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那看这一段标准上的列子IEC61131-26 t: \8 T" k8 X6 |8 A
Zone 1: At the field wiring terminals the 1,6 mm from Table 51 dominates the 1,64 mm
. m1 B" ^1 J7 W0 b; u8 i3 tcreepage distance from Table 54. Therefore, a minimum of 1,6 mm clearance and creepage6 {4 x, W7 S) ?- j: X7 n- O7 x
distance shall be maintained. Beyond field wiring terminals, basic clearances shall be 1,50+ T. Z1 H3 C3 ]6 ?
mm or greater, according to Table 49, and creepage distances shall be 1,64 mm or greater,5 e6 ~2 M5 `) ~: V, S* D
according to Table 54.
+ `2 Z2 h! s* t# v1 B5 F+ [4 AZone 2: On a printed circuit board a minimum basic clearance of 2,25 mm shall be maintained
) }8 ?8 o3 B/ Paccording to Table 49 for the working voltage of 450 V and a creepage of 2,85 mm from+ U/ M, I v7 K9 h; T
Table 56 because of the 1 600 V recurring peak。+ o3 i1 z0 Y& X& Q& ?( M
At the isolation boundary to the SELV circuit the 2,3 mm clearance from Table 50 dominates
% t+ [/ |8 n) b3 q" p$ x( ]- Vthe 1,73 mm creepage calculated by multiplying the interpolated value of 0,87 from Table 55( \6 Z3 J3 v P, U
by 2 according to 11.4.4 for double insulation. Therefore, a 2,3 mm minimum clearance and+ M7 L) Y$ q7 k$ P# F
creepage distance shall be maintained.
. Y1 d7 b: p% w* c6 F6 @最后在取SELV的爬电距离时,选择了系统电压值。 |
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