Bacharach MGS-150 User manual

Gas Detector
Installation and Operation Manual
Instruction 6309-9000
Revision 2 – February 2013
Product Leadership •Training •Service •Reliability

MGS-150 Manual
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WARRANTY POLICY
BACHARACH, INC. WARRANTS THIS INSTRUMENT, EXCLUDING SENSORS, TO BE
FREE FROM DEFECTS IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF TWO
YEARS FROM THE DATE OF PURCHASE BY THE ORIGINAL OWNER. THE SENSORS
HAVE A WARRANTY PERIOD OF ONE YEAR FROM THE DATE OF PURCHASE. IF
THE PRODUCT SHOULD BECOME DEFECTIVE WITHIN THIS WARRANTY PERIOD,
WE WILL REPAIR OR REPLACE IT AT OUR DISCRETION.
THE WARRANTY STATUS MAY BE AFFECTED IF THE INSTRUMENT HAS NOT BEEN
USED AND MAINTAINED PER THE INSTRUCTIONS IN THIS MANUAL OR HAS BEEN
ABUSED, DAMAGED, OR MODIFIED IN ANY WAY. THIS INSTRUMENT IS ONLY TO BE
USED FOR PURPOSES STATED HEREIN. THE MANUFACTURER IS NOT LIABLE FOR
AUXILIARY INTERFACED EQUIPMENT OR CONSEQUENTIAL DAMAGE.
DUE TO ONGOING RESEARCH, DEVELOPMENT, AND PRODUCT TESTING, THE
MANUFACTURER RESERVES THE RIGHT TO CHANGE SPECIFICATIONS WITHOUT
NOTICE. THE INFORMATION CONTAINED HEREIN IS BASED ON DATA CONSIDERED
ACCURATE. HOWEVER, NO WARRANTY IS EXPRESSED OR IMPLIED REGARDING
THE ACCURACY OF THIS DATA.
ALL GOODS MUST BE SHIPPED TO THE MANUFACTURER BY PREPAID FREIGHT.
ALL RETURNED GOODS MUST BE PRE-AUTHORIZED BY OBTAINING A RETURN
MERCHANDISE AUTHORIZATION (RMA) NUMBER. CONTACT THE MANUFACTURER
FOR A NUMBER AND PROCEDURES REQUIRED FOR PRODUCT TRANSPORT.
SERVICE POLICY
BACHARACH, INC. MAINTAINS AN INSTRUMENT 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 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 BACHARACH, INC. AT THE FOLLOWING ADDRESS.
BACHARACH, INC.
621 HUNT VALLEY CIRCLE
NEW KENSINGTON, PA 15068
ATTENTION: SERVICE DEPARTMENT
ALWAYS INCLUDE YOUR RMA #, ADDRESS, TELEPHONE NUMBER, CONTACT
NAME, SHIPPING/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

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PERFORMING ALL NEEDED REPAIRS TO RESTORE THE INSTRUMENT TO
FULL OPERATING CONDITION.
PRIOR TO SHIPPING EQUIPMENT TO BACHARACH, CONTACT OUR OFFICE
FOR AN RMA # (RETURNED MERCHANDISE AUTHORIZATION). ALL RETURNED
GOODS MUST BE ACCOMPANIED WITH AN RMA NUMBER.
PACK THE EQUIPMENT WELL (IN ITS ORIGINAL PACKING IF POSSIBLE), AS
BACHARACH CANNOT BE HELD RESPONSIBLE FOR ANY DAMAGE INCURRED
DURING SHIPPING TO OUR FACILITY.
NOTICES
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RIGHTS ARE RESERVED UNDER INTERNATIONAL AND DOMESTIC
COPYRIGHT LAWS. THIS MANUAL MAY NOT BE COPIED OR TRANSLATED, IN
WHOLE OR IN PART, IN ANY MANNER OR FORMAT, WITHOUT THE WRITTEN
PERMISSION OF BACHARACH, INC.
ALL SOFTWARE UTILIZED AND/OR DISTRIBUTED BY BACHARACH IS SUBJECT
TO COPYRIGHT PROTECTION. ALL RIGHTS ARE RESERVED. NO PARTY MAY
USE OR COPY SUCH SOFTWARE IN ANY MANNER OR FORMAT, EXCEPT TO
THE EXTENT THAT BACHARACH GRANTS THEM A LICENSE TO DO SO. IF THIS
SOFTWARE IS BEING LOADED ONTO MORE THAN ONE COMPUTER, EXTRA
SOFTWARE LICENSES MUST BE PURCHASED.
TECHNICIAN USE ONLY
THIS UNIT MUST BE INSTALLED BY A SUITABLY QUALIFIED TECHNICIAN WHO
WILL INSTALL THIS UNIT IN ACCORDANCE WITH THESE INSTRUCTIONS AND
THE STANDARDS IN THEIR PARTICULAR INDUSTRY/COUNTRY. OPERATORS
OF THE UNIT SHOULD BE AWARE OF THE REGULATIONS AND STANDARDS IN
THEIR INDUSTRY/COUNTRY FOR THE OPERATION OF THIS UNIT. THESE
NOTES ARE ONLY INTENDED AS A GUIDE AND THE MANUFACTURER BEARS
NO RESPONSIBILITY FOR THE INSTALLATION OR OPERATION OF THIS UNIT.
FAILURE TO INSTALL AND OPERATE THE UNIT IN ACCORDANCE WITH THESE
INSTRUCTIONS AND WITH INDUSTRY GUIDELINES MAY CAUSE SERIOUS
INJURY INCLUDING DEATH AND THE MANUFACTURER WILL NOT BE HELD
RESPONSIBLE IN THIS REGARD.

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Table of Contents
Section 1. Overview .................................................................................... 5
1.1. General Information..................................................................................... 5
1.2. Technical Specifications ............................................................................... 6
Section 2. Installation and Wiring................................................................ 8
2.1. General Placement Guidelines..................................................................... 9
2.2. Components and Access Overview .............................................................. 9
2.3. Machinery Rooms ...................................................................................... 12
2.4. Refrigerated Spaces ................................................................................... 14
2.5. Chillers........................................................................................................ 14
2.6. Air Conditioning (Direct Systems VRF/VRV) ............................................... 15
2.7. Remote Sensor Head Installation............................................................... 16
Section 3. Housing Dimensions ................................................................. 17
Section 4. Operation and Stabilization ...................................................... 21
Section 5. Configurations .......................................................................... 22
5.1. Overview .................................................................................................... 22
5.2. Adjusting the Alarm Set Point .................................................................... 22
Section 6. Functional Tests and Calibration ............................................... 23
6.1. Introduction ............................................................................................... 23
6.2. Bump Testing ............................................................................................. 25
6.3. Calibration Overview.................................................................................. 28
6.4. Calculating Calibration Voltage .................................................................. 29
6.5. Calibrating Semiconductor (SC) Sensors .................................................... 29
6.6. Calibrating Electrochemical (EC) Sensors................................................... 30
6.7. Calibrating Infrared (IR) Sensors ................................................................ 30
Section 7. Troubleshooting........................................................................ 31
CE Declaration of Conformity ........................................................................ 32

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Section 1. Overview
1.1. General Information
The MGS-150 is a state-of-the-art fixed gas detector which can detect a
wide range of different gases. The gas sensors can be used on a stand-
alone basis or integrated into Controls or Building Management Systems
(BMS).
The MGS-150 can be used:
•in new buildings/areas that require continuous monitoring with
high tech gas sensor transmitters.
•to add gas detection solutions to an existing system.
Typical detection applications include the detection of:
•refrigerant gases
•combustible gases
•toxic gases and/or volatile organic compounds.
The MGS Controller is an optional device used to remotely monitor up to
six MGS-150 devices. For more information, refer to the MGS Controller
manual (P/N 6709-9000).
Figure 1. MGS-150 Sensors

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1.2. Technical Specifications
Specification Description
Power Supply
12-24 VDC, 12-24 VAC 50/60 Hz, 2 W max.
Power Monitoring Green LED
Visual Alarm
Red LED
Audible Alarm Buzzer, enable/disable
Fault Monitoring
Red LED (on); Green LED (off)
Analog Outputs 4-20 mA; 0-5 V; 0-10 V; 1-5 V; 2-10 V
Relay
1 relay rated 1 A @ 24 VAC/VDC
Alarm Delay Selectable; 0, 1, 5, or 10 minutes
IP Rating
IP41 (standard); IP66 (optional)
Temperature Rating Housing: Standard IP66
IR Halogen: -4°to 122°F -4°to 122°F
-20°to 50°C -20°to 50°C
IR CO2:-4°to 122°F -40°to 122°F
-20°to 50°C -40°to 50°C
SC (all): -4°to 122°F -40°to 122°F
-20
°
to 50
°
C -40
°
to 50
°
C
Dimensions/Weights per
Enclosure Type (see Note
below)
IP41 3.35” x 5.59” x 2.09”
86 x 142 x 53 mm
6.3 oz
180 g
IP66 6.89” x 6.5” x 3.29”
175 x 165 x 82 mm
1 lb 6 oz
629 g
IP66 w/ Splash
Guard
6.89” x 8.9” x 3.29”
175 x 225 x 82 mm
1 lb 9 oz
700 g
IP66 w/
Remote Sensor
6.89” x 6.1” x 3.29”
175 x 155 x 82 mm
1 lb 11 oz
790 g
IP66 w/ EXd
Sensor Head
6.89” x 6.1” x 3.29”
175 x 155 x 82 mm
2 lb 10 oz
1185 g
IP66 w/PRV
sensor head
6.89” x 6.1” x 3.29”
175 x 155 x 82 mm
2 lb 0.3 oz
916 g
IP66
Airflow/Duct
6.89” x 4.9” x 3.29”
175 x 125 x 82 mm
1 lb 4 oz
578 g
EXd (ATEX
only)
5.12” x 6.3” x 3.54”
130 x 160 x 90 mm
9 lb 4 oz
4200 g
Approvals
CE; UL/CSA/IEC/EN 61010-1
NOTE: Enclosures listed above are for all models/
configurations except IR Halogen, which use the standard IP41
enclosure with a different temperature rating.

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NOTE: The hazardous area EXd Gas Monitor products are
designed with individually certified EXd main housing
enclosures and certified EXD remote or attached sensor
enclosures. The main housing enclosure and its PCB
assembly are also EXd certified, but the final EXd Gas Monitor
assemblies (main enclosure and/or sensor assembly) are not
currently EXD certified, but are pending additional testing.
Supported CFM/Duct Sizes for the Duct Mount Housing
Units Duct Size
Inches 12 x 12 12 x 24 18 x 18 24 x 24 24 round
Feet 1 x 1 1 x 2 1.5 x 1.5 2 x 2 Pi x 1 x 1
Area (ft2) 1 2 2.25 4 3.14
CFM Ft/min (Based on CFM and Duct Size)
2800 2800 n/a n/a n/a n/a
3000 3000 n/a n/a n/a n/a
3400 3400 n/a n/a n/a n/a
3800 3800 n/a n/a n/a n/a
4000 4000 n/a n/a n/a n/a
4400 4400 n/a n/a n/a n/a
4800 4800 n/a n/a n/a n/a
5000 5000 2500 n/a n/a n/a
5400 5400 2700 n/a n/a n/a
5800 5800 2900 2578 n/a n/a
6000 6000 3000 2667 n/a n/a
6400
6400
3200
2844
n/a
n/a
6800
6800
3400
3022
n/a
n/a
7000
7000
3500
3111
n/a
n/a
7400
7400
3700
3289
n/a
n/a
7800
7800
3900
3467
n/a
n/a
8000
8000
4000
3556
n/a
2548
8400
8400
4200
3733
n/a
2675
8800
8800
4400
3911
n/a
2803
9000
9000
4500
4000
n/a
2866
9400
9400
4700
4178
n/a
2994
9800
9800
4900
4356
n/a
3121
10000
10000
5000
4444
2500
3185

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Section 2. Installation and Wiring
WARNING: Explosion hazard! Do not mount the MGS in an
area that may contain flammable liquids, vapors, or aerosols.
Operation of any electrical equipment in such an environment
constitutes a safety hazard.
CAUTION: The MGS contains sensitive electronic components
that can be easily damaged. Do not touch nor disturb any of
these components.
NOTE: The mounting location of the monitor should allow it to
be easily accessible for visual monitoring and servicing.
NOTE: The monitor must be connected by a marked, suitably
located and easily reached switch or circuit-breaker as means
of disconnection.
NOTE: Connect monitor power and signaling terminals using
wiring that complies with local electrical codes or regulations for
the intended application.
NOTE: This instrument can be equipped with a semiconductor
sensor for the detection of refrigerant, combustible and VOC
gases. Semiconductor sensors are not gas specific and
respond to a variety of other gases including propane exhaust,
cleaners, and solvents. Changes in temperature and humidity
may also affect the sensor’s performance.

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2.1. General Placement Guidelines
NOTE: The MGS-150 should be installed plumb and level
and securely fastened to a rigid mounting surface.
Sensors must be located within the appropriate wire lengths from the
central control unit (if used).
In all cases the sensor supplied is designed for maximum sensitivity to a
particular gas. However, in certain circumstances false alarms may be
caused by the occasional presence of sufficiently high concentrations of
other gaseous impurities. Examples of situations where such
abnormalities may arise include the following:
•Plant room maintenance activity involving solvent or paint fumes
or refrigerant leaks.
•Accidental gas migration in fruit ripening/storage facilities
(bananas - ethylene, apples - carbon dioxide).
•Heavy localized exhaust fumes (carbon monoxide, dioxide,
propane) from engine-driven forklifts in confined spaces or close
to sensors.
Bacharach recommends setting the alarm delay to minimize false
alarms.
2.2. Components and Access Overview
NOTE: The wiring is the same for the electro-chemical,
semi-conductor, and infrared models. The controller wiring is
the same for all controllers.
There is a 5-minute power-up delay to allow the sensor to stabilize.
Refer to Figure 2 and Figure 3 for internal components and wiring.

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Figure 2. EC or IR Sensor Components and Wiring

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Figure 3. SC Sensor Components and Wiring

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Item Description
Enclosure
Access To open the standard sensor enclosure, turn the cable
clamp 1/2 turn counter-clockwise to loosen the internal
nut, depress the clip on top of the enclosure and open.
Reverse to close.
Power 12-24V AC/DC, connect at positions 0V and +V at
connector block CN1.
•For AC: Jumper JP1 is on, JP2 is off. (See Figure
2 and Figure 3.
•For DC: Jumper JP1 is off, JP2 is on. (Default
factory setting is DC.)
Use 2 wires, typically 18 AWG (minimum).
Output Connect two wires to terminal block CN2 positions 0V
and V or I for voltage or current, respectively.
•Connect 4-20mA at CN2 positions 0V and I
•Connect voltage output at CN2 positions 0V and V
Relay Set
Point P1 sets the trip point for the relay and audible alarm
using the 0- 5V scale (measure at test points 0V and
alarm test point TP1). Default factory setting is 50% of
the range.
Time
Delay A time delay for the operation of the relay and audible
alarm can be selected using jumpers JP5 and JP6.
Default factory setting is zero.
Audible
Alarm The audible alarm can be disabled using jumper JP3.
Default factory setting is enabled.
2.3. Machinery Rooms
There is no absolute rule in determining the number of sensors and their
locations. However, a number of simple guidelines will help to make a
decision. Sensors monitor a point as opposed to an area. If the gas leak
does not reach the sensor then no alarm will be triggered. Therefore, it
is extremely important to carefully select the sensor location. Also
consider ease of access for maintenance.
The size and nature of the site will help to decide which method is the
most appropriate to use. Locations requiring the most protection in a
machinery or plant room would be around compressors, pressurized
storage vessels, refrigerant cylinders or storage rooms or pipelines. The

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most common leak sources are valves, gauges, flanges, joints (brazed or
mechanical), filling or draining connections, etc.
•When mechanical or natural ventilation is present, mount a
sensor in the airflow.
•In machinery rooms where there is no discernable or strong
airflow then options are:
Point Detection, where sensors are located as near as
possible to the most likely sources of leakage, such as the
compressor, expansion valves, mechanical joints or cable
duct trenches.
Perimeter Detection, where sensors completely surround the
area or equipment.
•For heavier-than-air gases such as halocarbon and
hydrocarbon refrigerants such as R404A, propane, and butane
sensors should be located near ground level.
•For lighter-than-air gas (e.g., ammonia), the sensor needs to
be located above the equipment to be monitored on a bracket or
high on a wall within 12 in (300 mm) of (or on) the ceiling –
provided there is no possibility of a thermal layer trapped under
the ceiling preventing gas from reaching the sensor.
NOTE: At very low temperatures (e.g., refrigerated
cold store), ammonia gas becomes heavier than air.
•With similar density or miscible gases (e.g., CO or CO2), sensors
should be mounted about head high (about 5 ft [1.5 m]).
•Sensors should be positioned just far enough back from any
high-pressure parts to allow gas clouds to form and be detected.
Otherwise, a gas leak might pass by in a high-speed jet and not
be detected by the sensor.
•Make sure that pits, stairwells and trenches are monitored since
they may fill with stagnant pockets of gas.
•If a pressure relief vent (PRV) pipe is fitted to the system, it may
be a requirement to mount a sensor to monitor this vent pipe. It
could be positioned about 6 feet (2 m) above the PRV to allow
gas clouds to form.
•For racks or chillers pre-fitted with refrigerant sensors, these
should be mounted so as to monitor the compressors. If extract
ducts are fitted the airflow in the duct may be monitored.

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2.4. Refrigerated Spaces
In refrigerated spaces, sensors should be located in the return airflow to
the evaporators on a sidewall (below head-high is preferred), or on the
ceiling, not directly in front of an evaporator. In large rooms with multiple
evaporators, sensors should be mounted on the central line between 2
adjacent evaporators, as turbulence will result in airflows mixing.
2.5. Chillers
In the case of small water- or air-cooled enclosed chiller units mount the
sensor so as to monitor airflow to the extract fans. With larger models
also place a sensor inside the enclosure under or adjacent to the
compressors.
In the case of outdoor units:
•For enclosed air-cooled chillers or the outdoor unit for
variable refrigerant volume and variable refrigerant flow (VRV/VRF)
systems, mount the sensor so as to monitor airflow to the extract fan.
With large units also place a sensor inside the enclosure under or
adjacent to the compressors.
In the case of non-enclosed outdoor units:
•If there is an enclosed machinery section locate a sensor there.
•In the case of units with enclosed compressors, mount sensors in the
enclosures.
•Where you have protective or acoustic panels mount the sensor low
down under the compressors where it is protected by the panels.
•With air-cooled chillers or air-cooled condensers with non-enclosed
condenser sections it is difficult to effectively monitor leaks in the coil
sections. With some designs it will be possible using an airflow
sensor to monitor airflow to the start–up fans in the front or rear
sections.
•If there is a possibility of refrigerant leaks into a duct or air-handling
unit install a sensor to monitor the airflow.
Weatherproof sensors should be used for unprotected outdoor
applications.

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2.6. Air Conditioning (Direct Systems VRF/VRV)
For compliance with EN378, at least one detector shall be installed in
each occupied space being considered and the location of detectors
shall be chosen in relation to the refrigerant and they shall be located
where the refrigerant from the leak will collect. In this case refrigerants
are heavier than air and detectors should have their sensors mounted
low, e.g., at less than bed height in the case of an hotel or other similar
Category Class A spaces. Ceilings or other voids if not sealed are part of
the occupied space.
CAUTION: Monitoring ceiling voids in a hotel room would
not strictly comply with EN378.
Do Mount In-Room Sensors… Don’t Mount Sensors…
…at less than the normal heights of the
occupants. E.g., in a hotel room this is less
than bed height (between 8 and 20 inches
[200 and 500 mm] off the floor).
…under mirrors.
…away from drafts and heat sources like
radiators, etc.
…at vanity units.
… to avoid sources of steam. …in or near bathrooms.

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2.7. Remote Sensor Head Installation
If you do not wish to surface mount the MGS, a brushed stainless steel
faceplate is available. The remote sensor is mounted in an electrical
back box 1.7 in (44 mm) deep to which the vented faceplate is fitted.
CAUTION: To avoid component mix-up, do not remove sensor
boards from multiple units at the same time. Alternatively, label
them, or match the serial number on the main PCB and the remote
sensor PCB when reinstalling.
1. Remove the connector from the sensor PCB to feed the cable
through the housing.
2. Immediately refit the connector to the sensor board in the back of the
box. The MGS and remote sensor must be kept together as they are
calibrated together and are a matched pair.
To clean, the faceplate should be lightly dusted.
IMPORTANT: Do not spray the MGS-
150 with cleaning or
polishing aerosols.

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Section 3. Housing Dimensions
Figure 4. MGS-150 Standard Housing

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Figure 5. IP66 Housing with Splashguard

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Figure 6. IP66Airflow Duct Mount Housing
Figure 7. Exd Housing
Units = mm

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For Dimensions and Mounting Locations , See Figure 5.
Figure 8. IP66 Housing with Remote Sensor Head
NOTE: For the Exd Remote Sensor Head and 16.4 ft (5 m) cable,
the thread varies based on the model.
9.8 feet
(3 meters)
Typical