60 illustrates this arrangement. The emergency supply usually provided battery
contained within the luminaire, together with the charger and relay, mak-
ing the unit self-contained. 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. 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.30 shows trunking which provides for segregation circuits.
.60
Non-maintained emergency lighting.
The batteries used for the emergency supply should suitable for this pur-
pose.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. 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.
Definition
In non-maintained system the emer-
gency lamps are only illuminated if
the normal mains supply fails. 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.1). Motor vehicle batteries are not suitable for emergency lighting appli-
cations, except the starter system motor-driven generators. The battery room of
a central battery system must well ventilated and, the case motor-
driven generator, adequately heated ensure rapid starting cold weather.
Transformer
Supply
Normally
open relay
Rectifier
Emergency
supply
Emergency
lamp
FIGURE 14.
Figure 14. Figure 14. The fuel
supply motor-driven generator should checked.
The disadvantage with this type installation that broken lamps are not
detected until they are called into operation emergency, unless reg-
ularly maintained
