All electrical equipment in hazardous locations shall be installed in terms of SANS 10086 -1; SANS 10086-2; and SANS 10086-3.
Conduit installations are best done in heavy-gauge solid drawn or seam-welded tube with at least five full threads at joints to prevent moisture ingress. Stopper boxes should be used in conduits feeding from safe areas, to prevent the transmission of flammable gases.
Mineral insulated cables should be used to feed equipment installed in areas where vibration occurs. Rubber seals on gland assemblies should be checked to ensure correct seating and periodically to check for brittleness or deterioration. It is important at the design stage to anticipate what effect the chemicals present at the hazardous location will have upon the component parts of the installation. PVC, for example, will harden and crack when exposed to most solvents such as petrol, whilst general-purpose rubbers will soften when exposed to oils as well as solvents.
Damage to equipment can invalidate explosion proof qualities of cables and terminations, hence leading to a potentially dangerous situation especially in the case of flameproof equipment. Drilling holes in protected equipment to facilitate ease of mounting is definitely not permitted.
Automatic electrical protection, earthing and the provision of effective means for complete circuit isolation, including the neutral, must be incorporated in the installation. Suitable wiring systems should be chosen and particular care must be taken in the connecting of cables to protected equipment. Unused entries in apparatus must be stopped off with suitable plugs according to the type of protection used.
Once the installation is complete, it has to be tested and this can be a problem because of the danger of creating a spark and igniting the inflammable atmosphere, thus any tests should be carried out when the location has been made safe i.e. by halting production, etc.
Light fittings being only one of the electrical items used within the hazardous environment also need to be checked and serviced regularly and special care must be taken when relamping to see that machine faces are not corrosion pitted or gaskets damaged, that glands are still tight and not corroded and finally, that the sealing screws and devices are all tightly replaced and none missing.