AGS Merlin 1500S Guide

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 1
Gas Safety Products
Merlin 1500S Gas Interlock System
Installation, operating and maintenance

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 2
Table of contents
1General information.............................................................................. 3
2Installation.............................................................................................. 3
2.1 Panel Mounting. ...................................................................................................3
2.2 Mains Supply. ........................................................................................................3
2.3 Gas solenoid valve. .............................................................................................3
2.4 Supply Fan & Extract Fan PD Switches. ............................................................3
2.5 BMS Connections. ................................................................................................3
2.6 Remote emergency shut off buttons. ..............................................................3
2.7 Gas Detector. .......................................................................................................3
2.8 FS 123. .....................................................................................................................3
2.9 CO2 Monitor..........................................................................................................3
2.10 12v DC....................................................................................................................3
2.11 Internal Buzzer. ......................................................................................................3
3Operation Instructions........................................................................... 4
3.1 How to turn the system on and off ...................................................................4
3.2 Explanation of LED status....................................................................................4
3.2.1 Power LED ..............................................................................................................4
3.2.2 Gas on LED ............................................................................................................4
3.2.3 Supply fans LED.....................................................................................................4
3.2.4 Extract fans LED ....................................................................................................4
3.2.5 Fan Fault LED .........................................................................................................4
3.2.6 EM Stop LED...........................................................................................................5
3.2.7 Gas Detected LED ...............................................................................................5
3.2.8 CO2 High LED........................................................................................................5
3.3 CO2MODE.............................................................................................................5
3.4 Using the emergency shut off............................................................................5
3.5 BMS integration.....................................................................................................6
3.6 Fire alarm integration ..........................................................................................6
3.7Fan switch integration .........................................................................................6
1500S Wiring Diagram .................................................................................. 7

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 3
1General Information
The Merlin 1500S is a ventilation interlock panel.
The Merlin 1500S can receive connections from up to four external remote air pressure
differential switches or current monitors, remote emergency shut-off buttons, gas detectors and
a Merlin CO2monitor. It can also be integrated with a BMS and fire alarm.
It is recommended that the user reads this guide before using the system. Please do NOT
attempt to operate the unit until the contents of this document have been read and are
thoroughly understood.
2Installation
2.1 Panel Mounting. The control panel is designed for surface mounting using 4 mounting
screws. Removing the cover on the panel gives access to the circuit board. The PCB should be
removed before drilling entry holes into the case.
2.2 Mains Supply. A 110-120VAC electrical supply should be supplied to the panel. This
should be externally fused at 3 Amps using a fused spur and should be connected to the
terminals marked [LNE Power].
2.3 Gas solenoid valve. The gas solenoid valve should be powered using the terminals on the
Merlin 1500S marked [LNE GAS VALVE].
2.4 Supply Fan & Extract Fan PD Switches These terminals are used to receive an input signal
from external air pressure switches or external current monitors. These are linked out as a factory
setting. Wiring should be made using two-core volt free connections. If only one fan is being
used the terminals not in use should be left linked out.
2.5 BMS Connections Terminal connections are available on the circuit board for
connections to Building Management systems etc. Detailed on the circuit board as [BMS OUT
N/C, Com and N/O] these are volt free connections.
2.6 Remote emergency shut off buttons. The terminal for remote emergency shut-off buttons
is detailed on the circuit board as [EM REMOTE]. These connections are linked out as a factory
setting. Remote emergency shut-off buttons should be volt free and wired to the Merlin 1500S
using two-core cable.
2.7 Gas Detector The terminals detailed on the circuit board as “Gas Detector”. These
connections are [+ - ] these can be wired to a Merlin gas detector. If no detector is being
used leave the link in between the “ ”.
2.8 FS 123 This terminal switches when the key is turned on and off. This can be linked to a fan
switch (panel supplied separately) which can provide power to the fans when the control panel
is switched on.
2.9 CO2 Monitor This terminal can be wired to CO2 monitor to shut off the system in the event
of CO2 being at alarm level. If no CO2 monitor is supplied leave the terminal link in.
2.10 12v DC This is a permanent 12v DC output when there is power at the panel. This is
normally used to power a PM2 current monitor. (Supplied separately)
2.11 Internal Buzzer Operates at 65dB measured 30cm from closed panel.
Note: all low voltage connections should be made using a screened cable. To avoid electrical interference
this should not be in the same conduit as mains cable as per the low voltage directive.

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 4
3Operation Instructions
3.1 How to turn the system on and off
1. Turn the Fans On.
2. Turn the key switch to on position.
3. To turn the system off, turn the key switch to off position.
3.2 Explanation of LED status
Power LED
When the system is connected to the mains supply, the Red LED of the AGS Logo located in the
bottom right corner of the panel will illuminate. When no power is present, this LED will not light
up.
RED = OK
OFF = No power to 1500S, a loose ribbon connection or the fuse may not be intact.
Gas On LED
When the fans are running at the correct speed and the key switch is turned on, the Merlin 1500S
will open the gas valve and the green ‘Gas On’ LED will illuminate.
GREEN = Gas On
OFF = Gas Off
Supply Fans LED
Under normal working the LED will illuminate GREEN. If a supply fan fault is detected, the LED will
be flashing.
GREEN = OK
FLASHING = One of the supply fans is not running.
Extract Fans LED
Under normal working the LED will illuminate GREEN. If an extract fan fault is detected, the LED
will be flashing.
GREEN = OK
FLASHING = One of the extract fans is not running
IF SUPPLY AND/OR EXTRACT FANS LED FLASHES FOR MORE THAN 20 SECONDS, THE Merlin 1500S
WILL SHUT OFF THE GAS.
Fan Fault LED
Under normal working conditions this LED is off. If a fan fault is present for more than 20 seconds,
the LED will illuminate RED.
OFF = OK
RED = the gas supply has been shut off due to a ventilation fault.
IF A FAULT IS FOUND YOU WILL NEED TO CONTACT YOUR SERVICE/MAINTENANCE COMPANY
YOU SHOULD NOT ATTEMPT TO CARRY OUT A REPAIR UNLESS YOU ARE QUALIFIED TO DO SO.

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 5
EM Stop LED
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.
OFF = OK
AMBER = EM Stop button pressed
Gas Detected LED
Under normal working conditions this LED is off. If the external Merlin detector connected detects
gas this will show RED and the Gas valve will turn off.
OFF = OK
RED = Gas detected.
CO2 High LED
Under normal working conditions this LED is off. If the concentration of CO2 in the air is at
alarm level (relevant detector required), the LED will show RED and the Gas valve will turn off.
OFF = OK
RED = the concentration of CO2 is at alarm level.
3.3 CO2Mode
Under normal working conditions the Merlin 1500S monitors the ventilation and the concentration
level of CO2. In the event of ventilation failure or if the CO2level is at alarm level, the panel will
shut off the gas supply.
The Merlin 1500S features a ‘CO2Mode’ this allows the kitchen to have the access to the gas
supply in the event of a fan failure. There is a ‘CO2Mode’ button located on the front of the
panel. This button will only be available to use when ‘Fan fault’ LED illuminates Red. To enable
the CO2Mode, the ‘CO2button’ has to be pressed for 5 seconds. The Fan Fault LED will go off
and CO2Mode LED will come on. In this mode, the Merlin 1500S will monitor only the CO2levels
to ensure there is a safe working environment. This mode will allow the gas valve to open for 8
hours each time the system is energised, provided there are satisfactory levels of CO2.
At the end of 8 hours, the gas valve will close and CO2 Mode LED will be flashing.
To reinstate the system the panel has to be restarted. The ‘CO2 Mode’ will be permanently
disabled if a CO2 Sensor is not detected at power up.
3.4 Using the Emergency Shut Off
The Emergency shut off button is located on the front of the panel. There is also a facility for
remote shut off buttons to be wired in series.
The Emergency shut off button(s) will cut off the gas supply when activated.
To reinstate the system, the Emergency shut off button(s) will need to be reset and the panel
restarted.

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 6
3.5 BMS integration
The Merlin 1500S 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 100-240VAC is being sent to the
solenoid.
There is a dip-switch located on the inside facia of the Merlin 1500S labelled ‘BMS Selection’. This
is factory set in the ‘off’ position which signals the BMS on gas on/gas off. When switched to the
‘on’ position, the 1500S will only signal the BMS on a gas detected.
3.6 Fire alarm integration
The Merlin 1500S can be integrated with a fire alarm to close the gas supply automatically in the
event of a fire.
The volt free fire alarm signal can be wired in series with any remote emergency shut off buttons.
If there is no remote emergency stop buttons installed wire this directly to the terminal marked
‘EM REMOTE’.
3.7 Fan Switch Integration
There is the facility to connect a Fan Switch (FS1 or FS2 sold separately).
The Fan Switch provides the facility to turn on the fan(s) when the key switch on the Merlin 1500S
is in the on position and turn the power off to the fan(s) when the key switch on the Merlin 1500S
is in the off position.
There is a dip-switch located inside the facia of the Merlin 1500S labelled EM Selection.
This is factory set in the ‘off’ position which instructs the system to shut down the fan(s) and gas
supply on activation of the Emergency shut off button(s). On installation, this can be switched
to the ‘on’ position if required. This will instruct the system to leave the fans on and only shut off
the gas supply on activation of the Emergency shut off button(s). Note: This option is not
available if Fan Switch is not installed.

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 7
1500S Wiring Diagram
1. Mains Input 110-120VAC.
2. Gas Solenoid Valve Power Output, 110-120VAC.
3. Supply Fan 1 and 2 external pressure differential switch or current switch. VOLT FREE INPUT
4. Extract Fan 1 and 2 external pressure differential switch or current switch. VOLT FREE INPUT
5. BMS output contacts. Normally Closed, Common and Normally Open. Max.1A @ 120VAC.
6. Remote EM Stop buttons and Fire Alarm input wired in series (purchased separately). VOLT FREE INPUT
7. Methane, CO or LPG Detector, power supply and VOLT FREE INPUT (purchased separately).
8. Fan Switch output (purchased separately). For wiring instruction see Fan Switch user manual.
9. CO2 Monitor (purchased separately). VOLT FREE INPUT
10. Permanent 12VDC output (Normally used to power a PM2 Current Monitor). 50A Max.
Please note, Mains wires and low voltage wires
should not be run in the same conduit as per the
LOW VOLTAGE DIRECTIVE

Merlin 1500S Gas Interlock System User & Installation Manual
Rev: 03 Date: 08-01-18 8
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.
CONTACT US:
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