Servicing your alarm system, the basics .......
1: MAINS PHASE NEUTRAL TEST. AC voltage between Live
and Neutral.
This should measure between 220 - 250VAC.
MAINS PHASE EARTH TEST: AC voltage between Live and
Earth.
This should be the same as the previous reading.
MAINS NEUTRAL EARTH TEST: AC voltage between
Neutral and Earth.
This reading should not exceed 1.2VAC.
2: POWER SUPPLY TEST: Transformer AC voltage output.
This should measure between 14 - 21VAC.
3: POWER SUPPLY CURRENT NORMAL TEST: AC current used
by system when unset.
Measure with meter in series with the transformer
output.
4: POWER SUPPLY CURRENT IN ALARM TEST: AC current used
by system when in alarm. As step 3.
5: INDUCED AC TEST: AC voltage between DC+ and earth.
AC noise should not exceed 1.2 volts max.
6: BATTERY CHARGING VOLTAGE TEST: DC voltage at
battery terminals.
Measure with charge leads connected to the battery.
7: PANEL AUXILIARY DC VOLTAGE TEST: DC voltage supply
to detectors.
Should be within ±1volt of the battery charging
voltage.
8: BATTERY FLOAT CHARGE TEST: DC mA current flowing
through battery.
Should fall from a double mA figure to a single mA
figure within 30 seconds.
9: BATTERY SYSTEM CURRENT NORMAL TEST: DC current used
by system when unset.
Ideally, not more than 5% of the batteries Ah
capacity.
10: BATTERY SYSTEM CURRENT IN ALARM TEST: DC current
used by system when in alarm. Ideally, not more
than 10% of the batteries Ah capacity.
11: BATTERY TEST: Record Temperature, Voltage °C DCV Ah
and Capacity available. Replace battery when
reading falls below 65% of Ah capacity.
12: CIRCUIT RESISTANCE TESTS: Record all circuit
resistances. Circuits must be removed from control
panel before testing.
13: CIRCUIT EARTH LEAKAGE TEST: Check for resistance
between zone, tamper and earth. Test with meter on
highest Meg Ohm range.
14: BELL TAMPER RETURN TEST: Record resistance between
0Volt and removed tamper return. Check for stable
resistance. Ring bell to induce vibration.
15: PANEL ZONE WALK TEST: Walk test all detection zones
to confirm operation.
Check each circuit operates normally, especially
after lightning.
16: SELF-ACTIVATING BELL TEST: Remove hold-off voltage
to confirm operation. Replace if defective.
17: BELL & STROBE TEST: Activate bell and strobe to
confirm operation. Replace if defective.
18: WIRING AND CONNECTIONS: Check panel for incorrect
or loose wiring connections. Check all cables are
marked and connected correctly.
19: DETECTOR VOLTAGE TEST: Check voltage at furthest
detector is above 13VDC.
Low or unstable DC voltage at the detector is a
main cause of false alarms.
1: MAINS PHASE NEUTRAL TEST. AC voltage between Live
and Neutral.
This should measure between 220 - 250VAC.
MAINS PHASE EARTH TEST: AC voltage between Live and
Earth.
This should be the same as the previous reading.
MAINS NEUTRAL EARTH TEST: AC voltage between
Neutral and Earth.
This reading should not exceed 1.2VAC.
2: POWER SUPPLY TEST: Transformer AC voltage output.
This should measure between 14 - 21VAC.
3: POWER SUPPLY CURRENT NORMAL TEST: AC current used
by system when unset.
Measure with meter in series with the transformer
output.
4: POWER SUPPLY CURRENT IN ALARM TEST: AC current used
by system when in alarm. As step 3.
5: INDUCED AC TEST: AC voltage between DC+ and earth.
AC noise should not exceed 1.2 volts max.
6: BATTERY CHARGING VOLTAGE TEST: DC voltage at
battery terminals.
Measure with charge leads connected to the battery.
7: PANEL AUXILIARY DC VOLTAGE TEST: DC voltage supply
to detectors.
Should be within ±1volt of the battery charging
voltage.
8: BATTERY FLOAT CHARGE TEST: DC mA current flowing
through battery.
Should fall from a double mA figure to a single mA
figure within 30 seconds.
9: BATTERY SYSTEM CURRENT NORMAL TEST: DC current used
by system when unset.
Ideally, not more than 5% of the batteries Ah
capacity.
10: BATTERY SYSTEM CURRENT IN ALARM TEST: DC current
used by system when in alarm. Ideally, not more
than 10% of the batteries Ah capacity.
11: BATTERY TEST: Record Temperature, Voltage °C DCV Ah
and Capacity available. Replace battery when
reading falls below 65% of Ah capacity.
12: CIRCUIT RESISTANCE TESTS: Record all circuit
resistances. Circuits must be removed from control
panel before testing.
13: CIRCUIT EARTH LEAKAGE TEST: Check for resistance
between zone, tamper and earth. Test with meter on
highest Meg Ohm range.
14: BELL TAMPER RETURN TEST: Record resistance between
0Volt and removed tamper return. Check for stable
resistance. Ring bell to induce vibration.
15: PANEL ZONE WALK TEST: Walk test all detection zones
to confirm operation.
Check each circuit operates normally, especially
after lightning.
16: SELF-ACTIVATING BELL TEST: Remove hold-off voltage
to confirm operation. Replace if defective.
17: BELL & STROBE TEST: Activate bell and strobe to
confirm operation. Replace if defective.
18: WIRING AND CONNECTIONS: Check panel for incorrect
or loose wiring connections. Check all cables are
marked and connected correctly.
19: DETECTOR VOLTAGE TEST: Check voltage at furthest
detector is above 13VDC.
Low or unstable DC voltage at the detector is a
main cause of false alarms.
