Use of Y1 capacitors for MOPP (means of patient protection)

[BMR96]

Hello,


I would like to see if anyone can clarify a point on Y1 capacitors. Section 8.5.1.2 says that a Y1 cap can be used as 1 MOPP if it passes the dielectric strength test of 2 MOPP. I have heard it said, and it stands to reason, that to achieve 2 MOPP with Y1 caps, you simply put 2 caps in series. The standard gives guidelines for using Y1 caps in series, but it does not explicitly say that 2 caps in series will actually be equivalent to 2 MOPP. So, any thoughts on this? Is it as simple as 2 caps = 2 MOPP?


Thank you.

 

[Peter Selvey]

Yes, it is fairly common practice, and obviously the intended purpose of the statement about keeping the values the same capacitance.

Clause 8.5.1.1 is the basic clause that says 2 MOP are required, I guess that stays in the background.