Hi folks,
I have a question about the Class II equipment with functional earth. It is easy to think that functional earth does not provide MOP at location where large fault current (e.g. short circuit) may occur. The standard therefore requires two MOPs between internal screens, including internal wiring connected to them and ACCESSIBLE PARTS.
But I am a little bit confused on the wording for insulation the standard used which mentioned above. I can at least think of 3 scenes:
1) The internal screen functionally earthed is not separated from MAINS, then two MOPs required from internal screen to accessible part. (In line with standard requirement)
2) The internal screen functionally earthed is separated from MAINS by one MOP, then an additional one MOP from internal screen to accessible part is sufficient.
3) The internal screen functionally earthed is separated from MAINS by two MOPs, then no insulation required between internal screen and accessible part.
Any other opinions?
Thanks,
Roland
I have a question about the Class II equipment with functional earth. It is easy to think that functional earth does not provide MOP at location where large fault current (e.g. short circuit) may occur. The standard therefore requires two MOPs between internal screens, including internal wiring connected to them and ACCESSIBLE PARTS.
But I am a little bit confused on the wording for insulation the standard used which mentioned above. I can at least think of 3 scenes:
1) The internal screen functionally earthed is not separated from MAINS, then two MOPs required from internal screen to accessible part. (In line with standard requirement)
2) The internal screen functionally earthed is separated from MAINS by one MOP, then an additional one MOP from internal screen to accessible part is sufficient.
3) The internal screen functionally earthed is separated from MAINS by two MOPs, then no insulation required between internal screen and accessible part.
Any other opinions?
Thanks,
Roland