AGS GDP2 Merlin Gas Detection System Instruction Manual
- June 13, 2024
- AGS
Table of Contents
MERLIN GDP2 Safe Area Gas Detector Controller
GDP2 Merlin Gas Detection System
Installation, Operation & Maintenance
Please read this manual carefully and retain for future use.
AGS provide a range of detection panels which can be used in many applications
such as factories, car parks, shopping centres and boiler houses. The GDP2 is
used with up to six (6) gas detectors in a single cable run for monitoring and
detecting gas in zones considered safe including CO, LPG and NG.
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.
Important Warning Statements
Please take the time to thoroughly read these instructions which should be
retained for future reference.
Detectors are shipped pre-calibrated and configured.
The expected lifetime of a gas sensor is 3-10 years upon initial power up
dependant on your target gas and environmental factors. The device will
display a message to indicate this time and should immediately be replaced.
It is recommended that this device be commissioned upon installation and
serviced annually by a competent person.
Do not apply lighter gas or other aerosols to the device – this will cause
extreme damage to the sensors.
High concentrations of alcohol found in many products may damage, deteriorate
or affect the gas sensing elements.
This device is designed to detect the gas type displayed on the screen only.
It is not designed to detect smoke, fire or other gases and should not be used
as such.
This device provides early warning of the presence of gas, usually before a
healthy adult would experience symptoms.
This warning is possible provided your alarm is installed and maintained in
accordance with this manual.
Never ignore your device when in alarm.
This device requires a continual supply of electrical power – it will not work
without power.
This device should not be used to substitute proper installation, use and/or
maintenance of fuel burning appliances including appropriate ventilation and
exhaust systems.
Multiple detectors may be required to adequately protect property and persons.
This device does not prevent dangerous gasses from occurring or accumulating.
Actuation of your alarm indicates the presence of dangerous levels of gas.
The device is not intended for use in potentially explosive atmospheres.
Seek fresh air supply and contact your local gas emergency service should you
suspect a gas leak.
This unit may not fully safeguard individuals with specific medical
conditions. If in doubt, consult a doctor/physician.
Your product should reach you in perfect condition, if you suspect it is
damaged, contact your supplier.
Manufacturer’s Warranty
Warranty coverage: The manufacturer warrants to the original consumer
purchaser, that this product will be free of defects in material and
workmanship for a period of three (3) years from date of purchase or one (1)
years for oxygen detectors.
The manufacturer’s liability hereunder is limited to replacement of the
product with repaired product at the discretion of the manufacturer. This
warranty is void if the product has been damaged by accident, unreasonable
use, neglect, tampering or other causes not arising from defects in material
or workmanship. This warranty extends to the original consumer purchaser of
the product only. Warranty disclaimers: Any implied warranties arising out of
this sale, including but not limited to the implied warranties of description,
merchantability and intended operational purpose, are limited in duration to
the above warranty period.
In no event shall the manufacturer be liable for loss of use of this product
or for any indirect, special, incidental or consequential damages, or costs,
or expenses incurred by the consumer or any other user of this product,
whether due to a breach of contract, negligence, strict liability in tort or
otherwise. The manufacturer shall have no liability for any personal injury,
property damage or any special, incidental, contingent or consequential damage
of any kind resulting from gas leakage, fire or explosion. This warranty does
not affect your statutory rights. Warranty Performance: During the above
warranty period, your product will be replaced with a comparable product if
the defective product is returned together with proof of purchase date. The
replacement product will be in warranty for the remainder of the original
warranty period or for six months – whichever is the greatest.
Information on waste disposal for consumers of electrical & electronic
equipment.
**** When this product has reached the end of its life it must be treated as
Waste Electrical & Electronics Equipment (WEEE).
Any WEEE marked products must not be mixed with general household waste, but
kept separate for the treatment, recovery and recycling of the materials used.
Please contact your supplier or local authority for details of recycling
schemes in your area.
At the end of their working life, electrochemical sensors for oxygen and
carbon monoxide detectors should be disposed of in an environmentally safe
manner. Alternatively they can be securely packaged and returned to AGS
clearly marked for disposal.
Electrochemical sensors should not be incinerated as this may cause the cell
to emit toxic fumes.
Installation
Typical Application, Location & Positioning
The Merlin GDP2 is a multi-safe zone gas detection panel which can be used in
many applications such as factories, car parks, shopping centres and most
commonly – boiler houses. It can be used with up to 8 Merlin gas detectors for
monitoring and detecting gas including carbon monoxide, liquid petroleum gas
and methane.
The controller panel can be integrated with, but not limited to, a BMS
(building management system), a fire panel, external alarms and remote
emergency shut-off buttons.
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 any recommended height of detector placement. Generally, the
installation height of a detector 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.
Any 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 Position |
---|---|
Natural Gas/Methane (NG) | High Level – 300mm (1ft) from ceiling |
Liquid Petroleum Gas (LPG) | Low Level – 300mm (1ft) from ground level |
Carbon Monoxide (CO) | Breathing Zone – 1700mm (5ft 6”) from ground level |
Hydrogen (H) | High Level – 300mm (1ft) from ceiling |
Oxygen (O2) | *Breathing Zone – 1000-1500mm (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.
The control panel should be located away from the area that it is monitoring and accessible is for both status observation and alarm purposes. The control panel should be located outside of the hazardous area that it is monitoring. Easy access is required both for status observation and alarm purposes.
Access & Mounting
Unpack all the parts!
Designed for surface mounting, it must be installed by a licensed, insured contractor or competent person.
Carefully remove the front cover from the unit by unscrewing the four bolts located at each corner. To do this – use the socket wrench provided. Mark the four screw holes located on the back of the enclosure to the wall and ensure the wall surface is flat to prevent base distortion.
After executing the mounting and the connections – replace the front cover and insert the security caps over the four bolts. Access to the interior of the panel, when carrying out any work, must be conducted by a competent person.
Before carrying out any work ensure local regulations and site procedures are followed.
We recommend all Merlin gas detection equipment and systems are commissioned by a competent/trained engineer to ensure correct installation and operation. Contact AGS for more information.
Internal Board Overview- 100-120VAC Mains power Input
- 100-120VAC Gas Solenoid Valve Output.
- 24VDC Gas detector power supply (Zone 1)
- 24VDC Gas detector power supply (zone 2)
- Remote emergency stop buttons
- Heat Sensor: Fusible Links
- Fire panel connection
- BMS output contacts.
- 24VDC Sounder/ Strobe alarm
- Switch – BMS Selection & Auto Reset
- Switch – Zone 1, 2, 3 & 4 enable/disable
Note: Terminal blocks are
plug/socket type and may be removed to ease wiring.
Be careful when creating access for cables – Damage to circuit boards will
void any warranty!
Detectors are sold separately and shipped pre-calibrated and configured!
Board Connections Overview
POWER/LINE IN 100-120vac mains power is supplied to the [POWER/LINE IN]
connector using a 3-core cable fused at 3A. On connecting the mains supply,
power LED indicator will light up – this is located on the front.
GAS VALVE 100-120vac electrical power output from the [VALVE OUT] terminal
using a 3-core cable to a gas solenoid valve, which can shut the gas supply on
alarm status.
GAS DETECTOR (Zones 1 – 2) 24vdc power supply to gas detectors are wired to
[GAS DETECTOR ZONE] terminals. For more information, see section: Wiring your
detector.
EM REMOTE An open/close switch for remote emergency shut-off buttons detailed
as [EM STOP].
HEAT SENSOR An open/close switch for heat sensors/ thermal links detailed as
[HEAT SENSOR].
FIRE PANEL An open/close switch for fire alarms detailed on the circuit board
as [FIRE PANEL].
BMS OUTPUT Connections are available on the board for Building Management
Systems. These are volt free connections. This is a relay that changes state
in alarm or when the gas is on/off and used in conjunction with the 24vdc
output and other external relays that affect other devices and controls such
as purge fans and audible alarms etc.
SOUNDER-STROBE 24vdc output for an external sounder alarm/ strobe lighting to
activate on alarm.
Wiring your Detector
Power is supplied to a detector via the GDP terminal [+ / -] and using the
panel [GAS DETECTION ZONE] terminal.
If you are using a GDP panel you will need to use the detector [C/L] terminal
as an alarm relay.
BMS Switch
The GDP2 can be integrated with a BMS to make or break a circuit on gas on/gas
off, (valve open or valve closed).
This will tell the BMS whether or not electrical power is being sent to the
solenoid. There is a dip-switch located on the GDP2 circuit board labelled
[BMS]. This is factory set to ‘OFF’ position which signals the BMS on gas
on/gas off.
When switched to ‘ON’, the GDP2 will only signal the BMS on a fault, i.e. gas
detected, EM Stop pressed, etc.
BMS SWITCH | BMS SIGNAL |
---|---|
OFF | Gas on or off only. |
ON | Error condition i.e. gas detected, emergency stop pressed. |
Auto Reset Switch
The panel has a built-in auto reset feature. There is a dipswitch located on
the circuit board labelled [AUTO RESET].
This is factory set in the ‘Off’ position i.e. when power is restored after a
power cut or loss, the panel has to be restarted manually. When enabled, the
system will restart automatically when power is restored and can be reset
following a fire alarm and when the alarm is cleared.
AUTO SWITCH | CONDITION |
---|---|
OFF | Panel has to be restarted manually following a power cut/loss and/or |
alarm.
ON| Panel will automatically restart when power is restored and can be reset
remotely via a fire panel.
Zone 1 – 2 Set-Up Switches
There are dipswitches located on the GDP2 circuit board labelled [ZONE 1] and
[ZONE 2].
This is factory set in the ‘Off’ position. For each of the gas detector zones
you are using please ensure that the relevant zone has being enabled. The zone
you are not using should be left disabled.
ZONE 1/2/3/4 SWITCH | CONDITION |
---|---|
OFF | Gas detection zone disabled. |
ON | Gas detection zone enabled. |
Factory Set Condition
SWITCH | CONDITION |
---|---|
BMS | OFF |
AUTO RESET | OFF |
ZONE 1 | OFF |
ZONE 2 | OFF |
Trouble Shooting
Operation
Initial Power-Up (Commissioning)
On connecting mains power, press reset to start the testing sequence. The
system will close the solenoid valve when an emergency stop has been pressed,
gas has been detected or any alarm signal has been triggered.
When the system is connected to the mains power supply, the Power LED will
illuminate RED.
LED Indicator Status
Power
Power LED will illuminate RED when power is supplied. When no power is
present, this LED will not light up.
Gas On
On start up the Gas on LED will flash for one minute to check for gas
detected. If no gas detected or any other faults the gas valve will open and
the Gas On LED will illuminate. GREEN = Gas On OFF = Gas Off If the test is
unsuccessful, the relevant zone LED light will illuminate to indicate a fault.
EM Stop
If an emergency shut off button (either remote or on the panel) is pressed,
the LED will illuminate AMBER and the gas will be turned off. The EM Stop
button must be re-set before restarting the system.
Heat Detector
If the fusible link melts at >72° C, the LED will illuminate AMBER and the gas
valve will de-energise.
Fire Alarm
On a fire alarm, the LED illuminates AMBER and gas supply isolated. The alarm
must be reset before restarting the system. Off = OK AMBER = Fire alarm
activated.
Zones 1-2
Under normal working conditions this LED is GREEN. If the gas detector
connected reaches the low level alarm this will show AMBER. If the gas
detector connected reaches high level alarm this will show RED and the gas
solenoid valve will close.
Mute & Reset Buttons
MUTE The mute button is located on the front fascia of the GDP2 and is used
to mute the sounder inside the board when in alarm. The internal buzzer
operates at approximately >60db measured 30cm (1ft) from a closed panel. The
mute button is used to mute the sounder inside the board when in alarm.
RESET The reset button is located on the front fascia of the GDP2 and is used
to turn the system on and to reset the system following alarm.
General Maintenance
Cleaning
Keep your gas detector in good working order – follow these basic principles;
- Remove any dust/debris from the outer enclosure regularly using a slightly damp cloth.
- Never use detergents or solvents to clean your device.
- Never spray air fresheners, hair spray, paint or other aerosols near the device.
- Never paint the device. Paint will seal vents and interfere with the device.
Concentrations of alcohol found in many products may damage, deteriorate or
affect the gas sensing elements such as; wine; deodorants; stain removers and
thinners. Other gases and substances to avoid are; corrosives (i.e. chlorine &
hydrogen chloride); alkali metals; basic or acidic compounds; silicones;
tetraethyl lead; halogens and halogenated compounds!
Manual Circuit Simulation Test
When the test button on the circuit board is pressed and held for ~3s the
detector will simulate an open circuit to ensure outputs, alarms, indications
and external devices etc. operate as intended in response to gas.
Access to the interior of the detector, when carrying out any work, must be
conducted by a competent person! This test does not check the gas-sensing
element itself!
Bump Test (Gas Response Check)
What is a Bump Test?
Gas response checks are often referred to as a ‘bump test’. Bump tests are
important to make sure a device is able to detect a release of gas as early as
possible. The aim of the bump test is to make sure a detector is working at
its optimum by briefly exposing the unit to a known concentration of the
target gas that usually exceeds the highest alarm point. If the detector goes
into alarm and all signals/outputs activate, then the system is working
safely. If the system fails to operate as intended in an alarm state, the gas
detector must not be used until a full inspection and service has been
conducted.
Why is it important?
A detector may visually appear in good working order, but its sensitivity can
be inhibited by external factors. Dust, humidity, temperature fluctuations,
cleaning products, contaminants or sensor drift (ageing) can cause a decline
in sensitivity and eventual failure.
How often?
Regular bump tests are important to make sure the detector is able to detect a
release of gas as early as possible and usually takes seconds (gas type
dependant i.e. CO sensors will take over a minute) and is often completed
alongside a scheduled fire alarm test, however the frequency should be
determined following an appropriate risk assessment by the end user. Remember,
bump testing does not remove the need to have gas detectors inspected,
calibrated and serviced periodically by a competent person.
What do I need?
Contact your AGS representative for details of suitable bump testing kits and
gases. Kits usually consist of a certified gas cylinder; flow control
regulator, tube pipe and applicator cone. We recommend only using AGS
calibration gas kits to ensure correct flow rates meet AGS technical
requirements. A bump testing gas is usually a concentration mix that exceeds
the highest alarm set point.
See below for recommended gas concentrations for bump testing your
detector.
Detector Type | Bump Test Gas | Response Time |
---|---|---|
CO – Carbon Monoxide | 400 – 500ppm (balance in air). | <120s |
NG – Methane | 0.6 – 0.8% BV (balance in air) | <30s |
LPG – Liquid Petroleum Gas | 0.3 – 0.4% BV (balance in air) | <30s |
H – Hydrogen | 5000 – 6000ppm (balance in air) | <30s |
O2 – Oxygen | 15% (balance in Nitrogen). | <60s |
All certified test gases supplied by AGS are classified as non-flammable and
non-toxic; however, they do contain gas under pressure and may explode if
heated to extreme temperatures and cause asphyxiation in high concentrations.
How to perform a Bump Test?
-
Ensure you have the correct gas for the device type prior to application.
-
Screw and seal the regulator/valve into the gas cylinder outlet.
-
Once sealed, the regulator pressure gauge will indicate cylinder pressure.
-
Offer up the applicator hose/cone to the lower vents.
-
Open the valve/regulator to allow the gas to be delivered at a pre-set flow rate.
-
Wait for the device to enter alarm status and energise configured outputs/relays.
At this point… -
Remove applicator hose/ cone and turn the gas cylinder regulator/valve off.
-
Wait for the device to return to normal.
-
Reset the system if required. Record your test details.
Notes:
To increase reaction time, cover the escape vents at the top of the device.
Alternatively, enclose the device and apply gas i.e. in an airtight bag or
container.
For more help and advice on bump testing – contact us.
Always remove the regulator/valve from cylinder after use!
Always check cylinder pressure upon sealing valve – there may not be a
sufficient amount of gas!
All AGS cylinders will re-seal upon removal of the regulator/valve!
Always give at least five (5) minutes between testing the same unit or until
gas has fully dispersed!
Always consider safety and use equipment in accordance with Safety Data
Sheets!
End of Operational Life (EOL)
The typical life of a gas detector depends on its application and intended
target gas, in addition, the operational life can be prolonged if the system
and equipment is installed and maintained in accordance the instructions
stated within this manual.
- Natural Gas /Methane: 10 Years approx.
- Liquid Petroleum Gas: 10 Years approx.
- Hydrogen: 10 Years approx.
- Carbon Monoxide: 5 Years approx.
At the end of this time, contact your supplier and replace the unit immediately.
Specification
General
Product:| GDP2 Gas Detector Controller
Use:| Indoor, Safe Areas (not to be used in potentially explosive atmospheres
Indicators| LED
Mounting| Wall Mounting
Electrical
Max. Power Consumption| 20W Max (Full Load)
Power Voltage Input Range| 100-120vac
Gas Valve Output Range| 100-120vac
I/Os| 24vdc Outputs (Detector / Strobe or Sounder)
3x Open/Close Switches (EM Stop / Heat Sensor / Fire Panel)
BMS| Volt Free (Normally Closed / Common / Normally Open) 3A Max
Relay(s)| 2x 120vac 10A (Latching Switch)
Terminal Wire ratings| Copper 18AWG (0.75mm2) Min. x29 screw terminals.
Fuse| 3.15A
Construction
Dimensions (H x W x D)| 140 x 190 x 62mm (5.51 x 7.48 x 2.44”)
Unit Weight (Approx.)| 0.7kg / 24.7oz
Housing Material| Polylac – PA765
Environmental
Ingress Protection| IP65 (Pre-installation)
Storage Conditions| Dry. Cool. Flat
Operating Conditions| -10 ~ 50°C / 14 ~ 122°F 30 ~ 80% rf
Compliance
CE| EN 61326-1 / BS EN IEC 61010-1
Installation Details
Please pass this manual to the system owner / user.
Date of Installation:|
---|---
Installation Location:|
Organisation:|
Stamp/Signature of the installer:|
We recommend all Merlin gas detection equipment be commissioned by a
competent/trained engineer to ensure correct installation and operation. The
Merlin range of gas detectors are calibrated when manufactured, however, we
strongly recommend the detectors response and alarm signals are tested and
validated once installed. This will ensure the equipment performs as intended
and is free from any unforeseen damage caused by transit/installation.
Every effort is made to ensure the accuracy of this document; however, AGS can
assume no responsibility for any errors or omissions in this document or their
consequences. AGS would greatly appreciate being informed of any errors or
omissions that may be found in the content of this document. For information
not covered in this document, or if there is a requirement to send
comments/corrections, please contact AGS using the contact details given
below.
American Gas Safety LLC
Head office:
6304 Benjamin Road, Suite 502, Tampa, FL 33634
Tel: 727-608-4375
info@americangassafety.com
American Gas Safety LLC is the owner of this document and reserves all rights
of modification without prior notice.
Rev: 10 01-22
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