AGS Merlin TFT User manual

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 1
Merlin Gas Detector TFT
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Installation & Operation Manual
Please read this manual carefully and retain for future use.
At American Gas Safety, we supply a full range of remote gas detectors including carbon monoxide (CO),
natural gas (NG) and liquid petroleum gas (LPG) that are compatible with our range of Merlin panels.
The information contained within this manual should be referenced for typical installation and operation
only. For specific requirements that may deviate from the information in this guide –contact your supplier.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 2
CONTENTS
INSTALLATION........................................................................................... 3
Planning ...........................................................................................................................3
Typical Location and Positioning ................................................................................3
Typical Installation Arrangement ................................................................................4
Fixing .................................................................................................................................4
Board Overview..............................................................................................................5
Wiring the Detector .......................................................................................................5
Merlin -X- Systems ...........................................................................................................5
Merlin -S- Systems............................................................................................................7
Merlin -GDP- Systems .....................................................................................................7
X Chain ID Switches .......................................................................................................8
Audible Alarm Switch ....................................................................................................8
Factory Set Condition ...................................................................................................8
Trouble Shooting.............................................................................................................9
Specification ...................................................................................................................9
OPERATION.............................................................................................. 10
First Power Up ................................................................................................................10
Gas Level Indicators ....................................................................................................10
End of Life Indicator.....................................................................................................10
Testing the System........................................................................................................11
Service & Maintenance..............................................................................................11
Bump Testing .................................................................................................................12
IMPORTANT WARNING STATEMENTS................................................... 13
Manufacturer’s Warranty ...........................................................................................13
Installation Details ........................................................................................................16

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 3
INSTALLATION
Planning
Our detectors should be installed in areas at risk of gas leaks e.g. over boilers, valves or meters.
Take in to account the design of the air flow patterns within the zone area.
Detectors should be installed in the correct orientation, as recommended by the manufacturer,
and ease of access should be accounted for to allow for any bump tests, recalibration and
other forms of maintenance.
Areas to avoid
Avoid conditions of any other environmental factors that could potentially impede the
accuracy and operation of the detectors such as; condensation; vibration; temperature,
pressure, the presence of other gases, electromagnetic interference and draft zones.
Area of coverage
Consider the coverage required and function of the area. Emphasis should be placed on airflow
patterns and correct placement, not perceived detecting ranges. The target gas will only be
identified when contact is made with the sensing element itself.
Maximum Gas Detectors Per Zone
Merlin ‘S’ panel range
1
Merlin ‘GDP’ panel range
3
Merlin ‘GDP-X’ panel range
4
Typical Location and Positioning
Locations for detectors will vary based on the intended application and target gas, they should
be located near identified sources of a potential gas leaks/ pockets where hazardous gas could
quickly accumulate and areas of identified consequential risk.
The composition of the target gas and its density relative to air are used as the basis for the
recommended height of sensors. Generally, the installation height of a sensor for a heavy gas
(such as propane) would be close to the lowest point in the area, and for a light gas (such as
methane) would be close to the highest point in the area.
These recommended heights may vary based on air flow and temperature conditions in
addition to the proposed application and location –this is particularly apparent with oxygen
depletion sensors, and the target gas that they are used for.
Target Gas
Typical Detector Position
Natural Gas/Methane (NG/CH4)
High Level - 1ft from ceiling
Liquid Petroleum Gas (LPG)
Low Level - 1ft from ground level
Carbon Monoxide (CO)
Breathing Zone - 5ft 6” from ground level
Hydrogen (H)
High Level - 1ft from ceiling
Oxygen (O2)
*Breathing Zone - 3 - 5ft from ground level
* If you are installing and monitoring Oxygen depletion –consider the density of gas for its
application and position the detector accordingly i.e. ground level for high density gases.
Multiple detectors may be required to
adequately protect property and persons.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 4
Typical Installation Arrangement
Many detection systems are designed around a centralised control unit of which the location
also needs to be considered. They should be located outside of the hazardous area that they
are monitoring.
Easy accessibility is required both for status observation and alarm purposes.
The use of sound strobes are highly recommended.
Fixing
Unpack all the parts!
1. Carefully remove the rear cover from the unit by releasing
the two latching clips located at the bottom of the case.
To do this –use a small flat head screwdriver.
2. Using the rear cover - mark the screw holes to the wall.
Ensure the wall surface is flat to prevent base distortion.
3. There are two pre-fractured areas for cable entry provided
on the inside of the rear cover which may be cut away as
required.
4. After executing the mounting and the connections –replace
the rear cover ensuring the two clips are latched.
5. Make a note of the installation date on the label located on the side of the unit.
Be careful when creating access for cables –Damage to boards will void any warranty.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 5
Board Overview
Wiring the Detector
Merlin -X- Systems
12-24V Power and data supply via [DETECTOR X CHAIN] terminal and Merlin GDP-X range
terminal [DETECTOR CHAIN]. Detectors can be wired in any configuration [IN/OUT], [IN/IN],
[OUT/IN] etc.
Do not attempt to remove the Circuit Board! This will void any warranty.

Installation & Operation Manual Merlin Gas Detector TFT
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Multiple Detector Chain System - Typical Wiring Example
Chain System Termination Switches
120ohm Chain Termination Resistor Switch Signal communication issues may occur
where the bus length is too long or high baud rates are used. In this instance –terminating
at each end of the chain may help the quality of the data signal.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 7
Merlin -S- Systems
12-24V power supply via Power Input [+ -] and ‘S’ panel [GAS DETECTOR] terminal.
Building Management Systems (BMS)
If you are connecting to ‘S’ range you will need to use [NC/COM] terminals as an alarm relay.
These are volt free connections to building management systems.
A relay will change state when in alarm or when gas is detected.
BMS terminals can be used in conjunction with other external relays that affect other devices
and controls such as purge fans and audible alarms etc.
Merlin -GDP- Systems
12-24V power supply via Power Input [+ / -] and GDP panel [GAS DETECTION ZONE] terminal.
If you are using our ‘GDP’ range you will need to use the [C/L] terminal as an alarm relay.
A relay will change state when in alarm or when gas is detected.
BMS terminals can be used in conjunction with other external relays that affect other devices
and controls such as purge fans and audible alarms etc.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 8
X Chain ID Switches
When wiring multiple detectors to the
GDP-X range it is important to identify
each detector and in which monitoring
zone the detector is located - for the
GDP-X system to receive and display
accurate data.
The diagram opposite shows how to
configure switches for each detector and
is also printed onto the detector circuit
board for quick reference.
For more information - refer to your GDP-X manual.
Audible Alarm Switch
There is a switch on the detector-TFT board [Buzzer On/Off].
The user can choose whether to have an audible alarm
when dangerous gas levels are detected.
The alarm will continuously sound –there are no provisions to
silence the alarm, gas levels must drop to a safe level for the
alarm to stop.
The buzzer measures approx. 65dB from a distance of 300mm/1ft (tested in quiet conditions).
Factory Set Condition
Buzzer On/Off Switch
ON –see ‘Audible Alarm Switch’.
Chain Termination Resistor
OFF –see ‘Chain Wiring Example’.
Detector ID Switches
ID 1 –see ‘X Chain ID Switches’.

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 9
Trouble Shooting
Fault.
Possible Cause/Correction.
Detector not responding.
oIncorrect wiring.
oID switches not properly configured.
oTermination switches not set up correctly.
Fault message on screen
oGas sensor element knocked or damaged.
Service message on screen
oDetector requires service –contact supplier.
End of Life message on screen
oDetector requires replacement –contact supplier,
Specification
Product:
Gas Detector TFT (X)
Model:
CO / NG / LPG / H / O2
Visual Indicators
Green, Yellow & Red Visual Reading Indication
Gas Level / Measuring Value / Detector ID No / Detector Serial No
End of Life / Sensor Fault / Service
Display
1.8” TFT –Thin Film Transistor
Screen Brightness
Non- adjustable
Initial Stabilisation Time
60 Seconds approx.
Power Input Voltage
12-24V / 7-30VDC
Relay Output
0.5A Switching Current (resistive load).
Consumption
90mA Max (24V)
Accuracy @ 25°C / 77°F
± 5%
Fuses
N/A
Operating Temp
32 –122°F 30-85%RH Non-Condensing
Test Conditions
77° ± 41°F
Audible Alarm Buzzer (dB)
65 dB (300mm distance in quiet conditions)
Gas Sensor Type
NG: Semi-conductor
Measuring Range
NG: 300-10,000 PPM
LPG: Semi-conductor
LPG: 300-10,000 PPM
H: Semi-conductor
H: 100-10,000 PPM
CO: Electro-Chemical
CO: 10-10,000 PPM
O2: Electro-Chemical
O2: 0-30%
Gas Level Pre- Alarm
NG: 8% LEL
Gas Level Alarm
NG: 10% LEL
LPG: 8% LEL
LPG: 10% LEL
H: 8% LEL
H: 10% LEL
CO: 20 PPM
CO: 20 PPM @ 2 HOURS
O2: 18.5 –19.5%
50 PPM @ 1 HOUR
100 PPM @ 10 MINS
Expected Sensor Life
NG: 10 Years
300 PPM @ 1 MINS
LPG: 10 Years
O2: < 18.5% / >23%
H: 10 Years
CO: 5 Years
O2: 3 Years
Dimensions (H x W x D)
5.51 x 3.74 x 1.18”

Installation & Operation Manual Merlin Gas Detector TFT
AGSDETTFT-IOM Iss: 5 06-20 10
OPERATION
First Power Up
On connecting power, the detector enters ‘sensor stabilisation’ phase for approximately 60
seconds –during this period the screen will display an ‘initialisation’ message
indicating that the device is not yet ready for gas detection.
When the sensor has stabilised –the screen will display;
a. the relevant gas type intended to be detected
b. detected gas level in the area
c. the measurement value
d. the detector unique serial number
e. the detector ID number
Gas Level Indicators
End of Life Indicator
This message indicates that the detector has reached its expected operational lifecycle.
No gas levels will be displayed. Contact your supplier and replace the unit immediately.
SAFE
Safe gas levels will be
displayed GREEN.
ATTENTION!
Low gas levels will be
displayed YELLOW.
DANGER!
Dangerous gas levels
will be displayed RED.
The expected lifecycle will depend on the type of gas your detector is
targeting and may vary depending on environmental conditions.
At dangerous gas levels, the alarm will continuously sound if the buzzer dip-switch is ON.
There are no provisions to silence this alarm.
Only when gas levels are at a safe level will the audible alarm stop.