Page 597 - Wago_PCB_TerminalBlocksConnectors_Volume2_2015_US

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• Insulation Parameters per IEC/EN 60664-1 (continued)

Pollution Degrees Dimensioning Clearances
Pollution factors are all solid, liquid or gaseous foreign matter which may reduce the per DIN EN 60664-1/ VDE 0110,
dielectric strength or the specific surface resistance. Factors are divided into 4 classes Part 1, Table F.2.
based on expected environmental conditions: Select the minimum clearances in accor-
dance with the rated surge voltages and
pollution degree. For the operating life of
Examples of pollution the equipment, do not go below these
degrees for assigned
areas: minimum clearances.
Pollution degree 1: No pollution, or only dry, non- Open, unprotected Table F.2 contains a list of information for
Case A, the inhomogeneous field and for
conductive pollution occurs. insulated equipment in air-
The pollution has no influence. conditioned or Case B, the homogeneous field.
clean, dry rooms. This involves an electric field with essen-
Pollution degree 2: Only non-conductive pollution Open, unprotected tially constant (Case B) or non-constant
occurs; occasional, temporary insulated equipment in (Case A) voltage gradients between the
conductivity caused by con- living areas, shops, electrodes.
densation can also be expect- laboratories, mechanical Equipment with a clearance in accor-
ed. workshops and medical dance with Case A, in other words
rooms.
rated for the most unfavorable case,
can be employed without evidence
of surge voltage testing.
Pollution degree 3: Conductive pollution occurs, or Open, unprotected insulat-
dry, non-conductive pollution ed equipment in industrial, Equipment whose clearances are dimen-
occurs which will become con- business and farming areas, sioned acc. to Case B, or between A and
ductive due to condensation. e.g., unheated rooms, work- B, requires verification by the surge volt-
shops and boiler rooms. age test.

The clearances shown in Table F.2 are
Pollution degree 4: The pollution generates persis- Open, unprotected applicable for an installation height of up
tent conductivity caused by insulated equipment for
conductive dust, rain or wet outdoor use. to 2000 m above sea level.
conditions.
Values for clearances above 2000 m
Table F.2: Clearances to Withstand Transient Overvoltages must be multiplied by a high correction
DIN EN 60664-1/ VDE 0110, Part 1 factor in accordance with Table A.2.
Minimum clearances in air up to 2000 m above sea level
Required Case A Case B
impulse with- (inhomogeneous field, see 3.15) homogeneous field (see 3.14)
stand volt- 6 6
age 1)5) Pollution degree Pollution degree
1 2 3 1 2 3
kV (mm) (mm) (mm) (mm) (mm) (mm) 1) Diese Spannung ist
0.33 2) 0.01 0.01 – for functional insulation: the maximum surge voltage
expected to occur across the clearance (see 5.1.5);
0.40 0.02 0.02 – for basic insulation directly exposed to or significantly
0.50 2) 0.04 0.2 3)4) 0.04 influenced by transient overvoltages from the low-volt-
0.60 0.06 4) 0.06 0.2 3)4) age mains (see 4.3.3.3, 4.3.3.4.1 and 5.1.6):
0.80 2) 0.10 0.8 0.10 and the rated surge voltage for the equipment;
1.0 0.15 0.15 0.8 4) – for other basic insulation (see 4.3.3.4.2): the
1.2 0.25 0.25 0.2 highest surge voltage that can occur in the circuit.
1.5 2) 0.5 0.5 0.3 0.3 for reinforced insulation, see 5.1.6.
2.0 1.0 1.0 1.0 0.45 0.45 2) Preferred values specified in 4.2.3.
2.5 2) 1.5 1.5 1.5 0.60 0.60 3) For printed wiring material, the values for pollution
3.0 2.0 2.0 2.0 0.80 0.80 degree 1 apply except that the value may not be less
4.0 2) 3.0 3.0 3.0 1.2 1.2 1.2 4) than 0.04 mm, as specified in Table F.4.
5.0 4.0 4.0 4.0 1.5 1.5 1.5 The minimum clearances given for pollution degree 2
and 3 are based on the reduced withstand characteris-
6.0 2) 5.5 5.5 5.5 2.0 2.0 2.0 tics of the associated creepage distance under humidity
8.0 2) 8.0 8.0 8.0 3.0 3.0 3.0 conditions (see IEC 60664-5).
10 11 11 11 3.5 3.5 3.5 5) For parts or circuit within equipment subject to surge
12 2) 14 14 14 4.5 4.5 4.5 voltages according to 4.3.3.4.2
15 18 18 18 5.5 5.5 5.5 interpolation of values is allowed. However, standard-
20 25 25 25 8.0 8.0 8.0 ization is achieved by using the preferred series of surge 13
25 33 33 33 10 10 10 voltage values based on 4.2.3.
30 40 40 40 12.5 12.5 12.5 6) The dimensions for pollution degree 4 are as specified
40 60 60 60 17 17 17 for pollution degree 3, except that the minimum clear-
ance is 1.6 mm.
50 75 75 75 22 22 22
60 90 90 90 27 27 27
80 130 130 130 35 35 35
100 170 170 170 45 45 45