PROEL PRO EVAC SYSTEM, Системное руководство

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7
LOOP FEEDBACK
The feedback loop line is necessary to check the loudspeakers line continuity. To ensure an
effectual control, the loudspeakers installation must be configured to have one sole line and is
connected to all loudspeakers without derivation ( daisy chain connection) . To the first diagnostic
module must be connected the first loudspeaker and to the second loudspeakers so on …to the
last loudspeaker. To this last loudspeaker must be connected the couple of loop wire .
In this way it is possible to check eventual interruptions due line short circuit as stated in point “j”
paragraph 5.3 of EN 60849 standards.
The line circuit default survey is effected by the diagnostic system but there is no commutation in
case of line interruption (short circuit) . The loudspeakers connected to the line section
continuously connected to the zone module are powered normally ( for example line interruption at
a certain point).
Obviously the system can not check the single loudspeaker status ( not required by EN 60849
standards) at the exception to a great line impedance decrease due to the consequent signal
attenuation and then tone pilot absence.