Specifications

M GD-100 M anual
14 6109-9000 Rev 3
A void routing sensor c abling outside of premises, or between buil dings
via overhead cabl es. Also, sensor wiring should be kept to a minim um of
20 in (500mm) from the main power supply and telephone cables.
When connecting the main power supply and/ or sensor cables ensure a
second m echanic al fixing is used. Use a cable tie inside the enclosure
within 1 in (25m m) of the cable termination.
When power to the unit is switched on, there is a 3-minute delay before
the system activat es. This allows the sensors to warm up to the correct
temperature for gas detection. On a two-alarm unit, the green light on the
alarm panel comes on after the delay, indicating that the system is ready.
On a one-alarm system the green light comes on immediately. When a
unit has been off or stored for a long time the stabilizing period m ay be
longer than 3 minutes. After the 3 minutes has expi red, alarms may
activate. You may deacti vate the siren until stabilization is complet e.
(Use the key switch on t wo-alarm units. Remove jumper JP1 in the case
of a one-alarm unit).
Mount the controller using the mounting hol es in the base such that the
sensor cable terminal blocks are at the bottom of the unit in a convenient
position.
Sensors m ust be located within the appropriate wire l engt hs from the
controller.
In all cases the sensor supplied is designed for maximum sensitivity to a
particular gas. However, i n certai n circumstanc es false alarms m ay be
caused by the occasional presence of sufficiently high concentrations of
other gaseous impurities. Examples of situations where such
abnormalities may arise include the following:
• Plant room maintenance activity involving solvent or paint fumes
or refrigerant leaks.
• Accidental gas migration in fruit ripening/storage facilities
(bananas - ethylene, apples - carbon dioxide).
• Heavy localized exhaust fumes (carbon monoxide, dioxide,
propane) from engine-driven forklifts in confined spaces or close
to sensors.
A response delay is built in to the system to minimize the possibilities of
false alarms (for two-al arm units only) or it may be selected for one-
alarm units.