Creepage distances and clearances s

Creepage distances and clearances shall not be less than the values in millimetres shown in Table 12. The values specified in the table do not apply to cross-over points of motor windings.The values in Table 12 are equal or larger than the values required by IEC 60664-1, when– an overvoltage category II;– a material group III;– a pollution degree 1 for parts protected against deposition of dirt and for lacquered or enamelled windings;– a pollution degree 3 for other parts;– inhomogeneous electric fieldare applied.If a resonance voltage occurs between the point where a winding and a capacitor are connected together, and metal parts which are separated from live parts by basic insulation only, the creepage distance and clearance shall not be less than the values specified for the value of the voltage imposed by the resonance, these values being increased by 4 mm in the case of reinforced insulation.Compliance is checked by measurement.For tools provided with an appliance inlet, the measurements are made with an appropriate connector inserted. For other tools, they are made on the tool as delivered.For tools provided with belts, the measurements are made with the belts in place, and the devices intended for varying the belt tension adjusted to the most unfavourable position within their range of adjustment, and also with the belts removed.Movable parts are placed in the most unfavourable position; nuts and screws with non-circular heads are assumed to be tightened in the most unfavourable position.The clearances between terminals and accessible metal parts are also measured with the screws or nuts unscrewed as far as possible, but the clearances shall then be not less than 50 % of the value shown in Table 12.Table 12 – Minimum creepage distances and clearancesDistances through slots or openings in external parts of insulating material are measured to metal foil in contact with the accessible surface; the foil is pushed into corners and the like by means of the test probe B of IEC 61032:1997, but it is not pressed into openings.If necessary, a force is applied to any point on internal wiring and bare conductors, other than those of heating elements, to any point on uninsulated metal capillary tubes of thermostats and similar devices, and to the outside of metal enclosures, in an endeavour to reduce the creepage distances and clearances while taking the measurements.