BS 4683-4:1973

Co-operating organizations
Introduction
Foreword
Specification
1 Scope
2 Definitions
3 General constructional requirements
3.1 Inlet devices for cables and insulated conductors
3.2 Terminals for external wiring
3.3 Internal connections
3.4 Clearances
3.5 Creepage distances
3.6 Solid insulating materials
3.7 Windings
3.8 Limiting temperature and critical limiting
     temperatures
4 Influence of ambient conditions
4.1 Protection against ingress of solid foreign bodies
     and liquids
4.2 Ambient temperature
4.3 Protection against unauthorized interference
4.4 Internal wiring
5 Particular requirements
5.1 Rotating machines
5.2 Control resistors for slip-ring motors
5.3 Luminaires (lighting fittings) designed for mains
     supply
5.4 Hand-lamps and cap-lamps with their own source of
     supply
5.5 Measuring instruments and measuring transformers
5.6 Other apparatus
6 Type tests
6.1 Experimental tests
6.2 Rotating machines
6.3 Luminaires designed for mains supply
6.4 Hand-lamps and cap-lamps with their own source of
     supply
6.5 Measuring instruments and measuring transformers
6.6 Other agreed type tests
7 Routine tests
8 Marking
Appendices
A Text deleted
B Method of control of the temperature of cage rotor
     motors in service
C Impact tests
D Particular requirements for the type testing of
     cage rotor motors
E Alignment with IEC Publication 79-7
Tables
1 Minimum clearance distances in air
2 Grades of insulating materials
3 Minimum creepage distances for rated voltages
4 Temperature class and limiting temperature with
     regard to gas ignition
5 Limiting temperature and limiting temperature rise
     with regard to insulation of windings
6 Standards of enclosures with ventilation openings
7 Minimum air-gap for machines with rolling-element
     bearings
8 Resistance to the effect of short-circuit currents
9 Impact tests of luminaires
Figures
1 Minimum value of the time tE of the motor in
     relation to the starting current ratio IA/IN
2 Schematic example of a cable inlet to explain the
     terminology used
3 Determination of creepage distances
4 Schematic diagram explaining the method of
     determination of time tE

Relates to the construction and test of electrical apparatus, type of protection \'e\'. This type of protection can only be applied to such kinds of electrical apparatus, or parts of apparatus, as do not produce sparks or arcs or dangerous temperatures in normal service. The measures to be applied in order to increase the safety of such apparatus, so that it is suitable for operation in areas endangered by explosive gas atmospheres, are specified.