YOKOGAWA MLX User manual

IM 60A02S01-01E-A
8
th
Edition
User’s
Manual
IM 60A02S01-01E-A
Model MLX
Loop Powered Process Indicator

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IM 60A02S01-01E-A
Contents
Loop Powered Process Indicator........................................................................................ 1
Contents .......................................................................................................................................2
1. Introduction..............................................................................................................................3
1.1 Safe Use of This Product................................................................................................... 4
1.2 Warranty.............................................................................................................................. 5
1.3 ATEX Documentation......................................................................................................... 6
2. Handling Cautions...................................................................................................................8
2.1 Model and Specifications Check....................................................................................... 9
2.2 Unpacking........................................................................................................................... 9
2.3 Storage................................................................................................................................ 9
2.4 Selecting the Installation Location................................................................................... 9
2.5 Insulation Resistance and Dielectric Strength Test...................................................... 10
2.6 Installation of an Explosion-Protected Instrument........................................................ 11
2.6.1 Factory Mutual (FM) Certification............................................................................. 11
2.6.2 CENELEC ATEX Certification................................................................................... 16
2.6.3 Canadian Standards Association (CSA) Certification............................................ 22
2.6.4 IECEx Certification .................................................................................................... 25
2.7 EMC Conformity Standards............................................................................................. 29
2.8 Low Voltage Directive...................................................................................................... 29
3. Installation.............................................................................................................................30
3.1 Mounting Examples ......................................................................................................... 31
4. Wiring...................................................................................................................................... 32
4.1 Wiring Precautions........................................................................................................... 32
4.2 Selecting the Wiring Materials ........................................................................................ 32
4.3 Wiring................................................................................................................................ 33
4.3.1 Loop Configuration.................................................................................................... 33
5. Operation................................................................................................................................35
5.1 Overview ........................................................................................................................... 35
5.2 Setting Engineering Units................................................................................................ 41
6. Maintenance........................................................................................................................... 43
6.1 Overview ........................................................................................................................... 43
6.2 Calibration Instruments Selection.................................................................................. 43
6.3 Calibration......................................................................................................................... 43
6.4 Rotating Display Direction............................................................................................... 44
6.5 Cleaning............................................................................................................................ 44
7. General Specifications ..........................................................................................................45
7.1 Standard Specifications .................................................................................................. 45
7.2 Model and Suffix Codes................................................................................................... 46
7.5 Dimensions....................................................................................................................... 50
Revision Record.........................................................................................................................51

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1. Introduction
Thank you for purchasing the Model MLX Loop Powered Process Indicator. Your Model MLX
Process Indicator was precisely calibrated at the factory before shipment. To ensure both safety
and efficiency, please read this manual carefully before you operate the instrument.
The Model MLX field mounted indicator receives DC current signals from electronic transmitters
and indicates process measurement values. This instruction manual gives instructions on
handling, mounting, and wiring of the indicator.
■Regarding This Manual
•This manual should be provided to the end user.
•The contents of this manual are subject to change without prior notice.
•All rights reserved. No part of this manual may be reproduced in any form without
Yokogawa’s written permission.
•Yokogawa makes no warranty of any kind with regard to this manual, including, but not
limited to, implied warranty of merchantability and fitness for a particular purpose.
•If any question arises or errors are found, or if any information is missing from this
manual, please inform the nearest Yokogawa sales office.
•The specifications covered by this manual are limited to those for the standard type under
the specified model number break-down and do not cover custom-made instruments.
•Please note that changes in the specifications, construction, or component parts of the
instrument may not immediately be reflected in this manual at the time of change,
provided that postponement of revisions will not cause difficulty to the user from a
functional or performance standpoint.
•Yokogawa assumes no responsibilities for this product except as stated in the warranty.
•If the customer or any third party is harmed by the use of this product, Yokogawa
assumes no responsibility for any such harm owing to any defects in the product which
were not predictable, or for any indirect damages.
•The following safety symbols are used in this manual:

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W ARNING
Indicates a potentiallyhazardous situation which, if not avoided, could result in death or seriousinjury.
CAUTION
Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. It
may also be used to alert against unsafe practices.
IMPORTANT
Indicates that operating the hardware or software in this manner may damage it or lead to system failure.
NOTE
Draws attention to information essential for understanding the operation and features.
Directcurrent
1.1 Safe Use of This Product
For the safety of the operator and to protect the instrument and the system, please be sure to
follow this manual’s safety instructions when handling this instrument. If these instructions are
not heeded, the protection provided by this instrument may be impaired. In this case, Yokogawa
cannot guarantee that the instrument can be safely operated. Please pay special attention to the
following points:
(a) Installation
•This instrument may only be installed by an engineer or technician who has an expert
knowledge of this device. Operators are not allowed to carry out installation unless they
meet this condition.
•All installation shall comply with local installation requirements and the local electrical
code.
(b) Wiring
•The instrument must be installed by an engineer or technician who has an expert
knowledge of this instrument. Operators are not permitted to carry out wiring unless they
meet this condition.
•Before connecting the power cables, please confirm that there is no current flowing
through the cables and that the power supply to the instrument is switched off.
(c) Operation
•Do not open the covers when an explosive atmosphere is present.

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(d) Maintenance
•Please carry out only the maintenance procedures described in this manual. If you require
further assistance, please contact the nearest Yokogawa office.
•Care should be taken to prevent the build up of dust or other materials on the display
glass and the name plate.
(e) Modification
•Yokogawa will not be liable for malfunctions or damage resulting from any modification
made to this instrument by the customer.
1.2 Warranty
•The warranty shall cover the period noted on the quotation presented to the purchaser at
the time of purchase. Problems occurring during the warranty period shall basically be
repaired free of charge.
•If any problems are experienced with this instrument, the customer should contact the
Yokogawa representative from which this instrument was purchased or the nearest
Yokogawa office.
•If a problem arises with this instrument, please inform us of the nature of the problem and
the circumstances under which it developed, including the model specification and serial
number. Any diagrams, data and other information you can include in your
communication will also be helpful.
•The party responsible for the cost of fixing the problem shall be determined by Yokogawa
following an investigation conducted by Yokogawa.
•The purchaser shall bear the responsibility for repair costs, even during the warranty
period, if the malfunction is due to:
−Improper and/or inadequate maintenance by the purchaser.
−Malfunction or damage due to a failure to handle, use, or store the instrument in
accordance with the design specifications.
−Use of the product in question in a location not conforming to the standards specified
by Yokogawa, or due to improper maintenance of the installation location.
−Failure or damage due to modification or repair by any party except Yokogawa or an
approved representative of Yokogawa.
−Malfunction or damage from improper relocation of the product in question after
delivery.
−Reason of force majeure such as fires, earthquakes, storms/floods, thunder/lightening,
or other natural disasters, or disturbances, riots, warfare, or radioactive contamination.

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1.3 ATEX Documentation
This is only applicable to the countries in the European Union.
GB
All instruction manuals for ATEX Ex related products are available in English, German and French.
Should you require Ex related instructions in your local language, you are to contact your nearest
Yokogawa office or representative.
DK
Alle brugervejledninger for produkter relateret til ATEX Ex er tilgængelige på engelsk, tysk og fransk.
Skulle De ønske yderligere oplysninger om håndtering af Ex produkter på eget sprog, kan De rette
henvendelse herom til den nærmeste Yokogawa afdeling eller forhandler.
I
Tutti i manuali operativi di prodotti ATEX contrassegnati con Ex sono disponibili in inglese, tedesco e
francese. Se si desidera ricevere i manuali operativi di prodotti Ex in lingua locale, mettersi in contatto con
l’ufficio Yokogawa più vicino o con un rappresentante.
E
Todos los manuales de instrucciones para los productos antiexplosivos de ATEX están disponibles en
inglés, alemán y francés. Si desea solicitar las instrucciones de estos artículos antiexplosivos en su idioma
local, deberá ponerse en contacto con la oficina o el
representante de Yokogawa más cercano.
NL
Alle handleidingen voor producten die te maken hebben met ATEX explosiebeveiliging (Ex) zijn
verkrijgbaar in het Engels, Duits en Frans. Neem, indien u aanwijzingen op het gebied van
explosiebeveiliging nodig hebt in uw eigen taal, contact op met de dichtstbijzijnde vestiging van
Yokogawa of met een vertegenwoordiger.
SF
Kaikkien ATEX Ex -tyyppisten tuotteiden käyttöhjeet ovat saatavilla englannin-, saksan- ja
ranskankielisinä. Mikäli tarvitsette Ex -tyyppisten tuotteiden ohjeita omalla paikallisella kielellännne,
ottakaa yhteyttä lähimpään Yokogawa-toimistoon tai -edustajaan.
P
Todos os manuais de instruções referentes aos produtos Ex da ATEX estão disponíveis em Inglês, Alemão
e Francês. Se necessitar de instruções na sua lingual relacionadas com produtos Ex, deverá entrar em
contacto com a delegação mais próxima ou com um representante da Yokogawa.
F
Tous les manuels d’instruction des produits ATEX Ex sont disponibles en langue anglaise, allemande et
française. Si vous nécessitez des instructions relatives aux produits Ex dans votre langue, veuillez bien
contacter votre représentant Yokogawa le plus proche.
D

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Alle Betriebsanleitungen für ATEX Ex bezogene Produkte stehen in den Sprachen Englisch, Deutsch und
Französisch zur Verfügung. Sollten Sie die Betriebsanleitungen für Ex-Produkte in Ihrer Landessprache
benötigen, setzen Sie sich bitte mit Ihrem örtlichen Yokogawa-Vertreter in Verbindung.
S
Alla instruktionsböcker för ATEX Ex (explosionssäkra) produkter är tillgängliga på engelska, tyska och
franska. Om Ni behöver instruktioner för dessa explosionssäkra produkter på annat språk, skall Ni
kontakta närmaste Yokogawakontor eller representant.

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2. Handling Cautions
This chapter provides important information on how to handle the MLX Loop Powered Process
Indicator. Read this carefully before using the indicator.
The MLX indicator is thoroughly tested at the factory before shipment. When taking delivery of
an instrument, visually check it to make sure that no damage occurred during shipment.
Also check that the indicator mounting hardware shown in figure 2.1 is included. After checking
the indicator, carefully repack it in its box and keep it there until you are ready to install it.
Figure 2.1 MLX Mounting Hardware

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2.1 Model and Specifications Check
The model name and specifications are written on the name plate attached to the case.
MODEL: Specified model code.
SUFFIX: Specified suffix code.
MFG: Year of manufacture.
NO.: Serial number.
INPUT: Input signal (4-20mA DC).
CALIB RANGE: Specified calibration range.
Figure 2.2 MLX Name Plate
2.2 Unpacking
Keep the indicator in its original packaging to prevent it from being damaged during shipment.
Do not unpack the indicator until it reaches the installation site.
2.3 Storage
The following precautions must be observed when storing the instrument, especially for a long
period.
(a) Select a storage area which meets the following conditions:
•It is not exposed to rain or subject to water seepage/leaks.
•Vibration and shock are kept to a minimum.
•It has an ambient temperature and relative humidity within the following ranges.
Ambient temperature: –40 to 80°C (approval codes may affect limits)
Relative humidity: 0% to 100% R.H.
Preferred temperature and humidity: approx. 25°C and 65% R.H.
(b) When storing the indicator, repack it carefully in the packaging that it was originally
shipped with.
2.4 Selecting the Installation Location
(1) The MLX is designed to withstand severe environmental conditions. However, to ensure
that it will provide years of stable and accurate performance, take the following
precautions when selecting the installation location.
(2) Ambient Temperature
(3) Avoid locations subject to wide temperature variations or a significant temperature
gradient. If the location is exposed to radiant heat from plant equipment, provide
adequate thermal insulation and/or ventilation.

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(4) Ambient Atmosphere
(5) Do not install the indicator in a corrosive atmosphere. If this cannot be avoided, there
must be adequate ventilation as well as measures to prevent the leaking of rain water and
the presence of standing water in the conduits.
(6) Shock and Vibration
(7) Although the MLX is designed to be relatively resistant to shock and vibration, an
installation site should be selected where this is kept to a minimum.
2.5 Insulation Resistance and Dielectric Strength Test
Since the MLX has undergone insulation resistance and dielectric strength tests at the factory
before shipment, normally these tests are not required. If the need arises to conduct these tests,
heed the following:
(1) Do not perform such tests more frequently than is absolutely necessary. Even test
voltages that do not cause visible damage to the insulation may degrade the insulation
and reduce safety margins.
(2) Never apply a voltage exceeding 500 V DC (100 V DC with an internal lightning protector)
for the insulation resistance test, nor a voltage exceeding 500 V AC (100 V AC with an
internal lightning protector) for the dielectric strength test.
(3) Before conducting these tests, disconnect all signal lines from the transmitter terminals.
The procedure for conducting these tests is as follows:
•Insulation Resistance Test
(1) Short-circuit the + and – SUPPLY terminals in the terminal box.
(2) Turn OFF the insulation tester. Then connect the insulation tester plus (+) lead
wire to the shorted SUPPLY terminals and the minus (–) lead wire to the grounding
terminal.
(3) Turn ON the insulation tester power and measure the insulation resistance. The
voltage should be applied as briefly as possible to verify that the insulation
resistance is at least 20 MΩ.
(4) After completing the test and being very careful not to touch exposed conductors
disconnect the insulation tester and connect a 100 kΩ resistor between the
grounding terminal and the short-circuiting SUPPLY terminals. Leave this resistor
connected at least one second to discharge any static potential. Do not touch the
terminals while it is discharging.
•Dielectric Strength Test
(1) Short-circuit the + and – SUPPLY terminals in the terminal box.
(2) Turn OFF the dielectric strength tester. Then connect the tester between the
shorted SUPPLY terminals and the grounding terminal. Be sure to connect the
grounding lead of the dielectric strength tester to the ground terminal.
(3) Set the current limit on the dielectric strength tester to 10mA, then turn ON the
power and gradually increase the test voltage from ‘0’ to the specified voltage.
(4) When the specified voltage is reached, hold it for one minute.
(5) After completing this test, slowly decrease the voltage to avoid any voltage surges.

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2.6 Installation of an Explosion-Protected Instrument
WARNING
If a customer makes a repair or modification and the instrument is not restored to its
original condition, its safety may be compromised and the instrument may be hazardous
to operate. Please contact Yokogawa before making any repair or modification to an
instrument.
CAUTION
This instrument has been tested and certified as being Explosionproof. Please note that
severe restrictions apply to this instrument’s construction, installation, external wiring,
maintenance and repair. A failure to abide by these restrictions could make the instrument
a hazard to operate.
WARNING
Maintaining the safety of Explosionproof equipment requires great care during mounting,
wiring, and piping. Safety requirements also place restrictions on maintenance and repair.
Please read the following sections very carefully.
2.6.1 Factory Mutual (FM) Certification
1) Technical Data
a. FM Explosionproof/Dust-Ignition-Proof Type
Caution for FM Explosionproof/Dust-Ignition-Proof type.
Note 1. Model MLX Loop Process Indicators with optional code /FF1 applicable for
use in potentially hazardous locations:
•Certificate No. 4000798
•Conforms to: FM 3600, FM 3615, FM 3616, UL 1203
•Explosionproof/Dust-Ignition-Proof for Class I, II, II; Division 1 & 2, Groups A –
G; Class I, Zone 1, Group IIC T4
•Enclosure rating: NEMA 4X.
•Temperature Class: T4
•Ambient Temperature: –40°C to 80°C
Note 2. Wiring
•For an ambient temperature ≥70°C, heat resistant cables shall be used with a
rating of at least 20°C above the ambient temperature.

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•In hazardous location, wiring shall be in conduit.
WARNING: A SEAL SHALL BE INSTALLED WITHIN 50 cm OF THE
ENCLOSURE.
•When installed in Division 2,“FACTORY SEALED, CONDUIT SEAL NOT
REQUIRED”.
•All wiring shall comply with National Electrical Code ANSI/NEPA70 and Local
Electrical Codes.
Note 3. Installation
•Installation should be in accordance with ANSI/ISA RP12.6 “Installation of
Intrinsically Safe Systems for Hazardous (Classified) Locations” and the
National Electric Code (ANSI/NFPA 70).
•Strictly observe the “WARNING” on the attached nameplate.
WARNING: OPEN CIRCUIT BEFORE REMOVING COVER. INSTALL IN
ACCORDANCE WITH THE INSTRUCTION MANUAL.
Note 4. Maintenance and Repair
•The instrument modification or parts replacement by other than authorized
representative of Yokogawa Corporation of America is prohibited and will void
Factory Mutual Explosionproof Approval.
•
Note 5. Special Conditions for Safe Use
•In the case where the enclosure of the MLX is made of aluminum, if it is
mounted in an area requiring Class 1 Division 1 equipment, it must be installed
such, that, in the event of rare incidents or rare malfunction, ignition sources
due to impact and friction sparks are excluded.
W ARNING
ELECTROSTATIC CHARGE HAZARD MAY CAUSE AN EXPLOSION
HAZARDS DUE TO THE PAINT THICKNESS OF THE EQUIPMENT NOT
MEETING THE REQUIREMENTS FOR AVOIDING ELECTROSTATIC
DISCHARGE ON GROUP II AND GROUP III ELECTRICAL EQUIPMENT.
AVOID ANY ACTIONS THAT CAUSE AN ELECTROSTATIC DISCHARGE
OF THE ENCLOSURE, SUCH AS RUBBING WITH A DRY CLOTH ON ANY
SURFACE OF THE PRODUCT. PRECAUTIONS SHALL BE TAKEN TO
MINIMIZE THE RISK FROM ELECTROSTATIC DISCHARGE OF PAINTED
OR COATED PARTS OF EQUIPMENT.
b. FM Intrinsically Safe/FM Explosionproof/Dust-Ignition-Proof Type
Caution for FM Intrinsically Safe/FM Explosionproof/Dust-Ignition-Proof type.
Note 1. Model MLX Loop Process Indicators with optional code /FU1 applicable for use in
potentially hazardous locations:

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•Certificate No. 4000798
•Conforms to: FM 3600, FM 3610, FMRC 3611, FM 3615, FM 3616, UL 913, UL
1203, UL 60079-0, UL 60079-11
• Explosionproof/Dust-Ignition-Proof for:
- Class I, II, III; Groups A -G; Divisions 1 & 2.
- Class I, Zone 1, Group IIC T4.
- Tamb. –40°C to 80°C
• Intrinsically Safe for:
- Class I, Division 1, II, III; Groups A -G; Divisions 1 & 2.
- Zone 20, Class I, Zone 0
- AEx ia IIC T4
- Tamb. –40°C to 80°C
• Non-Incendive for:
- Class I, II, III; Groups A - D, F, G; Divisions 2.
- Class I, Zone 2, Group IIC T4.
- Tamb. –40°C to 80°C
• Enclosure rating: NEMA 4X.
• Temperature Class: T4
• Ambient Temperature: –40°C to 80°C
Note 2. Entity Parameters
• Intrinsically Safe Apparatus Parameters
[Groups A - G]
Ui = 28 V Ci = 0 pF
Ii = 115 mA Li = 0 µH
Pi = 0.65 W
•Non-Incendive Apparatus Parameters
[Groups A – D, F, G]
Ui = 30 V
Ii = 150 mA
Pi = 0.85 W
Note 3. Wiring
• All wiring shall comply with National Electrical Code ANSI/NEPA70 and Local
Electrical Codes.
• For an ambient temperature ≥70°C, heat resistant cables shall be used with a
rating of at least 20°C above the ambient temperature.
• In hazardous location, wiring shall be in conduit.
WARNING: A SEAL SHALL BE INSTALLED WITHIN 50 cm OF THE
ENCLOSURE.
When installed in Division 2,“FACTORY SEALED, CONDUIT SEAL NOT
REQUIRED”.
Note 4. Installation
•Installation should be in accordance with ANSI/ISA RP12.6 “Installation of
Intrinsically Safe Systems for Hazardous (Classified) Locations” and the
National Electric Code (ANSI/NFPA 70).

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•The safety barrier must be FM approved.
• Strictly observe the “WARNING” on the attached nameplate.
WARNING: SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC
SAFETY.
WARNING: DO NOT OPEN COVERS WHEN AN EXPLOSIVE ATMOSHPERE
MAY BE PRESENT. INSTALL IN ACCORDANCE WITH THE INSTRUCTION
MANUAL.
Note 5. Maintenance and Repair
• The instrument modification or parts replacement by other than authorized
representative of Yokogawa Electric Corporation is prohibited and will void Factory
Mutual Explosionproof Approval.
Note 6. Special Conditions for Safe Use
• In the case where the enclosure of the MLX is made of aluminum, it must be
installed such, that, even in the event of rare incidents, ignition sources due to impact
and friction sparks are excluded.
W ARNING
ELECTROSTATIC CHARGE HAZARD MAY CAUSE AN EXPLOSION
HAZARDS DUE TO THE PAINT THICKNESS OF THE EQUIPMENT NOT
MEETING THE REQUIREMENTS FOR AVOIDING ELECTROSTATIC
DISCHARGE ON GROUP II AND GROUP III ELECTRICAL EQUIPMENT.
AVOID ANY ACTIONS THAT CAUSE AN ELECTROSTATIC DISCHARGE
OF THE ENCLOSURE, SUCH AS RUBBING WITH A DRY CLOTH ON ANY
SURFACE OF THE PRODUCT. PRECAUTIONS SHALL BE TAKEN TO
MINIMIZE THE RISK FROM ELECTROSTATIC DISCHARGE OF PAINTED
OR COATED PARTS OF EQUIPMENT.

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MLX Loop
Indicator
-+
+
2- Wire
Transmitter
-
+
FM Certified
Equipment
(non-incendive)
Non-Hazardous Area
Hazardous Area
4-20mA
Group IIC, Zone 2 T4
Class I, II, III, Division 2
Groups A - D, F, G
[Non-incendive]
MLX Loop
Indicator
-+
+
2- Wire
Transmitter
-
++
Safety Barrier
--
Non-Hazardous Area
Hazardous Area
4-20mA
+
General
Purpose
Equipment
-
Group IIC, Zone 0
Class I, II, III, Division1 & 2
Groups A - G
[Intrinsically safe]

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2.6.2 CENELEC ATEX Certification
1) Technical Data
a. CENELEC ATEX Intrinsically Safe/CENELEC ATEX Flameproof/
CENELEC ATEX Non-Incendive Type
Caution for CENELEC ATEX Intrinsically Safe/CENELEC ATEX Flameproof/ CENELEC
ATEX Non-Incendive Type.
Note 1. Model MLX Loop Process Indicators with optional code /KU21 applicable for use
in potentially hazardous locations:
•Certificate No. ITS13ATEX27856X
•Certificate No. ITS13ATEX17857X
•Certificate No. ITS13ATEX47858X
• Applicable Standard: EN 60079-0:2009, EN 60079-11:2007, EN 60079-26:2007
• Type of Protection and Marking code:
II 1G Ex ia IIC T4 Ga
II 2G Ex d IIC T4 Gb
II 2D Ex tb IIC T135 Db
II 3G Ex nA IIC T4 Gc
• Tamb. –40°C to 80°C
• Enclosure rating: IP66 and IP67
Note 2. Electrical Data
• In the case where the type of explosion protection is intrinsically safe, Ex ia IIC
T4 Ga, only connect to a certified intrinsically safe circuit with the following maximum
values:
Ui = 28 V
Ii = 115 mA
Pi = 0.65 W
Effective internal capacitance; Ci = 0
Effective internal inductance; Li = 0
• In the case where the type of explosion protection is Non-Incendive, Ex nA IIC
T4 Gc, only connect to a certified intrinsically safe circuit with the following maximum
values:
Ui = 30 V
Ii = 150 mA
Pi = 0.85 W
Note 3. Wiring
• For an ambient temperature ≥70°C, heat resistant cables shall be used with a
rating of at least 20°C above the ambient temperature.

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• All wiring shall comply with local installation requirements. (Refer to the
installation diagram)
Note 4. Installation
• Observe WARNING on nameplate. (Refer to the installation diagram)
WARNING: AFTER DE-ENERGIZING, DELAY 5 MIN BEFORE OPENING
COVER.
• When used in a potentially explosive atmosphere, requiring the use of apparatus
of equipment category 1D or 2D, certified cable entry devices shall be used that
are suitable for the application and correctly installed.
Note 5. Maintenance and Repair
• The instrument modification or parts replacement by other than authorized
representative of Yokogawa Electric Corporation is prohibited and will void Intrinsically
Safe Certification.
Note 6. Special Conditions for Safe Use
• In the case where the enclosure of the MLX is made of aluminum, if it is mounted
in an area requiring Category 1 G equipment (EPL Ga), it must be installed such, that,
in the event of rare incidents or rare malfunction, ignition sources due to impact and
friction sparks are excluded.
W ARNING
To satisfy IP66 or IP67, apply waterproof glands to the electrical connection
port.
W ARNING
ELECTROSTATIC CHARGE HAZARD MAY CAUSE AN EXPLOSION
HAZARDS DUE TO THE PAINT THICKNESS OF THE EQUIPMENT NOT
MEETING THE REQUIREMENTS FOR AVOIDING ELECTROSTATIC
DISCHARGE ON GROUP II AND GROUP III ELECTRICAL EQUIPMENT.
AVOID ANY ACTIONS THAT CAUSE AN ELECTROSTATIC DISCHARGE
OF THE ENCLOSURE, SUCH AS RUBBING WITH A DRY CLOTH ON ANY
SURFACE OF THE PRODUCT. PRECAUTIONS SHALL BE TAKEN TO
MINIMIZE THE RISK FROM ELECTROSTATIC DISCHARGE OF PAINTED
OR COATED PARTS OF EQUIPMENT.

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MLX Loop
Indicator
-+
+
2- Wire
T
ransmitter
-
+
[Ex ic] Certified
Equipment
(non-incendive)
Non-Hazardous Area
Hazardous Area
4-20mA
Group IIC, Zone 2
[Non-incendive]
MLX Loop
Indicator
-+
+
2- Wire
Transmitter
-
++
Safety Barrier
--
Non-Hazardous Area
Hazardous Area
4-20mA
+
General
Purpose
Equipment
-
Group IIC, Zone 0
[Intrinsically safe]

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Note 4. Maintenance and Repair
•The instrument modification or parts replacement by other than authorized
representative of Yokogawa Corporation of America is prohibited and will void
Intrinsically Safe Certification.
Note 5. Special Conditions for Safe Use
•In the case where the enclosure of the MLX is made of aluminum, if it is mounted
in an area requiring Category 1 G equipment (EPL Ga), it must be installed such,
that, in the event of rare incidents or rare malfunction, ignition sources due to
impact and friction sparks are excluded.
2) Nameplate
•Nameplate for FM Explosionproof/Dust Ignition-proof type (Option /FF1)
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
MLX
4000798
Explosionproof/Dust-Ignition-Proof for Class I, II, III; Groups A - G;
Divisions 1 & 2
Class I, Zone 1, Group IIC T4
Temp. Class: T4
Tamb.: -40°C to 80°C
Enclosure: NEMA 4X
WARNING
Conforms to: FM 3600,
FM 3615, UL 1203.
WARNING: DO NOT OPEN COVERS WHEN AN EXPLOSIVE
ATMOSPHERE MAY BE PRESENT. INSTALL IN
ACCORDANCE WITH THE INSTRUCTION MANUAL.
4-20mA DC
M1275BS
•Nameplate for FM Intrinsically Safe/Explosionproof/Dust-Ignition-proof/Non-Incendive
type (Option /FU1)
Intrinsically Safe for Class I II, III; Groups A - G; Divisions 1 & 2;
Zone 20, Class I, Zone 0, AEx ia IIC T4 Ga -40°C < Ta < +80°C
Ui = 28V, Ii = 115mA, Pi = 0.65W, Ci = 0uF, Li = 0mH
Explosionproof/Dust-Ignition-Proof for Class I, II, III; Groups A - G;
Divisions 1 & 2
Class I, Zone 1, Group IIC, T4 Tamb. -40°C to 80°C
Non-Incendive for Class I, II, III; Groups A - D, F, G; Division 2
Class I, Zone 2, Group IIC
T4 Tamb. -40°C to 80°C
Enclosure: NEMA 4X
WARNING
WARNING: SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY.
WARNING: DO NOT OPEN COVERS WHEN AN EXPLOSIVE ATMOSPHERE
MAY BE PRESENT. INSTALL IN ACCORDANCE WITH THE INSTRUCTION
MANUAL.
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
Conforms to: FM 3600,
FM 3610, FMRC 3611,
FM 3615, FM 3616, UL 913,
UL 1203, UL 60079-0,
UL 60079-11.
4000798
4-20mA DC
M1275DT
•Nameplate for ATEX Intrinsically Safe/Flameproof/Dustproof/Non-Incendive type (Option
/KU21)
Cert. No: ITS13ATEX27856X
Cert. No: ITS13ATEX17857
Cert. No: ITS13ATEX47858II 1G Ex ia IIC T4 Ga
Ui = 28V, Ii = 115mA, Pi = 0.65W, Ci = 0uF, Li = 0mH
II 2G Ex d IIC T4 Gb
II 2D Ex tb IIC T135 Db
II 3G Ex nA IIC T4 Gc
Tamb. -40°C to +80°C
Enclosure: IP66 and IP67
WARNING
AFTER DE-ENERGIZING, DELAY 5 MIN BEFORE
OPENING COVER. WHEN THE AMBIENT TEMP. =
70°C, USE HEATRESISTING CABLE RATED = 90°C.
INSTALL IN ACCORDANCE WITH THE INSTRUCTION MANUAL.
0359
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
4-20mA DC
M1275DU
•Nameplate for CSA Intrinsically Safe/Explosionproof/Dust-Ignition-proof/Non-Incendive
type (Option /CU1)

Page 20 of 51
IM 60A02S01-01E-A
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
4-20mA DC
Intrinsically Safe (Securite Intrinseque) for Class I II, III; Groups A - G;
Divisions 1 & 2; Zone 20, Class I, Zone 0, AEx ia IIC T4 Ga -40°C < Ta < +80°C
Ui = 28V, Ii = 115mA, Pi = 0.65W, Ci = 0uF, Li = 0mH
Explosionproof/Dust-Ignition-Proof for Class I, II, III; Groups A - G;
Divisions 1 & 2
Class I, Zone 1, Group IIC, T4 Tamb. -40°C to 80°C
Nonincendive for Class I, II, III; Groups A - D, F, G; Division 2
Class I, Zone 2, Group IIC T4 Tamb. -40°C to 80°C
Enclosure: "Type 4X"
WARNING
WARNING: SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY
ADVERTISSEMENT: LA SUBSTITUTION DE COMPOSANTS PEUT
COMPROMETTRE LA SECURITE INTRINSEQUE .
WARNING: DO NOT OPEN COVERS WHEN AN EXPLOSIVE ATMOSPHERE
MAY BE PRESENT. INSTALL IN ACCORDANCE WITH THE INSTRUCTION
MANUAL. ATTENTION: NE PAS OUVRIR Si des explosifs ATMOSPHERE
peuvent être présents. INSTALLER EN SELON LE MODE D'EMPLOI.
4000798
Certified to: CSA-C22.2 No. 25,
CSA-C22.2 No. 30, CSA-C22.2
No. 157, CSA-C22.2 No. 213,
CSA-C22.2 No. 60079-0,
CAN/CSA E60079-11.
M1275DV
•Nameplate for IEC Intrinsically Safe/Flameproof/Dustproof/Non-Incendive type (Option
/SU2)
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
Cert. No: IECEx ETL 13.0028X
Cert. No: IECEx ETL 13.0029
Cert. No: IECEx ETL 13.0030
Ex ia IIC T4 Ga
Ui = 28V, Ii = 115mA, Pi = 0.65W, Ci = 0uF, Li = 0mH
Ex d IIC T4 Gb
Ex tb IIC T135 Db
Ex nA IIC T4 Gc
Tamb. -40°C to +80°C
Enclosure: IP66 and IP67
WARNING
AFTER DE-ENERGIZING, DELAY 5 MIN BEFORE
OPENING COVER. WHEN THE AMBIENT TEMP.
=
70°C, USE HEATRESISTING CABLE RATED = 90°C.
INSTALL IN ACCORDANCE WITH THE INSTRUCTION MANUAL.
4-20mA DC
M1275DW
•Nameplate for Combined Approval type (Option /V1U – Combination of Options FU1,
KU21, and CU1)
ASSEMBLED IN USA WITH
FOREIGN AND DOMESTIC
PARTS
0359
Intrinsically Safe (Securite Intrinseque)for Class I II, III; Groups A - G; Divisions 1 & 2
Zone 20 Class I, Zone 0, AEx ia IIC T4 Ga; II 1G Ex ia IIC T4 Ga -40°C < Ta < +80°C
Ui = 28V, Ii = 115mA, Pi = 0.65W, Ci = 0uF, Li = 0mH
Cert. No. ITS13ATEX27856X, IECEx ETL 13.0028X
Explosionproof/Dust-Ignition-Proof for Class I, II, III; Groups A - G; Divisions 1 & 2
Class I, Zone 1, Group IIC; II 2G Ex d IIC T4 Gb; II 2D Ex tb IIIC T135 Db
Tamb. -40°C to 80°C Cert. No. ITS13ATEX17857, IECEx ETL 130029
Nonincendive for Class I, II, III; Groups A - D, F, G; Division 2
Class I, Zone 2, Group IIC; II 3G Ex nA IIC T4 Gc Tamb. -40°C to 80°C
Cert. No. ITS13ATEX47858, IECEx ETL 13.0030
Enclosure: NEMA 4X, IP66, IP67
WARNING
WARNING: SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY
ADVERTISSEMENT: LA SUBSTITUTION DE COMPOSANTS PEUT
COMPROMETTRE LA SECURITE INTRINSEQUE .
WARNING: DO NOT OPEN COVERS WHEN AN EXPLOSIVE ATMOSPHERE
MAY BE PRESENT. INSTALL IN ACCORDANCE WITH THE INSTRUCTION
MANUAL. ATTENTION: NE PAS OUVRIR Si des explosifs ATMOSPHERE
peuvent être présents. INSTALLER EN SELON LE MODE D'EMPLOI.
Conforms to: FM 3600, FM
3610, FM 3611, FM 3615 FM
3616, UL 913, UL 1203, UL
60079-0,11.
Certified to: CSA-C22.2 No. 25,
30, 157, 213, 60079-0, 60079-11.
4-20mA DC
4000798
M1275DX