SPECIAL REQUIREMENTS FOR ELECTRONIC EQUIPMENT

3.2   SPECIAL REQUIREMENTS

FOR ELECTRONIC EQUIPMENT

PART 1‏     REQUIREMENTS

3.2.1.1‏ CONSTRUCTION

Electronic components of communication systems, security systems and special systems and electronic components forming part of the power generation and distribution system are to be solid-state integrated construction, unless otherwise approved.

3.2.1.2‏ TEMPERATURE LIMITS

Manufacturer is to indicate maximum and minimum ambient temperatures acceptable for the equipment to operate continuously and normally and beyond which electronic components may suffer permanent damage.

3.2.1.3 ALTERNATIVE ELECTRONIC EQUIPMENT

May be submitted for approval, provided such equipment meets or exceeds the functional capabilities and/or performance parameters of the equipment specified.  Proposals for alternative equipment will be considered only if accompanied by the following information:

-‏      List of operational characteristics and performance parameters

-‏      ‏List of differences in operation and performance between proposal and specified equipment

-‏      List of changes required and resulting implications

-‏      ‏Drawings indicating changes required to system wiring

-‏      Statement of advantages of proposed equipment over that specified 

3.2.1.4‏ PROTECTION

Solid state equipment under normal conditions of operation is to withstand any surges which might be produced by sudden mains or standby power switching operations.  Protective devices are to be provided to protect against surges, failure of output stages due to open circuit, short-circuit or mis-match.

3.2.1.5‏ INDICATOR LIGHTS

Other than LV pilot lamps are to be light emitting diodes (LEDs).

3.2.1.6‏ ELECTROMAGNETIC RELAYS

Control/small power transformers are to be designed to withstand the 500 V a.c. test voltage between winding and winding or winding and core.

3.2.1.7‏ DUST COVERS

Easily removable for inspection and servicing, are to be provided for all relays and sensitive elements.

3.2.1.8‏ OUTDOOR EQUIPMENT

Electronic or other, is to be designed for maximum ambient temperature or direct sun and is to be protected/enclosed, as applicable, against dust and weather conditions.

3.2.1.9‏ EXTERNAL INTERFERENCE

Carry out field investigations and tests to determine possible interference from outside sources, and design electronic equipment to ensure trouble-free operation.

3.2.1.10‏      SEGREGATION OF WIRING

Design wiring so that low current circuits are segregated from power wiring, using different conduits and wire-ways for the purpose.  Composite wiring will be acceptable for the same system in accordance with the relevant codes; cable insulation is to be of same grade for all conductors in a common enclosure.

3.2.1.11‏      POWER SUPPLY UNITS

For low current systems which are fed from the LV supply are    to be independently fused on the live conductor and are to have front panel mains indicator light, on/off switch and standard cartridge type fuse holder.  Blown fuse indicator    lamp is to be provided when fuse does not have an indicator.

End Of This Section