Vasilevski
Junior Member level 2
Hello all,
I have a task to modify a power supply in accordance with IEC 60601-1 (3d edition) and provide 2 MOPP safety.
Sometimes it's not easy to me to understand what this standard requires because I've never deal with it before. Here my question:
In the section "8.9 * CREEPAGE DISTANCES and AIR CLEARANCES" the first two clauses say:
"8.9.1.1 General
CREEPAGE DISTANCES and AIR CLEARANCES of ME EQUIPMENT shall be equal to or greater than the values of Table 11 to Table 16 (inclusive) except as specified in 8.9.1.2 to 8.9.1.15. See also 8.9.2 to 8.9.4.
8.9.1.2 CREEPAGE DISTANCES and AIR CLEARANCES complying with IEC 60950-1
The values of Table 11 to Table 16 (inclusive) do not apply to CREEPAGE DISTANCES and AIR CLEARANCES forming MEANS OF OPERATOR PROTECTION that comply with the requirements of IEC 60950-1 for INSULATION CO-ORDINATION and are used in the conditions (e.g. overvoltage category, pollution degree) under which compliance was tested."
The table 11 has appearance:
**broken link removed**
I haven't found any other refinements in a body of standard how to use this table, so I believe air clearences and creepage distances are shown in table 11 must be followed for any case ( except 8.9.1.2, as I understand, this is not my case).
So, what does it mean "parts of opposite polarity of the MAINS PART" in the head of the Table 11? As I'm concerned, "opposite polarity" means two potentials which have different polarity - "+" and "-" (i.e. above and below a zero level).
My power supply consists of standard PFC module and DC/DC converter which is connected to PFC output. Do the requarements of the standard mean that I must provide clearances and creepages thru entire design except Parts which are insulated with 2 Means of protection (these are part after power transformer and some parts of control circuits)? If my guess about "opposite polarity" is right, may be the stadard requires to follow values from the Table 11 only before diode bridge in the PFC part? I mean after diode bridge we will have only one polarity - positive (i.e. above a zero level).
I have a task to modify a power supply in accordance with IEC 60601-1 (3d edition) and provide 2 MOPP safety.
Sometimes it's not easy to me to understand what this standard requires because I've never deal with it before. Here my question:
In the section "8.9 * CREEPAGE DISTANCES and AIR CLEARANCES" the first two clauses say:
"8.9.1.1 General
CREEPAGE DISTANCES and AIR CLEARANCES of ME EQUIPMENT shall be equal to or greater than the values of Table 11 to Table 16 (inclusive) except as specified in 8.9.1.2 to 8.9.1.15. See also 8.9.2 to 8.9.4.
8.9.1.2 CREEPAGE DISTANCES and AIR CLEARANCES complying with IEC 60950-1
The values of Table 11 to Table 16 (inclusive) do not apply to CREEPAGE DISTANCES and AIR CLEARANCES forming MEANS OF OPERATOR PROTECTION that comply with the requirements of IEC 60950-1 for INSULATION CO-ORDINATION and are used in the conditions (e.g. overvoltage category, pollution degree) under which compliance was tested."
The table 11 has appearance:
**broken link removed**
I haven't found any other refinements in a body of standard how to use this table, so I believe air clearences and creepage distances are shown in table 11 must be followed for any case ( except 8.9.1.2, as I understand, this is not my case).
So, what does it mean "parts of opposite polarity of the MAINS PART" in the head of the Table 11? As I'm concerned, "opposite polarity" means two potentials which have different polarity - "+" and "-" (i.e. above and below a zero level).
My power supply consists of standard PFC module and DC/DC converter which is connected to PFC output. Do the requarements of the standard mean that I must provide clearances and creepages thru entire design except Parts which are insulated with 2 Means of protection (these are part after power transformer and some parts of control circuits)? If my guess about "opposite polarity" is right, may be the stadard requires to follow values from the Table 11 only before diode bridge in the PFC part? I mean after diode bridge we will have only one polarity - positive (i.e. above a zero level).