了系统电压值。 |
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