Factory Set Condition; Quick Installation Tips - S&S Northern MERLIN CO DETECTOR X Installation Operation & Maintenance

Installation, Operation & Maintenance Manual

Factory Set Condition

Buzzer On/Off Switch
Chain Termination Resistor
Detector ID Switches

Quick Installation Tips

CONNECTION
The best way to connect devices in a MODBUS RTU communication is a DAISY CHAIN method.
MAXIMUM DISTANCE
You may encounter problems when powering gas sensors beyond 100 metres from one control panel, in
this instance, contact your supplier.
TERMINAL RESISTANCE
Signal communication issues may occur where the bus length is too long, high baud rates are used or
signal reflections are occurring. To avoid this, terminating at each end of a chain may help the quality of
the data signal by turning on the 120ohm terminal resistor switch of the last device in the chain.
GROUNDING
If you are encountering noise or irregular or abnormal problems, the problem is likely related to
grounding, incorrect shielding or wiring mains power next to Modbus wiring. If using a shielded cable –
ensure the shielding or equivalent is wired to the 24vdc Power [-] terminal on both detectors and panels.
CABLES TO USE
For MODBUS communications, a shielded and twisted pair cable is used. The shielding can be of 2 types:
braided [like a mesh of thin conducting wires] or like a foil [consisting of a thin sheet of metal covering the
twisted wires].
PROTECTION
High concentrations of alcohol found in many products may damage, deteriorate or affect the gas sensing
elements of Detectors – such as; wine; deodorants; stain removers; thinners etc.
IDENTIFICATION
Remember to individually ID each connected detector by configuring the ID switches on the circuit board.
Make a plan, map and/or note of the location of all connected detectors for tracing and locality purposes.
BUZZER ALARM
There are no provisions to silence the alarm buzzer when high gas levels are detected. Gas levels must
return to safe level for the buzzer to stop. The audible buzzer is optional via a switch on the circuit board.
COMMISSIONING
We recommend all Merlin gas detection equipment is commissioned by competent/trained engineers to
ensure correct installation and operation. The Merlin range of gas detectors are optimum calibrated when
manufactured. However, we strongly recommend the detectors response and fault conditions are tested
and validated once installed. This will ensure the equipment is performing as intended and free from
unforeseen damage caused by transit/installation.
DETX-IOM Iss: 7 02-21
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OFF
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Merlin Gas Detector-X
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