下文为标准：
6.5.4 PROTECTIVE IMPEDANCE
A PROTECTIVE IMPEDANCE shall limit the current or voltage to the levels of 6.3.1 in NORMAL
CONDITION and 6.3.2 in SINGLE FAULT CONDITION.
Insulation between the terminations of the PROTECTIVE IMPEDANCE shall meet the requirements
of 6.7 for DOUBLE INSULATION or REINFORCED INSULATION.
A PROTECTIVE IMPEDANCE shall be one or more of the following:
a) an appropriate single component which shall be constructed, selected and tested so that safety and reliability for protection against electric shock is assured. In particular, the component shall be:
1) RATED for twice the maximum WORKING VOLTAGE;
2) if a resistor, RATED for twice the power dissipation for the maximum WORKING VOLTAGE.
b) a combination of components.
A PROTECTIVE IMPEDANCE shall not be a single electronic device that employs electron
conduction in a vacuum, gas or semiconductor
Conformity is checked by inspection, by measuring the current or voltage to confirm that they
do not exceed the applicable levels of 6.3 and by measuring CLEARANCES and CREEPAGE
DISTANCES as specified in 6.7. Conformity of a single component is checked by inspection of
its RATINGS.作者: 志纤陶 时间: 2011-12-24 21:58
耐压值是指电容的工作时最大电压值，方案1其实和方案2是一样的，都是为了避免电容耐压击穿，作者: swk_sun 时间: 2011-12-24 21:58
认证机构是对的。
正确来说不应该叫耐压值，而是电压额定值是指CY1电容的最大正常工作电压，比如常见的有AC 400V。单个AC 400V的CY1电容按照新标准的规定，是不能用在250V工作电压的场合当中了。用在网电源场合的CY1电容至少是500V （2 x 250）。