Bacharach MGS-450 Operating Manual

1100-2294 Rev 1 1

1100-2294 Rev 1 1

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 specifications. 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 officer of Bacharach.

Register Your Warranty by Visiting: www.mybacharach.com/warranty-registration/

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, filters and batteries have individual warranties). Should your analyzer 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 monitor, prepaid, to the closest service center. Prior to shipping equipment to
Bacharach, visit www.mybacharach.com for a Returned Merchandise Authorization Number (RMA #). 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 specifications 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 © 2019, 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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Table of Contents

Table of Contents 2

1. Introduction 6

1.1 About this Manual 6

1.2 Conventions 6

1.2.1 Short Form Instructions 6

1.2.2 Iconography 6

1.3 General Safety Statements 7

1.4 Safe Connection of Electrical Devices 8

2. Product Descriptions 9

2.1 Intended Uses / Applications 9

2.2 Transmitter Construction 9

2.3 Power Options 9

2.4 Diagnostic / Status LED 10

2.5 Configurable Output Signals 10

2.6 User Interface 10

2.7 Technical Specifications 10

2.8 Components 13

2.8.1 MGS-410 Components 13

2.8.2 MGS-450 Components 14

2.8.3 MGS-460 Components 15

3. Installation 16

3.1 General Information 16

3.2 Restrictions 17

3.3 Mechanical Installation 17

3.4 Electrical Installation 17

3.4.1 Preparations 17

3.4.2 Power & Signal Wiring 18

3.4.3 Relay Wiring 19

3.4.4 Installation of Remote Sensing Head 19

3.4.5 Connecting to MGS-408 Gas Detection Controller 20

3.4.6 Modbus RTU RS-485 Interface 20

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3.4.7 Confirming Instrument Functionality 21

4. Operation 22

4.1 Overview of Normal Operation 22

4.1.1 Applying Power & the Start-up Sequence 22

4.1.2 Verifying Analog Signals 22

4.1.3 Verifying the Modbus Signal 23

4.1.4 Status Indication 24

4.1.5 Switch Functions 24

4.1.6 Reset System to Factory Default Settings 25

4.2 MGS-400 Smartphone Application 26

4.2.1 Enable Bluetooth® Connection 26

4.2.2 Checking Status 26

4.2.3 Instrument Configuration 28

4.2.3.1 Change Alias 28

4.2.3.2 Change Unlock Code 28

4.2.3.3 Change Bluetooth Passcode 28

4.2.3.4 Reset to factory defaults 29

4.2.3.5 Alarm Configuration 29
Low Alarm Setpoint 29
High alarm Setpoint 30
Alarm Latching 30

4.2.3.6 Modbus Configuration 30
Address 30
Baud Rate 31
Stop Bits 31
Parity 31
Enable 120Ω Termination 31

4.2.3.7 Output Configuration 31
Analog Output Range 31
Buzzer 32
Relay Failsafe 32
Alarm Delay 32
Analog Zero Adjust 32

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Analog Span Range 33

5. Care & Maintenance 34

5.1 Maintenance Intervals 34

5.2 Adjustments 35

5.2.1 Introduction 35

5.2.2 General Calibration Procedure 36

5.2.3 Zero Adjustment 36

5.2.4 Span Adjustment 37

5.2.5 System Bump Test 38

5.3 Troubleshooting 39

5.3.1 Hexadecimal Format 39

5.3.3 Fault Codes 39

5.4 Sensor Maintenance 41

5.4.1 Replacing the Sensor Module 41

5.5 Cleaning the Instrument 42

6. Additional Information 43

6.1 Sensor Principle 43

6.1.1 Electrochemical Sensors 43

6.1.2 Catalytic Bead Sensors 43

6.1.3 Semiconductor Sensors 44

6.1.4 Infrared Sensors 44

6.2 Disposing of the Instrument 45

6.2.1 Disposing of the Electrical & Electronic Equipment 45

6.2.2 Disposing of Sensors 45

6.3 Sensor Specifications 45

6.4 Modbus Registers 46

6.4.1 Integration - Dynamic Sensor Data 46

6.4.2 Integration - Static Sensor Data 47

6.4.3 Integration - General System Setup 48

6.4.4 Integration – Calibration 49

6.4.5 Integration - User Debug Tools 50

6.4.6 MGS Compatibility - Status Flags 50

6.4.7 Integration - Status Flags 50

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6.4.8 MGS Compatibility - Clear Special States 51

6.4.9 Integration - User Tasks 51

7. Ordering Information 52

7.1 Part Numbers 52

7.1.1 MGS-400 Gas Detector Configurations 52

7.1.2 MGS-400 Series Accessories 54

7.2 Service Center Locations 55

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1. Introduction

1.1 About this Manual

Thank you for investing in a Bacharach MGS-400 gas detector. To ensure operator safety and
the proper use of the gas detector, please read the contents of this manual for important
information on the operation and maintenance of the instrument.

1.2 Conventions

1.2.1 Short Form Instructions

This document uses a short form for describing steps (e.g. executing a command).

Example:

Accessing sensor calibration.

Short Form Instructions:

To select access sensor calibration: Home Tab  Calibrate  enter Unlock Code

Steps Required:

1. Open the Home Tab.

2. Select Calibrate.

3. When prompted, enter the Unlock Code to access calibration screen.

1.2.2 Iconography

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.

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1.3 General Safety Statements

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.

DANGER: This instrument is neither certified nor approved for operation in
oxygen-enriched atmospheres. Failure to comply may result in personal injury or
death.

WARNING: Use this product only for the purposes specified in this document and
under the conditions listed.

WARNING: This instrument has not been designed to be intrinsically safe for use
in areas classified as being hazardous locations. For your safety, DO NOT use it in
hazardous (classified) locations.

WARNING: In the event of an alarm or over-range condition, the sensor must be
recalibrated to ensure continued accuracy.

WARNING: This product must be recalibrated if installed in a non-room condition
environment (i.e. temperature or humidity extremes).

WARNING: The gas diffusion path can become occluded (moisture, dust, debris,
frozen condensation) over time resulting in reduced or complete lack of gas

detection and alarming function. Routine visual inspection of the gas detector and
bump testing are suggested to ensure proper gas detection and alarm function.

CAUTION: Except for maintenance detailed in this manual, these products should
only be opened and / or serviced by authorized Bacharach personnel. Failure to
comply may void the warrant.

CAUTION: Operator assumes responsibility for complying with all laws, rules and
regulations governing the use of this product.

CAUTION: Use only genuine Bacharach parts and accessories. Failure to comply
may impair the operation of the product and / or void the warranty.

CAUTION: Only operate the product within the framework of a risk-based alarm
signaling concept.

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1.4 Safe Connection of Electrical Devices

WARNING: Before connecting this instrument to electrical devices not mentioned
in this manual, consult the manufacturer or a qualified professional. Failure to
comply may result in injury and / or damage to the product.

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2. Product Descriptions

2.1 Intended Uses / Applications

MGS-400 gas detectors are to be installed in non-classified, non-hazardous, permanent
locations for the purpose of continuously monitoring ambient air (indoor or outdoor) for the
following gas types:

• Refrigerants

• Oxygen

• Toxic and combustible gases

WARNING: This instrument is neither certified nor approved for operation in
oxygen-enriched atmospheres. Failure to comply may result in EXPLOSION.

WARNING: This instrument has not been designed to be intrinsically safe for use
in areas classified as being hazardous locations. For your safety, DO NOT use it
in hazardous (classified) locations.

2.2 Transmitter Construction

MGS-400 gas detectors may be purchased in the following configurations:

MGS-410

MGS-450

MGS-450

MGS-460

Enclosure

IP66

IP41

IP66

IP66

Relays

- 3 3

3

Communication

Modbus

Modbus

Modbus

Modbus

Output

-

Analog

Analog

Analog

Sensor

Integrated

Integrated

Integrated

Remote

2.3 Power Options

MGS-400 gas detectors may use the following power options:

• 24 VAC

• 19.5 to 28.5 VDC

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2.4 Diagnostic / Status LED

MGS-400 gas detectors feature a three-color LED (green, orange and red) which are used, in
combination with an audible alarm, to communicate the status of the instrument.

2.5 Configurable Output Signals

MGS-400 gas detectors may be connected to a Bacharach’s MGS-408 Gas Detection Controller
or a third-party device capable of accepting digital and/or analog outputs from the gas detectors,
such as a Building Management System (BMS) or Programmable Logic Controller (PLC). With
the integrated audio-visual alarm indication, an instrument can be operated as a stand-alone
unit (with additional local alarm signaling as required). Configurable output signal options
include the following:

 MGS-410, MGS-450, MGS-460 – Digital Output (Modbus RTU signal)
 MGS-450, MGS-460 – 3× Relays (high alarm / low alarm / fault)
 MGS-450, MGS-460 – 1× Analog Output (4 to 20 mA, 0 to 5 V, 0 to 10 V, 1 to 5 V,

2 to 10 V)

2.6 User Interface

MGS-400 gas detectors allow users to interface directly with the instrument via the following:

 Bluetooth® Communication (MGS-400 App allows users to configure the gas

detector, initiate calibration, bump test / functional test modes and view status
information.)

 Tactile / Magnetic Switches (A non-intrusive magnetic wand allows users to

initiate calibration of the device.)

2.7 Technical Specifications

Category

Specifications

Signals to

Central

Controller

Analog Current

Normal operation:............................................. 4 to 20 mA

Drift below zero:..................................................... 3.8 mA

Measuring range exceeded:................................. 20.5 mA

Instrument fault:.................................................. ≤ 1.2 mA

Fault on analog interface:.................................... > 21 mA

Offline mode/Maintenance signal:....... 3 mA steady signal

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Signals to

Central

Controller

Analog Voltage

0 to 5V; 1 to 5V; 0 to 10V; 2 to 10V (selectable). During
fault condition, 1 to 5V and 2 to 10V outputs are 0V.

Modbus RTU over
RS-485

Baud rate:............................. 9,600 or 19,200 (selectable)

Start bits:......................................................................... 1

Data bits:......................................................................... 8

Parity:.................................. None, odd, even (selectable)

Stop bits:............................................... 1 or 2 (selectable)

Retry time:.................... 500 ms, min time between retries

End of message:............................... Silent 3.5 characters

Power Supply

and Relays

Operating Voltage

19.5 to 28.5 VDC; 24 VAC ± 20%, 50/60 Hz

Inrush Current

1.5 A

Operating Current,
Max.

MGS-410: 2W, 85mA @ 24VDC
MGS-450/60: 4W, 170mA @ 24VDC

Relay Rating

3 SPDT
1A at 30 VAC/VDC, resistive load

Audible Alarm

Internal Buzzer ≥72 dB at 4”

(10 cm)

Alarm Delay

0 to 15 minutes (selectable)

Wiring

Power and Analog
Signal

2-core shielded cable, 16 to 20 AWG (0.5 to 1.5 mm2)

Modbus Network

3-core, 2 twisted pair + ground, shielded cable with 120 Ω
characteristic impedance, 16 to 24 AWG (0.2 to 1.5
mm2).

Cable Gland

M20, 10-14mm cable outer diameter
M16, 4-8mm cable outer diameter

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Physical

Specifications

Enclosure
Protection

IP41 / IP66

Enclosure Size
(W×H×D) (Approx.)

MGS-410: 5.1×5.1×2.7” (130×130×68 mm)
MGS-450 IP41: 6.5× 6.5×3.0” (165×165×77 mm)
MGS-450 IP66: 6.5×6.5×3.4” (165×165×87 mm)
MGS-460: 6.5×6.5×3.4” (165×165×87 mm)

MGS-460 Remote: 4.5× 5.4×2.7” (115×136×68 mm)

Weight (Approx.)

MGS-410: 9.2oz

(260 g)

MGS-450: 1lb, 1oz

(480 g)

MGS-460: 1lb, 11.7oz

(758 g)

Environmental

Temperature

- 40 to 120 ºF (-40 to 50 ºC)

Storage
Temperature

- 5 to 100 ºF (-20 to 40 ºC)

Humidity

5 to 90 %RH, non-condensing

(15 to 90 %RH, non-condensing, EC sensors excl. O2)

Pressure

23.6 to 32.5 inch Hg / 800 to 1,100 mbar

Elevation

0 to 10,000 ft. (3,050 m) altitude

Sensors

See Section 6.3 for sensor specifications.

Influences

For influences on the measurement performance and
restrictions of a particular sensor see sensor data sheet.

Agency

Approvals

CE, EN 50270:2015, UL/CSA/IEC/EN 61010-1

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2.8 Components

CAUTION: This product uses semiconductors which can be damaged by
electrostatic discharge (ESD). When handling the printed circuit boards (PCBs),
observe proper ESD precautions so that the electronics are not damaged.

2.8.1 MGS-410 Components

#

Component Description

#

Component Description

1

M16 Cable Glands (×4)

7

Ribbon Cable Connection (To Sensor)

2

Rubber Gasket

8

Power Connection (In)

3

Digital Connection / Modbus (In)

9

Internal Alarm Buzzer

4

Digital Connection / Modbus (Out)

10

Power Connection (Out)

5

Tactile Switch #1

11

Magnetic Switch #1

6

Tactile Switch #2

12

Magnetic Switch #2

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2.8.2 MGS-450 Components

#

Component Description

#

Component Description

1

M16 Cable Glands (×6)

9

Tactile Switch #2

2

Rubber Gasket (IP66 Version Only)

10

Relay 3 Connection (FAULT)

3

Internal Alarm Buzzer

11

Relay 2 Connection (HIGH)

4

Power Connections (×2)

12

Relay 1 Connection (LOW)

5

Digital Connection (Modbus)

13

Magnetic Switch #1

6

Analog Connection

14

Magnetic Switch #2

7

Tactile Switch #1

15

M20 Cable Glands (×2)

8

Ribbon Cable Connection (To Sensor)

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2.8.3 MGS-460 Components

#

Component Description

#

Component Description

1

M16 Cable Glands (×6)

9

Tactile Switch #2

2

Rubber Gasket (×2)

10

Relay 3 Connection (FAULT)

3

Internal Alarm Buzzer

11

Relay 2 Connection (HIGH)

4

Power Connections (×2)

12

Relay 1 Connection (LOW)

5

Digital Connection (Modbus)

13

Magnetic Switch #1

6

Analog Connection

14

Magnetic Switch #2

7

Tactile Switch #1

15

M20 Cable Glands (×3)

8

RJ45 Connects (×2)

16

Ribbon Cable Connection (To Sensor)

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3. Installation

IMPORTANT: The manufacturer of this product requires that a bump test or
calibration be performed following installation to verify instrument functionality.

3.1 General Information

Installation site selection is critical to ensuring system performance and effectiveness. Strict
compliance and considerable thought must be given to every detail of the installation process,
including, but not limited to the following:

● Regulations as well as local, state, and national codes that govern the installation of gas
monitoring equipment

● Electrical codes that govern the routing and connection of electrical power and signal
cables to gas monitoring equipment

● The full range of environmental conditions to which the instruments will be exposed

● The physical characteristics of the gas or vapor to be detected

● The specifics of the application (e.g., possible leaks, air movement/draft, etc.)

● The degree of accessibility required for maintenance purposes

● The types of optional equipment and accessories that will be used with the system

● Any limiting factors or regulations that would affect system performance or installations

● Wiring details, including:

MGS-410

MGS-450

MGS-460

M16 Cable Glands

(4-8mm cable diameter)

4

6

6

M20 Cable Glands

(10-14mm cable diameter)

-

2

1

● Secondary circuit must be supplied from an isolating source

● The wiring for the relays must be selected and fused according to the rated voltages,

currents, and environmental conditions

● If stranded conductors are used, a ferrule should be used

● To comply with RFI immunity regulations, it is necessary to ground the shield of the

communications cable at the PLC, GDA controller, front-end controller, or Building
Management System (e.g., the chassis, the ground bus-bar, etc.).