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隔离变压器的二次端绕组间的电压是大于selv的限值的,那么这段电路是接地或者未接地的次级危险电压电路。如果次级危险电压电路与初级仅有基本绝缘的时候,才要求这个次级危险电压电路与SELV满足附加绝缘或者加强绝缘(不是满足基本绝缘!)。(见IEC/EN60950-1 table 2H note C)+ p( \, P r- ^) x
如果SELV电路由次级危险电压电路供电,只要这个次级危险电压电路与初级是加强或双重绝缘即可。
% y/ i- T8 r8 u+ e5 x8 @If an SELV CIRCUIT is derived from a HAZARDOUS VOLTAGE SECONDARY CIRCUIT, and the3 ` `) s& P4 r! X8 ~
HAZARDOUS VOLTAGE SECONDARY CIRCUIT is separated from the PRIMARY CIRCUIT by DOUBLE
! `4 p) @9 i8 KINSULATION or REINFORCED INSULATION, the SELV CIRCUIT shall remain within the limits given in
4 `2 ?% ] z& K# @$ U3 ?) ]2.2.3 under single fault conditions (see 1.4.14). |
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