Michell Instruments QMA601 User manual

QMA601
Process Moisture Analyzer
User’s Manual
97449 Issue 3
June 2018

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© 2018 Michell Instruments
This document is the property of Michell Instruments Ltd. and may not be copied or
otherwise reproduced, communicated in any way to third parties, nor stored in any Data
Processing System without the express written authorization of Michell Instruments Ltd.
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QMA601

QMA601 User’s Manual
iv 97449 Issue 3, June 2018
1 INTRODUCTION ................................................................................................1
1.1 General.............................................................................................................. 1
1.2 Theory of Operation ........................................................................................... 2
1.3 Sample Gas Path ................................................................................................ 3
2 INSTALLATION ..................................................................................................4
2.1 Analyzer Storage Instructions.............................................................................. 4
2.2 Unpacking the Analyzer ...................................................................................... 5
2.3 Lifting and Handling ........................................................................................... 5
2.4 Mounting the Analyzer ........................................................................................ 6
2.5 Hazardous Area/Location Safety .......................................................................... 7
2.6 Electrical Safety.................................................................................................. 8
2.6.1 Equipment Ratings and Installation Details...................................................... 8
2.6.2 Power Connection ....................................................................................... 10
2.6.3 Other Electrical Connections ........................................................................ 11
2.7 Pressure Safety ................................................................................................ 12
2.8 Gas Sample Connections................................................................................... 13
3 OPERATION ....................................................................................................15
3.1 General Operational Information........................................................................ 15
3.1.1 First Time Operation.................................................................................... 16
3.1.2 Analyzer Set-Up .......................................................................................... 17
3.2 User Interface .................................................................................................. 18
3.2.1 Interface Controls ....................................................................................... 18
3.2.2 ‘Up/Down Arrow’ Keys................................................................................. 18
3.2.3 'ENTER’ Key................................................................................................ 19
3.2.4 ‘ESC’ Key .................................................................................................... 19
3.2.5 Pop Up Keypad ........................................................................................... 19
3.3 Menu Structure ................................................................................................ 20
3.4 Description of Measured Parameters .................................................................. 21
3.5 Main Screen .................................................................................................... 21
3.5.1 Large Display Mode..................................................................................... 23
3.6 Main Screen Sub Menus.................................................................................... 25
3.6.1 Warning Screen .......................................................................................... 25
3.6.2 Logging Screen ........................................................................................... 26
3.6.3 Alarm Screen .............................................................................................. 27
3.6.4 Field Calibration Screen ............................................................................... 28
3.6.5 Monitor screen............................................................................................ 32
3.7 Settings Menu ................................................................................................. 33
3.7.1 Measurement Screen................................................................................... 33
3.7.2 Outputs Screen ........................................................................................... 38
3.7.3 HMI Screen ................................................................................................ 40
3.7.4 Real Time Clock Screen ............................................................................... 42
3.7.5 Software Communications Screen................................................................. 43
3.7.6 Ethernet Screen .......................................................................................... 43
Contents
Safety .............................................................................................................................. viii
Warnings................................................................................................................... viii
Electrical Safety ......................................................................................................... viii
Pressure Safety.......................................................................................................... viii
Hazardous Materials (WEEE, RoHS2 & REACH)............................................................. viii
Calibration (Factory Validation)......................................................................................ix
Repair and Maintenance ...............................................................................................ix
Abbreviations...................................................................................................................... x

QMA601 User’s Manual
Michell Instruments v
3.7.7 Field Calibration History............................................................................... 44
3.7.8 About Screen.............................................................................................. 44
3.8 Sampling Guidelines ......................................................................................... 46
3.9 Measurement Cycle .......................................................................................... 49
3.10 Calibration Cycle............................................................................................... 51
4 MAINTENANCE ................................................................................................53
4.1 Safety.............................................................................................................. 54
4.2 Removal and Replacement of the Power Supply Fuse .......................................... 54
4.3 Replacing the Optional Contamination Trap ........................................................ 54
4.4 Removal and Replacement of the Desiccant Column............................................ 55
5 CALIBRATION..................................................................................................57
5.1 Traceability ...................................................................................................... 57
6 SHIPPING .......................................................................................................59
6.1 Preparation for Shipping and Packing if Not Supplied as a Sample System ............ 59
7 APPLICATION SOFTWARE OVERVIEW ...............................................................60
7.1 System Requirements ....................................................................................... 60
7.2 System Connection ........................................................................................... 60
7.3 Getting Started................................................................................................. 61
7.3.1 Connection Method (Serial Connection (RS485 or TCP) .................................. 62
7.3.1.1 RS485 Connection................................................................................. 62
7.3.1.2 Modbus TCP Connection (Ethernet) ....................................................... 62
7.4 Main Window ................................................................................................... 63
7.5 Using the Chart ................................................................................................ 64
7.5.1 Chart Options Window................................................................................. 65
7.6 Data Logging ................................................................................................... 66
7.6.1 Configuring Logging Start Time.................................................................... 67
7.6.2 Configuring Logging Stop Time .................................................................... 67
7.6.3 Starting the Log.......................................................................................... 67
7.6.4 Viewing a Log............................................................................................. 67
7.7 Parameters / Field Calibration............................................................................ 67
7.7.1 Field Calibration .......................................................................................... 68

QMA601 User’s Manual
vi 97449 Issue 3, June 2018
Figures
Figure 1 Measurement System .................................................................................3
Figure 2 Mounting Dimensions .................................................................................6
Figure 3 Earthing Stud And Nut Washer Assembly .....................................................9
Figure 4 24 VDC & 240 V AC Power Unit Connectors................................................10
Figure 5 Other Electrical Connections......................................................................11
Figure 6 RJ45 to screw terminal adapter connections ...............................................12
Figure 7 Typical Display .........................................................................................17
Figure 8 User Interface ..........................................................................................18
Figure 9 Up/Down Arrow Keys................................................................................18
Figure 10 ‘ENTER’ Key .............................................................................................19
Figure 11 ‘ESC’ Key .................................................................................................19
Figure 12 Pop Up Keypad.........................................................................................19
Figure 13 Menu Structure ........................................................................................20
Figure 14 Main Screen .............................................................................................21
Figure 15 Large Display Modes.................................................................................23
Figure 16 Full Screen Graph.....................................................................................24
Figure 17 Warning Screen........................................................................................25
Figure 18 Logging Screen ........................................................................................26
Figure 19 Alarm Screen ...........................................................................................27
Figure 21 Field Calibration Screen 2..........................................................................30
Figure 22 Field Calibration Screen 3..........................................................................30
Figure 23 Field Calibration Screen 4..........................................................................31
Figure 24 Field Calibration Screen 5..........................................................................31
Figure 25 Monitor Screen.........................................................................................32
Figure 26 Settings Menu Screen ...............................................................................33
Figure 27 Measurement Screen ................................................................................34
Figure 28 Carrier Gas Screen....................................................................................35
Figure 29 Measurement Screen ................................................................................36
Figure 30 External Options.......................................................................................37
Figure 31 Fixed Options...........................................................................................37
Figure 32 Atmos. Option..........................................................................................37
Figure 33 User Gas Setup Screen .............................................................................38
Figure 34 Outputs Screen ........................................................................................39
Figure 35 HMI Screen..............................................................................................40
Figure 36 Real Time Clock Screen.............................................................................42
Figure 37 Software Communications Screen..............................................................43
Figure 38 Ethernet Screen .......................................................................................43
Figure 39 Calibration History Screen .........................................................................44
Figure 40 About Screen ...........................................................................................45
Figure 42 Measurement Cycle (Phase 2) Calibration Flow ...........................................50
Figure 43 Calibration Cycle (Phase 1) - Dried Sample Flow .........................................51
Figure 44 Calibration Cycle (Phase 2) - Sample Flow ..................................................52
Figure 45 Typical QMA601 Calibration Certificate .......................................................58

QMA601 User’s Manual
Michell Instruments vii
Tables
Table 1 Pop Up Keypad.......................................................................................... 20
Table 2 Main Screen Parameters............................................................................. 23
Table 3 Large Parameter Display Mode ................................................................... 24
Table 4 Warning Screen......................................................................................... 27
Table 5 Logging Screen ......................................................................................... 27
Table 6 Alarm Screen Parameters .......................................................................... 28
Table 7 Calibration Screen Parameters ....................................................................30
Table 8 Monitor Screen Parameters ....................................................................... 33
Table 9 Measurement Screen ................................................................................. 35
Table 10 Outputs Screen Parameters .......................................................................40
Table 11 HMI Setup Screen Parameters ...................................................................42
Table 12 Real Time Clock Screen Parameters ........................................................... 43
Table 13 Software Communications Screen Parameters..............................................44
Table 15 Calibration History Screen .......................................................................... 45
Table 14 Ethernet Screen Parameters ....................................................................... 45
Table 16 Using the Chart ......................................................................................... 65
Table 17 Chart Options............................................................................................ 66
Table 18 Modbus Register Map ................................................................................ 83
Appendices
Appendix A Technical Specification ............................................................................... 71
Appendix B Hazardous Area Certification ...................................................................... 74
B.1 Product Standards ....................................................................... 74
B.2 Product Certification .................................................................... 74
B.3 Global Certificates/Approvals ........................................................ 74
B.4 Special Conditions of Use ............................................................. 74
B.5 Maintenance and Installation........................................................ 75
Appendix C Modbus Holding Register Map .................................................................... 77
C.1 Set Points and Ranges ................................................................. 93
C.2 Gases for Gas Correction Values ................................................... 94
Appendix D Quality, Recycling, Compliance & Warranty Information................................ 96
Appendix E Return Document & Decontamination Declaration........................................ 98
Appendix F Calculating Conversion Factors for Gas Mixes............................................. 100

QMA601 User’s Manual
viii 97449 Issue 3, June 2018
Safety
The analyzer is designed to be completely safe when installed and operated correctly in accordance
with the information provided in this manual.
This manual contains all the required information to install, operate and maintain this product. Prior
to installation and use of this product, this entire manual should be read and understood. Installation
and operation of this product should be carried out by suitably competent personnel only. The
installation and operation of this product must be in accordance with the instructions provided and
according to the terms of any associated safety certificates. Incorrect installation and use of this
product other than those described in this manual and other than its intended purpose will render
all warranties void.
This product meets the essential protection requirements of the relevant EU directives. Further
details of applied directives may be found in the product specification.
Electricity and pressurized gas can be dangerous. This product must be installed and operated only
by suitable trained personnel.
Warnings
!
Where this hazard warning symbol appears in the following sections,
it is used to indicate areas where potentially hazardous operations
need to be carried out and where particular attention to personal and
personnel safety must be observed.
DANGER
Electric
Shock Risk
Where this symbol appears in the following sections it is used to
indicate areas of potential risk of electric shock.
Electrical Safety
Ensure electrical safety is complied with by following the directions provided here and observing all
local operation & installation requirements at the intended location of use.
This product is completely safe when using any options and accessories supplied by the manufacturer
of this product for use with it. Refer to Section 2 (Installation) of this manual for further details.
Pressure Safety
For this product to operate satisfactorily, pressurized gas must be connected to it. Observe all the
information contained within this manual and all local operation & installation requirements at the
intended location of use. Refer to Section 2 (Installation) of this manual for further details.
Hazardous Materials (WEEE, RoHS2 & REACH)
This product does not contain or release any prohibited chemicals listed on the SVHC (Substances
of Very High Concern) Candidate List. During the intended normal operation of this product it is not
possible for the user to come into contact with any hazardous materials. This product is designed to
be recyclable except where indicated, see relevant sections in this manual for further details.

QMA601 User’s Manual
Michell Instruments ix
Calibration (Factory Validation)
Prior to shipment, the analyzer undergoes stringent factory calibration to traceable standards. Due
to the inherent stability of the analyzer, regular factory calibration is not required under normal
operating conditions. The analyzer should perform reliably for many years with just basic maintenance,
housekeeping and regular field calibrations from the internal reference (moisture generator) or a
known external reference.
There are, however some consumables that will require periodic replacement.
• Moisture generator - typical lifetime of around 3 years.
• Desiccant column - typical lifetime of around 1 year, but this strongly
depends on the moisture content of the sample gas. The drier the sample
gas, the longer lifetime of the desiccant.
• Optional contamination trap - typical lifetime of around 1 year, a
column of activated charcoal that protects the Desiccant Column from
contamination in applications where the process gas composition contains
heavy hydrocarbon vapors.
Michell Instruments can provide a fully traceable factory calibration service for the analyzer and it is
recommended that this is considered at intervals of every year of the analyzer's life. Please contact
your local Michell Instruments' office or representative for further details (www.michell.com).
Repair and Maintenance
Apart from user-replaceable components required for routine operational maintenance described
above, the analyzer must only be maintained either by the manufacturer or an accredited service
agent. Refer to www.michell.com for details of Michell Instruments’ worldwide offices contact
information.

QMA601 User’s Manual
x97449 Issue 3, June 2018
Abbreviations
The following abbreviations are used in this manual:
AC alternating current
atm pressure unit (atmosphere)
barg pressure unit (=100 kP or 0.987 atm) gauge
°C degrees Celsius
°F degrees Fahrenheit
EU European Union
Hz Hertz
IEC International Electrotechnical Commission
kg kilogram
lb pound
lbs/MMscf pounds per million standard cubic foot
mA milliampere
mV millivolt(s)
mbar millibar
ml/min milliliters per minute
ppmWparts per million (by weight)
ppmVparts per million (by volume)
psig pound(s) per square inch (gauge)
RH relative humidity
RTU Remote Terminal Unit
V Volts
W Watts
" Inch

QMA601 User’s Manual
Michell Instruments 1
INTRODUCTION
1 INTRODUCTION
1.1 General
The QMA601 Moisture Analyzer is designed to provide reliable, fast and accurate
measurement of trace moisture content in a wide variety of process applications where
keeping moisture levels as low as possible is of critical importance.
The high-contrast capacitive button operated LCD display presents all measured data
to the user in a clear and understandable format. The main display incorporates a real-
time trend graph and alarm indicators based on the NAMUR 102 standard. A powerful
and intuitive HMI makes control, logging and configuration of analyzer parameters easy.
The analyzer provides two user-configurable analog outputs, and Modbus RTU/TCP
communications, allowing it to interface with a SCADA DCS system, or by a computer
using the dedicated application software. A set of 4 adjustable volt free alarm contacts
allow the QMA601 to be used for direct process control.
Use Your Preferred Communication Media
For greater flexibility, the QMA601 offers:
• Modbus RTU/TCP
• 2 user-configurable analog outputs
• Status and Process Alarms
Minimal & Straightforward Maintenance
Sophisticated analyzers are often complicated and require experience and special care
in use, increasing cost of ownership. The QMA601 differs through its very uncomplicated
approach to field service; the Desiccant Column is easy to replace via its mounting on
the sampling panel. The moisture generator has an average life span of 3 years after
which it can simply be replaced with a calibrated moisture generator supplied by Michell
Instruments.
Automated Calibration for Continued Reliability
The QMA601 incorporates an integrated automatic calibration system for complete
user confidence. Periodic calibration checks of sensor performance can be initiated
on demand, or automatically (at user defined intervals and time of day), providing a
verification of analyzer performance and automatically adjusting out any change. The
moisture generator at the core of this system is supplied with a calibration traceable to
NPL and NIST, but an external calibration reference source can also be used if desired.
During a calibration cycle, the Data Hold function will prevent any interruption of
dependant processes by holding the analog outputs at the same level for the duration
of the calibration.

QMA601 User’s Manual
297449 Issue 3, June 2018
INTRODUCTION
Full Hazardous Area Certification
The analyzer is ATEX, IECEx and cCSAus certified. The main unit (electronics and
sensing) and associated sampling system may be mounted at a convenient location
next to the pipeline or process, with gas sample and vent connections. The analyzer
is supplied in either a 85-264 V AC version or a 24 V DC version. The product serial
number label will identify the required operating power supply.
Purpose Designed Sample Systems
Sample extraction, handling and conditioning techniques are of critical importance to
assure optimal performance and reliability of all gas analyzers which accurately quantify
specific components within a process gas composition. Three sample systems have
been designed for the most common process moisture analyzer applications:
• Natural Gas Glycol Dehydration & Transmission with an advanced
membrane filter to combat liquid contamination.
• Trace Moisture in High Purity & Petrochemical Gases with protection
against particulates.
• Trace moisture for Asymmetric Cycle variant, includes membrane filter
and 3 way valve for purge gas.
Our QMA601 sample systems facilitate regulation of pressure and flow, and the removal
of contaminants, delivering a properly conditioned sample to the analyzer for reliable
measurements, and trouble-free operation. The integrated bypass system increases
transport speed of the sample while reducing gas wastage. Each high quality sample
system is constructed from 316 stainless steel components, with BS EN 10204 3.1
material certificates available on request.
1.2 Theory of Operation
A pair of frequency-matched quartz crystal oscillators are used for measurement and
are both exposed to the sample gas. The measurement crystal features a hygroscopic
coating to adsorb moisture, whereas the reference crystal is uncoated. As the hygroscopic
coating on the measurement crystal adsorbs moisture from the sample, the overall mass
of the crystal is increased, modifying the oscillation frequency in a precise, repeatable
and measurable manner.
The resulting measurement is highly accurate, and insensitive to changes in background
gas composition.

QMA601 User’s Manual
Michell Instruments 3
INTRODUCTION
1.3 Sample Gas Path
The QMA601 measurement system must be supplied with gas at the required pressure
(to match that of its calibration) via the 1/4'' female NPT gas inlet on the flame arrestor.
The flow is controlled automatically.
The sensor cell is located at the end of the sensor block and contains the sensor and
reference oscillators.
Figure 1 shows a schematic diagram of this sampling system.
SAMPLE
IN
SAMPLE
OUT
DD
HE1 HE2
V1 V2 V3
MFC
QCH
PS
MG
FC1 FC2 FC3
Key
DD Desiccant column MG Moisture generator
MFC Mass flow controller V1, V2, V3 Solenoid valves
QCH Sensor cell HE1, HE2 Heat exchanger
PS Pressure sensor FC1, FC2, FC3 Flow control
Figure 1
Measurement System

QMA601 User’s Manual
497449 Issue 3, June 2018
INSTALLATION
2 INSTALLATION
2.1 Analyzer Storage Instructions
In order for this product to be functional upon installation it should be stored in
accordance with the guidelines below:
• The product must be housed in a sheltered area, out of direct sunlight
and rain.
• The product should be stored to minimize the possibility of sitting in
ground water.
• The temperature within the storage environment should be maintained
between -20 to +60°C (-4 to +140°F).
• The humidity within the storage environment must be non-condensing.
• The storage environment must not expose the analyzer to any corrosive
elements.
• The product should stay assembled with its sample conditioning system
(if supplied).
• All electrical and process connections should remain disconnected and
capped.
• All protective coatings should remain in place until installation.
• For prolonged periods of storage, the lid of the packaging crate should be
removed to allow air to circulate.
• Any documentation supplied with the product should be removed from
the packaging crate and stored elsewhere to protect its integrity.
For the period from installation of the product to commissioning start-up, the following
precautions should be followed:
• The product and associated sampling system (if supplied) must remain
isolated from the process gas, and the enclosure should remain closed to
ensure ingress protection is maintained.
• If supplied, the sampling system enclosure heating/thermostat circuit
should be operated if the climatic temperature might fall below +5°C
(+41°F).
• At time of start-up the procedures contained in the user manuals for both
analyzer and sampling system must be followed.
If the product was previously in service/operation then the following precautions should
be followed before storage:
• Upon isolation from the gas sample the entire system should be purged
with a dry nitrogen gas before powering down of the analyzer.
• All connections and ports (gas and electrical) to the analyzer or sample
system (if provided) should be capped.
• If the product is not removed from its location, the electrical grounding of
the analyzer should remain in place.

QMA601 User’s Manual
Michell Instruments 5
INSTALLATION
2.2 Unpacking the Analyzer
Open the crate and carefully unpack the analyzer.
!
WARNING:
The analyzer weighs 35kg (77lbs) alone,
or 50kg (110lbs) in the crate
The accessories box should contain the following items:
• Traceable calibration certificate
• Application software CD
• Users manual
If there are any shortages please notify the supplier immediately.
NOTE: Retain the packaging in case the analyzer is returned for factory
calibration or service.
2.3 Lifting and Handling
!
WARNING:
Personnel must observe suitable lifting and handling
precautions.
The QMA601 is not designed as portable or transportable equipment. The product
should be rigidly fixed in position as per the full installation instructions.
The weight of the analyzer is 35kg (77lbs). Therefore, appropriate lifting and handling
techniques should be used during the installation process. Before commencing any lifting
or handling ensure that its intended location is suitable and appropriately prepared.
Make sure that mounting point design considerations have employed locally approved
safety factors.
When handling and installing this analyzer (particularly after removal from its packaging)
ensure that it is not dropped, impacted or subjected to high levels of vibration or
environmental conditions that may impair its operation.

QMA601 User’s Manual
697449 Issue 3, June 2018
INSTALLATION
2.4 Mounting the Analyzer
The analyzer is housed in an aluminum Exd enclosure suitable for wall or panel
mounting. Four mounting points are available with M10 clearance holes on fixing
centers of X = 308mm and Y = 312mm.
The enclosure provides environmental ingress protection IP66/NEMA4 and should be
mounted vertically in a location free of any appreciable vibration. It should be placed in
a shaded position to prevent heating effects through sun radiation. The weight of the
analyzer is 35kg (77lbs).
Conduit entries are intended for connection to threaded rigid metal conduit or other
wiring methods in accordance with Article 501 of the National Electrical Code ANSI/
NFPA 70-2005.
4 off M20
threaded entries External Earth Point Marking Label
Ø
410mm
(
16
.14”)
335mm (13.2”)
335mm
(13.2”) 308mm
(12.1”)
312mm (12.3”)
4 off M10
41mm
(1.6”) 50mm (2.0”)
97mm
(3.8”)
57mm (2.2”)
131mm (5.2”)
280mm (11.0”)
41mm
(1.6”)
66mm
(2.6”)
TOP VIEW
FRONT VIEW RIGHT VIEW
Sample In
Desiccant
Column Outlet
Enclosure
Breather
(do not obstruct)
Figure 2 Mounting Dimensions

QMA601 User’s Manual
Michell Instruments 7
INSTALLATION
2.5 Hazardous Area/Location Safety
This product is compliant for installation and use in a Hazardous Area/Location. All
certificates awarded to this product should be fully examined prior to installation and
use.
WARNING:
This product is certified safe for use in an ATEX Zone 1 and
Zone 2 / Class I, Division 1 area only. This product must not
be installed or used within a Zone 0 area.
WARNING:
This product must not be operated within an explosive
atmosphere greater than 1.1 bara (16 psia).
!
WARNING:
This product must not be operated with enriched oxygen
atmospheres (more than 21% oxygen content).
WARNING:
This product must not be operated outside of the
temperature range of +5 to +45°C (+41 to +113°F)
Refer to Appendix B for the Hazardous Area/Location certification details of this product.
Hazardous Area/Location certificates for this product may be downloaded from:
http://www.michell.com.
This product is fitted with a marking label that contains Hazardous Area/Location
information pertinent to the suitable location and installation.
During all installation and operation activities, local regulations and permitted working
routines must be observed. Installation should only be performed by competent
personnel and, where applicable, in accordance with IEC/EN 60079-14:2008 or local
equivalents.
Cable glands/barrier glands/conduit seals shall be installed in accordance with the
manufacturer’s instructions.
Repair and servicing of this equipment must only be carried out by the manufacturer. An
Installation and Maintenance Information Sheet is supplied separately to the manual.

QMA601 User’s Manual
897449 Issue 3, June 2018
INSTALLATION
2.6 Electrical Safety
DANGER
Electric
Shock Risk
WARNING:
During the installation of this product ensure that all
applicable national and local electrical safety regulations
are observed.
WARNING:
Isolate the power prior to installation.
WARNING:
Always ensure that power is switched off prior to accessing
the product for any purpose other than normal operation, or
prior to disconnecting any cables.
Fuse
This product is provided with an internally mounted fuse located beneath the power
connector.
The fuses are rated at 5 x 20mm anti-surge to IEC60127-2:
Mains 240 V AC 3 A
24 V DC 6.3 A
A replacement fuse can be obtained by contacting Michell Instruments' technical support.
2.6.1 Equipment Ratings and Installation Details
This equipment and all power isolation devices must be installed in a location and
position that allows safe and easy access to their operation and is able to rigidly support
the equipment.
For location and mounting arrangements - refer to the relevant sections of this manual
for further details.
Do not install this equipment in a location that would expose it to impact or high levels
of vibration. Installation of this equipment must include the provision of a suitable and
locally positioned power isolation switch or circuit breaker. Indication of the purpose
of the switch or circuit breaker is strongly recommended. An over-current protection
device should be rated to a maximum of 10 A. Ensure that the power supply is sufficient
to satisfy the instrument's power consumption requirements.
Any power supply terminals and voltages must be suitably separated from the other
input/output requirements of this product.

QMA601 User’s Manual
Michell Instruments 9
INSTALLATION
The product enclosure is supplied with an external protective earthing/grounding
terminal at the lower right hand side as shown in the figure below. As the first step
of the electrical installation - connect this earthing/grounding terminal to plant earth/
ground by a minimum 4mm2earth/ground bond strap. The earthing/grounding terminal
comprises of an earth bolt, 2 x plain washers and 1 x spring washer, which are all nickel
plated.
Figure 3 Earth Bolt And Nut Washer Assembly
Mains Powered Units
As a minimum, the power connection cable should be 3 core over sleeved,
with minimum 0.5mm insulation and rated at 300 V. Cables should have
Live (L), Neutral (N) and Earth [Ground] (E) conductors.
Ensure suitably rated power supply cables and glands are used to ensure that
electrical safety is maintained. Connect each of the Live (L), Neutral (N) and
Earth [Ground] (E) conductors to the similarly marked terminals (L, N, E) on
the Power In connector shown above.
24 V DC Units
The cable should be rated at a minimum of 10 A at 50 V DC with minimum
0.5mm insulation. Connect the +24 V conductor to the terminal marked +
and the 0 V conductor to the terminal marked -.
Before applying power, perform a continuity test to ensure that the power supply cable
and product are effectively connected to the protective earth. A protective earth terminal
is mounted internally and the Earth wire connected to it should never be disconnected.
Do not remove or exchange any of the cables, electrical components or any other parts
supplied with this product. Doing so will invalidate all warranties.
If installing rigid conduit, a stopping fitting must be installed within 46cm (18") of the
enclosure.
There are no additional or special electrical safety requirements other than those
referred to in this manual.

QMA601 User’s Manual
10 97449 Issue 3, June 2018
INSTALLATION
This product is designed to be safe under the following conditions: between a
temperature range of -40 to +60°C (-40 to +148°F), in maximum 80% relative humidity
for temperatures up to +31°C (+88°F) decreasing linearly to 50% RH at +50°C
(+122°F). Supply voltages of ±10% and transient over voltages up to Overvoltage
Category II. Pollution Degree 2. Altitudes up to 2000m. Outdoor mounting is permitted
using suitably rated glands equivalent to NEMA 4 / IP66. See Appendix A, Technical
Specification, for full operating parameters.
DANGER
Electric
Shock Risk
2.6.2 Power Connection
The product is provided with 4 x M20 threaded cable gland entries for customer
connection. Only these gland entry points may be used. The end user/installer is not
permitted to machine additional entries into the enclosure.
This equipment must be supplied with a voltage between the range of 85 to 264 V AC,
47/63 Hz (140 W max) or 24 V DC (140 W max) to function correctly. Cable entry into
the measurement system is made through the bottom of the enclosure.
For an 85/264 V AC powered unit the terminals are marked:
L Live (= IEC Brown)
N Neutral (= IEC Blue)
E Earth/Ground (= IEC Green/Yellow)
For a 24 V DC powered unit, the terminals are marked:
+ 24 V DC
- 0 V DC
All power connections are made via a removable screw terminal connector mounted on
the mains connection PCB shown in Figure 4.
Figure 4 24 V DC & 240 V AC Power Unit Connectors
All input and output connectors are 2-part pcb mounted type rated @ 300 V 10 A. The
detachable, screw terminal half of each connector is designed to accept 0.5 to 2.5mm2(24
-12 AWG)stranded or solid conductors. The connector 2-pin for 24 V DC and 3-pin for 240
V AC.