Bacharach MGS-402 User manual

Fixed Gas Detection
P/N: 1100-2570 | March 2020 Revision 1
MGS-402 Gas Detection Controller
for Commercial & Industrial Applications
User
Manual

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MGS-402 User Manual
WARRANTY POLICY
Bacharach, Inc. warrants to buyer that at the time of delivery this product will be free from defects in material and
manufacture and will conform substantially to Bacharach, Inc.’s applicable specications. Bacharach’s liability and
buyer’s remedy under this warranty are limited to the repair or replacement, at Bacharach’s option, of this product or
parts thereof returned to seller at the factory of manufacture and shown to Bacharach, Inc.’s reasonable satisfaction
to have been defective; provided that written notice of the defect shall have been given by buyer to Bacharach, Inc.
within one (1) year after the date of delivery of this product by Bacharach, Inc.
Bacharach, Inc. warrants to buyer that it will convey good title to this product. Bacharach’s liability and buyer’s remedy
under this warranty of title are limited to the removal of any title defects or, at the election of Bacharach, to the
replacement of this product or parts thereof that are defective in title.
THE FOREGOING WARRANTIES ARE EXCLUSIVE AND ARE GIVEN AND ACCEPTED IN LIEU OF (I) ANY AND ALL
OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE: AND (II) ANY OBLIGATION, LIABILITY, RIGHT, CLAIM
OR REMEDY IN CONTRACT OR TORT, WHETHER OR NOT ARISING FROM BACHARACH’S NEGLIGENCE, ACTUAL OR
IMPLIED. The remedies of the buyer shall be limited to those provided herein to the exclusion of any and all other
remedies including, without limitation incidental or consequential damages. No agreement varying or extending the
foregoing warranties, remedies or this limitation will be binding upon Bacharach, Inc. unless in writing, signed by a
duly authorized ocer of Bacharach.
Register Your Warranty by Visiting: www.mybacharach.com
SERVICE POLICY
Bacharach, Inc. maintains a service facility at the factory. Some Bacharach distributors / agents may also have repair
facilities; however, Bacharach assumes no liability for service performed by anyone other than Bacharach personnel.
Repairs are warranted for 90-days after date of shipment (sensors, pumps, lters and batteries have individual
warranties). Should your instrument require non-warranty repair, you may contact the distributor from whom it was
purchased or you may contact Bacharach directly.
If Bacharach is to do the repair work, send the instrument, prepaid, to the closest service center. Prior to shipping
equipment to Bacharach, visit www.mybacharach.com for a Returned Merchandise Authorization Number ( #). All
returned goods must be accompanied by a RMA #. Pack the equipment securely (in its original packing, if possible),
as Bacharach cannot be held responsible for any damage incurred during shipping to our facility. Always include
your RMA #, shipping address, telephone number, contact name, billing information and a description of the defect
as you perceive it. You will be contacted with a cost estimate for expected repairs prior to the performance of any
service work. For liability reasons, Bacharach has a policy of performing all needed repairs to restore the monitor to
full operating condition.
NOTICES
Product improvements and enhancements are on-going, therefore the specications and information contained in
this document may change without notice.
Bacharach, Inc. shall not be liable for errors contained herein or for incidental or consequential damages in connection
with the furnishing, performance, or use of this material.
No part of this document may be photocopied, reproduced, or translated to another language without the prior
written consent of Bacharach, Inc.
Copyright © 2020, Bacharach, Inc., All Rights Reserved.
BACHARACH is a registered trademark of Bacharach, Inc. All other trademarks, trade names, service marks and logos referenced herein belong to
their respective companies.

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Contents
Introduction ..................................................... 1
1.1 About this Manual ........................................................................................................... 1
1.2 Conventions...................................................................................................................... 1
1.2.1 Iconography..................................................................................................................................................1
1.3 General Safety Statements............................................................................................. 2
Product Description......................................... 3
2.1 Product Overview ............................................................................................................ 3
2.2 Intended Use .................................................................................................................... 4
2.3 Design Features ............................................................................................................... 4
2.4 Front Panel ....................................................................................................................... 5
2.5 Components ..................................................................................................................... 6
2.6 Communication Features ............................................................................................... 6
Installation ....................................................... 7
3.1 Warnings & Cautions ....................................................................................................... 7
3.2 Preliminary Inspection.................................................................................................... 7
3.3 Suitable / Appropriate Locations ................................................................................... 7
3.4 Mounting the Gas Detection Controller........................................................................ 8
3.5 Power Wiring .................................................................................................................... 8
3.5.1 Connecting the Main (100-240 VAC) Power...............................................................................................8
3.6 Sensor Output & Modbus Connections......................................................................... 9
3.6.1 MGS-402 Gas Detection Controller Network.............................................................................................9
3.6.2 Integration with Building Management System .....................................................................................11
3.7 Connecting External Alarms ......................................................................................... 11
3.7.1 Overview......................................................................................................................................................11
3.8 Reinstalling MGS-402 Lid............................................................................................... 12

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Operation........................................................ 14
4.1 Overview ......................................................................................................................... 14
4.1.1 Main Function.............................................................................................................................................14
4.1.2 Power Up.....................................................................................................................................................14
4.1.3 Channel number keys................................................................................................................................14
4.2 Controller Setup............................................................................................................. 14
4.2.1 Modbus Setup.............................................................................................................................................14
4.2.2 Relay Setup .................................................................................................................................................16
4.3 Gas Detection System Test ........................................................................................... 17
Modbus............................................................ 19
5.1 Modbus Overview.......................................................................................................... 19
5.1.1 SLAVE NODE ADDRESS ...............................................................................................................................19
5.1.2 SLAVE BAUD RATE.......................................................................................................................................19
5.1.3 SLAVE PARITY .............................................................................................................................................19
5.1.4 SLAVE STOP BIT...........................................................................................................................................19
5.1.5 SLAVE TERMINATION .................................................................................................................................19
5.2 Modbus Registers .......................................................................................................... 19
Diagnostics & Troubleshooting .................... 24
6.1 FAULT CODES.................................................................................................................. 24
Additional Information ................................. 25
7.1 Disposing of Instrument ............................................................................................... 25
7.2 TechnicalSpecications................................................................................................ 25
Parts and Accessories.................................... 26
8.1 Part Numbers................................................................................................................. 26
8.2 Service Center Locations............................................................................................... 26

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Alert Icon Description
DANGER Imminently hazardous situation which, if not avoided, will result in death or
serious injury.
WARNING Potentially hazardous situation which, if not avoided, could result in death or
serious injury.
WARNING Potential electrical shock hazard which, if not avoided, could result in death
or serious injury.
CAUTION
Potentially hazardous situation which, if not avoided, could result in physical
injury or damage to the product or environment. It may also be used to alert
against unsafe practices.
IMPORTANT Additional information on how to use the product.
IMPORTANT:Before using this product, carefully read and strictly follow the instructions in the
manual. Ensure that all product documentation is retained and available to anyone operating
the instrument.
1. Introduction
1.1 About this Manual
Thank you for investing in a Bacharach MGS-402 Gas Detector Controller. To ensure operator safety and
the proper use of the controller, please read the contents of this manual for important information on the
operation and maintenance of the instrument.
1.2 Conventions
1.2.1 Iconography

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1.3 General Safety Statements
DANGER:This instrument is neither certied nor approved for operation in oxygen-enriched atmospheres
and / or hazardous locations. Failure to comply may result in personal injury or death.
CAUTION: The protection provided by this product may become impaired if it is used in a manner
not specified by the manufacturer. Modifications to this instrument, not expressly approved, will
void the warranty.
CAUTION: In case of malfunction, DO NOT continue to use this equipment if there are any symptoms of
malfunction or failure. In the case of such occurrence, de-energize the power supply and contact a qualied
repair technician or the nearest Bacharach Service Center.
CAUTION: Use ONLY the provided cable glands for electrical and communication wiring. Drilling into the
box will void the warranty.
WARNING: Always remove AC power before working inside the MGS-402 enclosure and exercise extreme
care when accessing the products interior. Only qualied electrical maintenance personnel should perform
connections and adjustments.

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2. Product Description
2.1 Product Overview
The MGS-402 Gas Detection Controller displays centralized information about the status of connected MGS-
410 gas detectors. The MGS-402 is connected to the MGS-410s via Modbus RTU.
The MGS-402 can be used to provide power to each connected MGS-410 gas detector, negating the need for
separate power supply at the location of the gas detector.
The MGS-402 displays status via a bank of LEDs that represent the channel/sensor connected to it. Each
channel/sensor has a row of dedicated LEDs to indicate the status of the sensor:
Power  Fault Low alarm  High alarm
The MGS-402 provides three relays (fault, low and high alarm status) for connection to auxiliary systems,
ventilation or other equipment.
The MGS-402 has an integrated visual alarm of LEDs around the perimeter of the controller that will activate
when a low or high alarm is received from either channel. In addition, the integrated audible alarm will
activate in the same manner.
In addition to being a Modbus master to the MGS-410 gas sensors, the MGS-402 acts as a Modbus slave
for ease of integration into a building automation system (BMS) or programmable logic controller (PLC). The
controller also features two analog outputs which may enable monitoring gas detector levels remotely.
Figure 2-1 - The MGS-402 Gas Controller System

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WARNING: This instrument is neither certied nor approved for operation in oxygen-enriched
atmospheres. Failure to comply may result in EXPLOSION.
WARNING: For your safety, DO NOT use this instrument in locations classied as hazardous
because it has not been designed for such areas.
2.2 Intended Use
The MGS-402 provides audio-visual alerts and information pertaining to the status of a centralized gas
detector network. This information allows concise, at-a-glance notication of any alarm or fault status
regarding a connected gas detector located outside the monitored space, as required by industry safety
standards (EN 378, ASHRAE 15).
2.3 Design Features
Power options 100 - 240 VAC, 50/60 Hz, 20 W (max.)
Provides power for up to (2) MGS-410 Bacharach gas detectors
Output/
Communications
RS485 Modbus RTU Master for Gas Detectors
RS485 Modbus RTU Slave for BMS
Diagnostic/status LEDs
• Controller (power, fault)
• Gas detectors (power, fault, low alarm, high alarm)
Congurable output options
• 3 × relays (fault, low alarm, high alarm)
• 2× Analog outputs (4-20 mA, 1-5 V or 2-10 V)
Integrated high output visual strobe
Integrated high output audible alarm
Remote silence input (In addition to silence on the on the controller input.)

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2.4 Front Panel
Figure 2-2 - Front Panel Layout
# Front Panel Description
1 Integrated visual alarm in bezel
2 Controller Power & Fault LEDS
3 Channel 1 and 2 mute alarm buttons
4 Power, Fault, Low Alarm, High Alarm LEDs; each channel
5 M16 Cable Glands (×6)
6 M20 Cable Glands (×2)

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2.5 Components
Figure 2-3 - MGS-402 Layout
# Component Description # Component Description
1 Analog Outputs (×2) 8 Low Alarm Relay
2 Modbus to Gas Detectors 9 AC Power Line Input
3 Modbus to BMS 10 Power Supply
4 Remote Silence 11 Sensor Power Connections (×2)
5 Audible Alarm 12 M20 Cable Glands (×2)
6 Fault Relay 13 M16 Cable Glands (×6)
7 High Alarm Relay
2.6 Communication Features
The MGS-402 Gas Detection Controller features full two-way communications via an RS-485 interface.
Modbus RTU is the communication protocol standard.
The controller is congured as a Modbus master and can be the centralized controller for a two sensor gas
network and also has a Modbus slave port for connection to a BMS / re safety panel for a complete gas
detection solution.