Zone Faults; Power Supply Faults - ADEMCO LST700 Series Insallation & Maintenance Manual

1.1 Zone Faults

■ To find out if an open circuit or head out fault has occurred on a detector zone:-
1. Remove the Panel's lid using the torx key provided and press the ACCESS LEVEL THREE
FUNCTIONS button on the Main Control PCB to gain access to the panel's engineer functions
(see below)
2. Continue pressing the ACCESS LEVEL THREE FUNCTIONS button until the OPEN CIRCUIT light pulses.
Any existing Zone fault indicators are suppressed and the Zone indicator(s) for any Zone(s)
with an open circuit or head out fault are illuminated. For example, if the wiring on Zone 6 is
broken or one of its detector heads have been removed, Zone 6's Fault indicator will be lit.
■ To find out if a short circuit fault has occurred on a detector zone:-
Follow steps 1 and 2 outlined above until the SHORT CIRCUIT light pulses.
Any existing zone fault indicators are suppressed and the zone indicator(s) for any zone (s)
that have a short circuit fault are illuminated. For example, if the wiring on zone 4 has been
shorted, zone 4's fault indicator will be lit.
To escape access level three, press the ESCAPE ACCESS button at any time.
Suggested action:
(a) Disconnect the faulty detector zone completely and refit the end-of-line capacitor at the
Panel. If the fault condition clears this confirms there is a wiring fault.
(b) Double check and refit the wiring and the end-of-line capacitor on the zone. Trace the fault
with consideration for the type of fault indicated (see above).
Note: a common short circuit fault is a detector head badly seated in a base which is not
making a true connection.

1.2 Power Supply Faults

A power supply fault is indicative of one or more of the following faults. Page 11 of this manual
must be referenced when carrying out any of the suggested action procedures described below.
■ The mains supply is too low or has failed completely.
Symptoms: the Panel runs on batteries, but not on mains. The red hazardous voltages
present light on the Power Supply PCB is lit.
Suggested action:
(a) Isolate the mains supply and remove the mains connector block (CONN1) from the Power
Supply PCB.
(b) Position the connector block so that the live and neutral connections can be probed.
Taking all due precaution, reapply the mains and measure the voltage.
(c) Isolate the mains supply again.
If the reading was incorrect (see Technical Specifications, page 24) repair the mains supply.
If the reading was correct, check to see if the primary mains fuse (F1) is ruptured.
If the fuse is intact and the red hazardous voltages present light on the Power Supply PCB is
lit, then the PSU is faulty and should be replaced.
This section is continued on page 20
LST700 SERIES INSTALLATION & MAINTENANCE MANUAL • Approved Document No. DFU7002012 Rev 4
SYSTEM REPEATER
FAULT
FAULT
SW8
COINCIDENCE
ACCESS
NONLATCHING
LEVEL THREE
FUNCTIONS
OPEN SHORT
CIRCUIT CIRCUIT
DELAYS TEST
LST700 SERIES FIRE ALARM PANEL
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