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Detector Information
Detector location will vary dependant on the individual characteristics of the target gas that is being monitored for.
The descriptions below describe the position for each detector after considering these characteristics.
For proper function, care must be taken not to site a detector in a “dead space” or in the direct flow of any ventilation.
Natural Gas/Methane
Natural gas detectors should be mounted at high level on a wall approximately 150mm from the ceiling height and avoiding
corners and potential dead air areas.
Natural gas detectors should not be mounted below the height of the top of a doorway for example. This is because as the gas
is slightly lighter than air it will rise filling the room from the ceiling down and will spill through the top of a door opening into the
next room. If the detectors are mounted below this height then it will take longer the gas to reach the detector.
LPG /Propane
LPG gas is heavier than air so detectors need to be mounted at low level 100mm from the floor, consideration should be given
to any potential mopping or wet floor height.
Carbon Monoxide
Carbon Monoxide is similarly weighted to air so detectors should be mounted between 1 to 2 meters from the floor.
Carbon Dioxide
Carbon Dioxide detectors should be installed so they monitor the general level of CO2 within the area. They should be mounted
above standing head height and between 1m and 3m from the potential source. Care should be taken so they are not located
close to the edge of a canopy or in direct flow of the supply or extract ventilation.
For additional information or guidance on site specific requirements please don’t hesitate to contact us.
Each detector has its own Bi-Colour LED which is used to indicate the status of that detector.
Not Lit:
No power/comm’s. These are four wire units and all connections are required
(0v, +VE, MA, MB)
, check
the polarity of both the power and the comm’s (MA/MB) terminals are correct.
Flashing Green:
Detector is warming up, the detectors will flash green on power up for 90 seconds while the sensor
elements stabilize. The system will ignore any detectors while flashing.
Solid Green:
Detector is powered and active.
Note
:
The detectors will still require correctly addressing (using the address
selector pot) and learning by the system using button
23, (see page 5)
.
Flashing Red:
Low level alarm. All detectors have both a low and high level alarm, low level alarms serve as a warning
that an unsafe condition maybe building and gives chance to intervene before loss of gas service.
Solid Red
High level alarm. An unsafe level of the target gas have been reached and the system will isolate the
gas supply. The cause of the alarm will require identifying and resolving before the gas supply can be re-
established.
After installation a simple bump test can be performed by using an appropriate level test gas in order to check operation. Full
testing and calibration checking takes place during a Medem commissioning.
Detector Location
Detector Indications
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