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1)1.4.9 Measurement of voltage to earth
/ g) [$ N; Y+ {/ `/ FWhen measuring a voltage between earth and a conductor in a circuit that will not* }4 T0 A& s" }, S( S
be earthed in the intended application of the equipment, a non-inductive resistor of 5 000 Ω ± c3 x& K, ?8 _, y6 s4 K
10 % shall be connected across the voltage measuring instrument." A( g3 K, X8 A! O" i; W. F! y
为什么这种情况需要加这5 000 Ω ±10 %的无感电阻?
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- H- b: w7 P. Z* E, `2)根据定义,SELV电路是在正常状态和单一故障状态都不超过安全限值。若SELV电路和危险电压达到双重绝缘或加强绝缘(这种情况故障不考虑),那SELV电路保护接地是不是多余的? |
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