Specifications

M GD-100 M anual
44 6109-9000 Rev 3
Section 7. Troubleshooting
Symptom Possible Cause(s)
No lights
displayed on
panel
• Power failure (check supply)
• Tripped circuit breaker or blown fuse on
electrical supply
• Blown fuse at the electrical supply on the
controller PCB board
Red light is on,
but no alarm
condition is active
(i.e., no siren and
no relay
operation aft er 3
minutes)
• Make sure the siren has not been deacti vat ed
(key switch on two-alarm, controll ers, link on
jumper JP1 on one-alarm controllers
removed).
• This indicates a wiring or sensor fault (call
service provider). If these are in order the
calibration pot may have been adjusted and
may need to be reset. Check with us for
instructions.
Controller is on,
but the MGD-100
is not
• This may indicate a wiring fault between the
controller and sensor or a sensor fault.
Check power supply to the cont roller. Check
connections between the controller and the
sensor to ens ure that the wires from positions
1 to 4 on the sensor are connected to the
corresponding 1-4 on the controller.
• On a 4 to 6 channel unit check that the sensor
fuse on the particular sensor connection
position in the controller is not blown.
NOT E: If fals e alarms are being t riggered by background
gases, paint fumes, etc., or extreme humidity or temperature
conditions, you may adjust the settings to compensate.
One-Alarm S y ste m s: You should reduce the SSV level in
0.5V increments until the condition clears.
Two-Alarm System s: You should adjust the rel evant alarm
threshold voltage upwards in 0.2 V increm ents until the
condition clears.
To make sure the gas det ectors are wired up correctly you can check the
voltages at the sens or cable terminal blocks on the controller PCB or
sensor PCB using a voltmeter as outlined bel ow in Table 1.