ELECTRIC MOTOR SPECIFICATIONS ON TEMPERATURE CLASS AND OTHER TEMPERATURE RELATED CONSIDERATIONS GUIDE

ELECTRIC MOTOR SPECIFICATIONS ON TEMPERATURE CLASS AND OTHER TEMPERATURE RELATED CONSIDERATIONS GUIDE
How to specify electric motors using temperature class as basis?

Combustible gas or vapor and explosion-protected electrical equipment is divided into temperature classes T1 to T6 with regard to the ignition temperature of the gas or vapor and the maximum surface temperature of
the equipment. Refer to Table1.4A - Temperature Class. Ignition temperature, thermal flashpoint, is the lowest temperature of a surface at which a substance ignites on contact with the surface.

Hazardous area and zones
Hazardous areas are rooms, spaces or areas in which an explosive gas mixture may occur under conditions such that electrical equipment, among other things, may have to meet certain requirements.

Hazardous areas are categorized as zones as follows:

Zone 0 - An area in which an explosive gas atmosphere is present continuously or is present for long periods.
Zone 1 - An area in which an explosive gas atmosphere is likely to occur in normal operation.
Zone 2 - An area in which an explosive gas atmosphere is not likely to occur in normal operation and if it does occur it will exist for a short period only.

It is important that the mechanical design of installations should be such that hazardous areas should be few and of small extent. It should also be an aim to make hazardous areas chiefly Zone 2 areas.

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PARTS OF A POWER TRANSFORMER

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