AGS GDP2 Merlin Gas Detector i-S Installation Guide
- June 9, 2024
- AGS
Table of Contents
Merlin Gas Detector i-S
Combustible Gases NG
(Natural Gas) / LPG (Propane) / H2 (Hydrogen)
Safe Area Safety Monitoring – General Gas Detection
Installation, Operation & Maintenance
Please read this manual carefully and retain for future use.
For specific requirements that may deviate from the information in this guide
– contact your supplier.
American Gas Safety LLC
www.americangassafety.com
Important Warning Statements
Warning Symbol!
Where this symbol is used, the manual must be consulted to understand the
nature of any potential hazards and how to avoid them.
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 10 years upon initial power up
dependant on your target gas and environmental factors. The device will
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 may cause
extreme damage to the sensors.
High concentrations of alcohol found in many products may damage, deteriorate,
or affect the gas sensing elements.
This product 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.
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.
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!
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.
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 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
Installation must be carried out by a licenced, insured contractor!
Ensure that detectors are not exposed to liquid or dust contamination!
Detectors and cables must be protected against mechanical damage!
Avoid conditions of any other environmental factors outside of the
specification that could potentially impede the accuracy
and operation of the detector such as condensation; vibration; temperature,
pressure, the presence of other gases, electromagnetic interference, and draft
zones!
The target gas will only be identified when contact is made with the sensing
element itself!
Gas detectors should be installed in areas at risk of gas leaks e.g., near
boilers, valves, or meters, located in positions determined by those who have
knowledge of gas dispersion, the process plant system and equipment involved,
and in consultation with both safety and electrical engineering personnel.
Take in to account the design of the air flow patterns within the area.
Detectors should be installed in the correct orientation, as recommended, and
ease of access should be accounted for to allow for any bump tests and other
forms of maintenance throughout its operating life.
There are no official figures of the area coverage of a gas detector; however,
50m2 per detector is a reasonable general guide therefore multiple detectors
may be required to adequately protect property and persons. There are no
specific standards governing gas detector location (unlike fire detection
systems); there are, however, general guidance documents. The most relevant
being IEC 60079-29-2:
Explosive Atmospheres – Part 29: Gas detectors – Selection, installation, use
and maintenance of detectors for flammable gases and oxygen. Much of what it
covers is also relevant to toxic gas detection.
Recommended heights may vary based on air flow and temperature conditions in
addition to the proposed application and location. 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 gas
could quickly accumulate and areas of identified consequential risk to detect
gas. 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 (e.g., 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 typical positions 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 (NG) | High Level – 1ft (300mm) from highest point |
Propane (LPG) | Low Level – 1ft (300mm) from lowest point |
Hydrogen (H2) | High Level – 1ft (300mm) from highest point |
If you are installing and monitoring oxygen depletion monitors – consider the
density of gas for its application and position the detector accordingly i.e.,
ground level for high-density gases.
Detectors should be mounted where a potential hazard of gas is most likely to
be present. The following points should be noted also when locating gas
sensors. When locating detectors consider
- The possible damage caused by natural events e.g., rain or flooding.
- Ease of access to the gas detector for functional testing and servicing.
- How gas may behave due to natural or forced air currents.
Mounting & Cabling
If mounting direct to wall – ensure the wall surface is flat to prevent base
distortion!
Ensure the rear base is installed in the correct orientation as shown!
Where cable glands/conduits are used for wire entry, use 20mm (3/4 inch) max
separated by at least 20mm!
Any parts that form part of the connections/installation must have a minimum
fire-retardant rating of UL94v-2!
Damage to PCBs when creating cable entry points or attempting to remove the
circuit board may void any warranty!
The monitor is designed for either surface mounting or mounted on a one or two
gang electrical box.
Restrain the hazardous live wiring from accidental loosening to prevent wires
from moving after installation and touching parts of opposite polarity or at
low voltages!
Isolate the equipment from all hazardous live power sources before opening the
cover!
- Carefully remove the front cover from the unit by using an M3 socket wrench.
- Using the rear base – mark mounting holes to the wall or align with a vertical 2-gang/pattress box.
- Fixing straight to wall – drill 0.2” (5mm) hole, insert plugs and use the four screws (No.4 Pozi) provided.
- There are pre-fractured areas for cable entry on the rear of the base and pilot holes positioned on the top and bottom of the enclosure suitable for entry points up to ¾” (20mm). Drill out as necessary ensuring all swarf is removed from the box and holes have smooth edges.
- After executing the mounting/connections – secure the front cover with all M4 bolts and insert security caps provided.
Circuit Board Overview
Damage to PCBs when creating cable entry points may void any warranty!
Any damage attempting to remove the circuit board may void any warranty!
A disconnector is required and accessible for the 24V supply and an adequate
overcurrent device is fitted!
Wiring: Power Input
Standalone Power
Power can be provided either 24Vac or 12-24Vdc.
Terminals are pluggable type to ease connections.
Merlin GDP Controller – Power Connection
Power is supplied via the GDP terminal [+ / -].
Use the [C/L] terminal as an alarm relay.
Wire in parallel for multiple detectors.
Merlin Gas Proving Controller – Power Connection
Power is supplied via the 24VDC terminal [+ / -].
Use the open/close terminal as an alarm relay to detectors.
Wiring: Alarm Relays
These are dry contact connections to a BMS (building management systems) or
Merlin panel to send an alarm signal upon pre/alarm levels of gas. Max 1A load
@ 12/24Vdc or ac.
If you are connecting detector(s) via a GDP panel you will need to use the
[C/L] terminal as an alarm relay.
A relay will change state when in alarm or pre-alarm when gas is detected and
if wired/configured to do so. These terminals can be used in conjunction with
other external relays that affect other devices and controls such as purge
fans and audible alarms etc.
Alarm Relay Setting Switch – Latch On/Off
The switch is left off as a factory set condition!
This switch is used to latch/unlatch an alarm relay.
When turned on the detector relay will latch permanently on (until reset) in
the event of the detector detecting gas and entering an alarm state.
The audible alarm will alert the user that the detector entered an alarm
state. To reset the Detector, press and hold the touch button for ~3 seconds.
Wiring: 0-10V Analogue Output
This connection is used to regulate external fan speed controllers (supplied
separately). Connect direct to fan speed controllers or via your Merlin panel
[0-10V] terminal if available. 0-10V output is driven by the status of gas
concentrations detected.
0-10V Output | 1V | 2V | 3V | 4V | 5V | 6V | 7V | 8V | 9V | 10V |
---|---|---|---|---|---|---|---|---|---|---|
Gas Level (% LEL) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
Audible Buzzer Switch
There is a switch on the detector board identified as [Buzzer On/Off].
The detector can be configured to have an audible alarm or not when gas levels
reach the main alarm set points. The alarm will continuously sound – there are
no provisions to silence the alarm, gas levels must drop to a safe value for
the alarm to stop.
Factory Set Condition
Detectors are shipped pre-calibrated and configured.
Buzzer On/Off Switch | On |
---|---|
Alarm Relay Setting Switch | Off |
Operation
Initial Power Up
On connecting power, the detector enters a warmup phase for approximately 60 seconds – during this period, your device not yet ready for operation.
Latched Relay Alarm & Reset
The switch is left off as a factory set condition!
The detector will indicate a red dot on the screen when the alarm relay has
latched.
The audible alarm will alert the user that the detector has entered a main
alarm state. To reset the detector, press and hold the touch sensor for ~3s.
Alarm Set Points
An audible buzzer will sound if the buzzer switch on the circuit board is on!
Low Pre-Alarm | Buzzer | High Main Alarm | Buzzer |
---|---|---|---|
▲ 8% LEL | None | ▲ 10% LEL | Continuous sound |
▲ Rising alarm ▼ Falling alarm / LEL – Lower Explosive Level
Maintenance
Cleaning
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!
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.
Manual Circuit Simulation Test
Access to the interior of the detector, when carrying out any work, must be
conducted by a competent person!
This circuit test does not check the gas-sensing element itself!
When the test button on the circuit board is pressed and held for ~3seconds
the detector will simulate an open circuit to ensure configured systems,
outputs, alarms, indications, and other external devices operate as intended
in response to gas.
The test sequence will automatically terminate after a short period of time
and return to normal operation.
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 can 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 and
accuracy can be inhibited by external factors. Dust, humidity, temperature
fluctuations, cleaning products, contaminants, exposure to its target gas or
sensor drift (ageing) can cause a decline in sensitivity, accuracy, and
eventual failure.
How often?
Regular bump tests are important to make sure the detector can detect a
release of gas as early as possible and usually takes seconds (gas type
dependent 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. We
recommend testing detectors every 12-18 months along with the regular fire
test procedures and coincide with the annual service message prompted on the
detection system after each year of service/operation.
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 or spray. 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.
Bump Test Procedure
To increase reaction time, cover the escape vents at the sides of the device.
Always remove the regulator/valve if using a cylinder after use!
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!
Reference should always be given to any applicable national & local law and
industry codes.
Generally, the gas concentration should be greater than the alarm threshold of
the device.
Always remove the regulator/valve after use if using a cylinder!
All cylinders will re-seal upon removal of the regulator/valve!
Deviating from this test process is deemed improper and may affect the
functional safety of your device!
Exposure to chemicals, smoke, or any other materials other than the gases
intended to be monitored can seriously damage the gas sensing elements!
Always allow a minimum of 5 minutes before testing the same unit!
- Ensure you have the correct gas for the device type prior to application.
- Offer up the applicator hose/cone or spray to the small vents of the device located underneath.
- Apply gas.
- The device will enter alarm status after reaching alarm set point.
- The device will activate all configured outputs/relays.
- Reset by pressing and holding the touch sensor for ~3s.
- Test complete.
- Record your test details.
End of Operational Life (EOL)
The EOL is approximate from the first five (5) hours of continuous power!
The EOL will depend on the type of gas your detector is targeting and may vary
depending on its application and environmental conditions such as the
frequency of exposure to the target gas, poisons, or inhibitors! 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.
At the end of its predicted operational life – the detector will display an
‘End of Life’ screen. This message indicates that the detector has reached its
expected operational lifecycle and no gas levels are displayed.
You must contact your supplier immediately for replacement.
Specification
General
Product:| Merlin Detector i-S
Models (Target Gas):| – NG (Natural Gas)
– LPG (Propane)
– H2 (Hydrogen)
Size: (H x W x D)| 5.95 x 4.37 x 1.97” (151 x 111 x 50mm)
Housing Material:| ABS PA765. Flame Retardant UL 94V-1
Mounting:| Safe Zone – Indoor use – Wall Mounted
Weight:| 212g
User Interface
Display:| 1.8” TFT
Screen Brightness:| Non-Adjustable
Visual Indicators:| Gas Level (Green: Normal; Yellow: Pre-Alarm; Red: Alarm)
0-10V Output: Relay Output
Audible Alarm:| >65dB @ 3.28ft (1m). Quiet conditions.
Language:| English
Power Supply
Rated Power:| 1.8W Max
Rated Voltage:| 12-24Vdc or 24Vac
Relays
Dry contact relay outputs:| 1A switching current (resistive load) @ 24V AC/DC
Environmental
Ingress Protection (IP):| Not Formally Evaluated
Operating:| -10 ~ 50°C / 20 ~ 90% RH (non-condensing)
Storage:| 0 ~ 50°C / 30 – 80% RH (no condensation)
Altitude Rating:| 2000m
Wiring
Typical| Min. 2.5mm2 / 75°C min / Tinned copper.
Compliance
Electrical Safety & EMC| CE / UKCA BS EN 61010-1:2010 +A1:2019. & BS EN 50270.
Sensor Specification
Gas Detector i Model| Measuring Range| Steps| Response
(t90)| Recovery (t10)| LOW (Pre-Alarm)| HIGH (Main
Alarm)| *EOL (Years)
Semi-Conductor
NG (Natural Gas)| 0-10% LEL| 0.1| <60s| <60s| ▲8% LEL| ▲10% LEL| 10
LPG (Propane)
H2 (Hydrogen)
Installation Details
Please pass this manual to the system owner / user.
Date of Installation:|
---|---
Installation Location:|
Organization:|
Stamp/Signature of the installer:|
We recommend all Merlin gas detection equipment be commissioned by
competent/trained engineers 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.
American Gas Safety LLC
www.americangassafety.com
Head office:
6304 Benjamin Road, Suite 502, Tampa, FL 33634
Tel: 727-608-4375
Email: info@americangassafety.com
American Gas Safety LLC is the owner of this document and reserves all rights of modification without prior notice.
References
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