Before Submitting for Certification Check That the Product Can Comply with the Relevant
Before submitting for Certification check that the product can comply with the relevant clauses of:
Increased Safety – Ex e
IEC 60079-7
Requirements for all “Ex e” electrical apparatus
Terminals for External connection.
Internal connections.
Clearances.
Creepage distances.
Solid Insulation – Mouldings and other materials – comparative tracking index (CTI).
Windings - Winding wire specification minimum conductor size - Class of insulation.
Temperature limits – material stability – surface temperatures, inside & outside.
Rotating electrical “Ex e” machines
Clean environment degrees of protection.
Internal and external fan clearances and materials.
Minimum radial air gap.
Machines with cage rotors – rotor bar security against sparking.
Possible air gap sparking and risk assessment.
Limiting temperature of rotors not greater than 300 0C or below ignition point of explosive gas.
Starting current ratio IA/IN not greater than 10.
VVVF Motor Drives to be tested with specified converter.
Polyphase windings to have additional insulation between random windings.
Specific requirements for coil impregnation.
Equipotential bonding of multi-section enclosures.
Shaft seals of non-sparking materials.
Stator winding terminals not to exceed limiting temperature.
Assessment of HV machines – Ignition risk factors – explosive gas tests.
Luminaires designed for mains supply
Light source – fluorescent lamps single pin caps (Fa6), bi-pin with G5 or G13 caps, tungsten filament for general lighting service to IEC 60064 and IEC 60432.
Other lamps.
Lampholders and caps.
Requirements for electrical contact between lampholder and lamp cap.
Specific requirements for lampholders and caps include mechanical and electrical tests.
Where an isolating switch is fitted, it must provide safe clearances and operation.
Portable lights with their own supply for Group II require guarding and special electrical requirements.
Measuring instruments and transformers
Continuous overcurrent or overvoltage capabilities are required.
Short-circuit current withstand for CT’s and Instruments.
Requirements for transformers other than instrument transformers.
Batteries
Secondary batteries with capacity greater than 25 Ah to be of lead-acid, nickel-iron or nickel-cadmium.
Battery containers, insulating barriers and covers and the materials used must be to standard.
Adequate ventilation and a specified degree of protection to be provided.
Plugs and sockets are to comply with the General Requirements standard.
Cell construction and connections between to be of a specified type.
Primary and secondary batteries up to 25 Ah only to be connected in simple series.
Only batteries in accordance with the Tables to be used. Primary batteries shall not be re-charged.
Reference to the Standard must be made to ensure that all requirements can be met.
Resistance Heaters (other than trace heating) are not considered to be windings. They must however comply with the relevant sections of the General Requirements, and this standard, and the surface temperature is always below the ignition temperature of the potentially explosive atmosphere.