Basic Electrical Installation Work

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The battery room of a central battery system must well ventilated and, the case motor- driven generator, adequately heated ensure rapid starting cold weather. Figure 14. The batteries used for the emergency supply should suitable for this pur- pose. The disadvantage with this type installation that broken lamps are not detected until they are called into operation emergency, unless reg- ularly maintained. Transformer Supply Normally open relay Rectifier Emergency supply Emergency lamp FIGURE 14. The emergency lighting installation must segregated completely from any other wiring, that fault the main electrical installation cannot damage the emergency lighting installation (IEE Regulation 528.60 illustrates this arrangement.Electrical installations and wiring systems 341 NON-MAINTAINED EMERGENCY LIGHTING In non-maintained system the emergency lamps are only illuminated if the normal mains supply fails. Motor vehicle batteries are not suitable for emergency lighting appli- cations, except the starter system motor-driven generators.30 shows trunking which provides for segregation circuits. When the normal supply restored, the relay solenoid energized, breaking the relay contacts, which disconnects the emergency lamps, and the charger recharges the battery. Maintenance The contractor installing the emergency lighting should provide test facil- ity which simple operate and secure against unauthorized interfer- ence.1).60 Non-maintained emergency lighting. Failure the main supply de-energizes sole- noid and relay connects the emergency lamps battery supply, which is maintained state readiness trickle charge from the normal mains supply. The fuel supply motor-driven generator should checked. Figure 14. Self-contained units are cheaper and easier to install than central battery system, but the central battery can have a greater capacity and duration, and permit range emergency lighting luminaires installed. The emergency supply usually provided battery contained within the luminaire, together with the charger and relay, mak- ing the unit self-contained. . Definition In non-maintained system the emer- gency lamps are only illuminated if the normal mains supply fails