IGBT Modules - Technologies, Driver and Application (Second Edition) - page 121

IEC 60077-1
, "Railway applications – Electric equipment for rolling stock, Part
1: General service conditions and general rules".
IEC 60664-1
, "Insulation coordination for equipment within low-voltage
systems, Part 1: Principles, requirements and tests" and their annexes IEC
60664-1Amendment 1 and IEC 60664-1Amendment 2.
IEC 60664-3
, "Insulation coordination for equipment within low-voltage
systems, Part 3: Use of coating, potting or moulding for protection against
IEC 61800-5-1
, "Adjustable speed electrical power drive systems, Part 5-1:
safety requirements –Electrical, thermal and energy".
UL 508c
, "Power conversion equipment".
UL 840
, "Insulation Coordination including clearances and creepage distances
for electrical equipment".
Fig. 2.49
Clearanceand creepage distances
To determine the necessary distances, a series of preliminary tasks is required that
mainly involves specifying the operating and environmental conditions. One important
factor is the degree of contamination expected in the system, which is divided into fou
Pollution degree 1
means that no or only dry, non-conductive contamination
occurs, which has no influenceon the operation.
Pollution degree 2
assumes that, in normal circumstances, only non-
conductive contamination occurs. If the component is not being operated,
however, dew can cause slight conductivity.
Pollution degree 3
allows for conductive contamination caused, for example,
by a normally dry, non-conductive contamination, when dewoccurs.
Pollution degree 4
assumes ongoing conductive contamination, e.g. by
conductive dust, rainor snow.
Standard IEC 61287-1 for traction applications defines three further sub-categories in addition to these four
1...,111,112,113,114,115,116,117,118,119,120 122,123,124,125,126,127,128,129,130,131,...548
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