Siemens 3RS2 User manual

Industrial Controls
Monitoring and control devices
3RS2 temperature monitoring
relay
Equipment Manual
02/2022
A5E42462552002A/RS-AB/002
Introduction 1
Safety instructions,
standards 2
ATEX 3
Analog devices 4
Digital devices 5
Digital devices with IO-Link 6
Sensor expansion module 7
Thermocouples 8
Resistance sensors 9
Circuit diagrams 10
Connection 11
Mounting 12
Technical data 13
CAx data 14
Spare parts/accessories 15
Process data and data sets 16

Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent damage
to property. The notices referring to your personal safety are highlighted in the manual by a safety alert symbol, notices
referring only to property damage have no safety alert symbol. These notices shown below are graded according to
the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will be
used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to property
damage.
Quali󹪝ed Personnel
The product/system described in this documentation may be operated only by personnel quali󹪝ed for the speci󹪝c
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Quali󹪝ed personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended or
approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and maintenance
are required to ensure that the products operate safely and without any problems. The permissible ambient
conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identi󹪝ed by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication may
be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software described.
Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the information in this
publication is reviewed regularly and any necessary corrections are included in subsequent editions.
Siemens AG
Smart Infrastructure
Electrical Products
Postfach 10 09 53
93009 Regensburg
GERMANY
A5E42462552002A/RS-AB/002
Ⓟ 01/2022 Subject to change
Copyright © Siemens AG 2020.
All rights reserved

Table of contents
1 Introduction ........................................................................................................................................... 7
1.1 Required basic knowledge.................................................................................................... 7
1.2 Scope of the manual ............................................................................................................ 7
1.3 Operating Instructions ......................................................................................................... 7
1.4 Siemens Industry Online Support ......................................................................................... 7
1.5 Siemens Industry Online Support app................................................................................... 9
1.6 Support Request .................................................................................................................. 9
1.7 Security information ............................................................................................................ 9
1.8 Recycling and disposal ....................................................................................................... 10
2 Safety instructions, standards ............................................................................................................. 11
2.1 Product-speci󹪝c safety instructions..................................................................................... 11
2.1.1 Hazardous Voltage ............................................................................................................. 11
2.1.2 Intended use...................................................................................................................... 11
2.1.3 Radio interference.............................................................................................................. 12
2.2 Standards, approvals and certi󹪝cates .................................................................................. 12
3 ATEX..................................................................................................................................................... 15
3.1 Safety and commissioning instructions for hazardous areas ................................................ 15
3.2 Use in areas subject to an explosion hazard due to gases or dust......................................... 16
4 Analog devices..................................................................................................................................... 17
4.1 Applications....................................................................................................................... 17
4.2 General functions .............................................................................................................. 17
4.3 Performance characteristics ............................................................................................... 18
4.4 Connection systems........................................................................................................... 18
4.5 Sensor types ...................................................................................................................... 19
4.6 Measuring ranges .............................................................................................................. 19
4.7 Temperature monitoring .................................................................................................... 20
4.8 Operator control ................................................................................................................ 21
4.8.1 Operator controls and display elements, settings, measuring ranges................................... 21
4.9 Time diagrams................................................................................................................... 22
5 Digital devices ..................................................................................................................................... 25
5.1 Applications....................................................................................................................... 25
5.2 General functions .............................................................................................................. 26
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5.3 Standard function .............................................................................................................. 26
5.4 Special functions ............................................................................................................... 27
5.4.1 Safety function .................................................................................................................. 27
5.4.2 Temperature limiter TB ...................................................................................................... 28
5.4.3 Temperature monitor TW ................................................................................................... 30
5.4.4 Communication ................................................................................................................. 31
5.5 Performance characteristics ............................................................................................... 31
5.6 Connection systems........................................................................................................... 32
5.7 Sensor types ...................................................................................................................... 32
5.8 Measuring ranges .............................................................................................................. 33
5.9 Using sensors .................................................................................................................... 34
5.10 Operator control ................................................................................................................ 34
5.10.1 Operator controls and display elements.............................................................................. 34
5.10.2 Display............................................................................................................................... 36
5.10.3 Menu-based operation....................................................................................................... 37
5.10.4 Reset ................................................................................................................................. 43
5.11 Time diagrams................................................................................................................... 44
5.12 Diagnostics........................................................................................................................ 47
6 Digital devices with IO-Link ................................................................................................................. 49
6.1 Performance characteristics ............................................................................................... 49
6.2 Communication ................................................................................................................. 50
6.3 Connection options for IO‑Link........................................................................................... 50
6.4 Time diagrams................................................................................................................... 52
6.5 Con󹪝guring with STEP 7 ..................................................................................................... 55
6.5.1 Con󹪝guring with STEP 7 - prerequisites............................................................................... 55
6.5.2 Con󹪝guring with STEP 7 and S7-PCT ................................................................................... 56
6.5.3 Con󹪝guring with STEP 7 and S7-PCT /GSD variant) .............................................................. 56
6.6 Con󹪝guring without STEP 7................................................................................................ 57
6.6.1 Con󹪝guring without STEP 7 - prerequisites.......................................................................... 57
6.6.2 Con󹪝guring without STEP 7................................................................................................ 57
6.7 Module replacement.......................................................................................................... 58
6.7.1 Module replacement (replacement of an IO‑Link device)..................................................... 58
6.7.2 Module replacement with PG/PC ........................................................................................ 58
6.7.3 Module replacement without PG/PC ................................................................................... 58
6.8 Integration into the SIMATIC environment .......................................................................... 59
6.9 Acyclic data exchange with the FB IOL_CALL....................................................................... 59
6.10 Diagnostics via IO‑Link ....................................................................................................... 60
7 Sensor expansion module ................................................................................................................... 63
7.1 Versions............................................................................................................................. 63
7.2 Communication ................................................................................................................. 63
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7.3 Connection systems........................................................................................................... 63
7.4 Sensor types ...................................................................................................................... 63
7.5 Operator control ................................................................................................................ 64
7.5.1 LEDs .................................................................................................................................. 64
7.5.2 Status display..................................................................................................................... 65
8 Thermocouples .................................................................................................................................... 67
8.1 De󹪝nition........................................................................................................................... 67
8.2 Characteristic curves of thermocouples .............................................................................. 67
9 Resistance sensors............................................................................................................................... 69
9.1 De󹪝nition........................................................................................................................... 69
9.2 Characteristic curves .......................................................................................................... 69
10 Circuit diagrams................................................................................................................................... 71
10.1 Using the 3RS25 analog device to implement a simple 2-step controller.............................. 71
10.2 Using the digital device to implement a simple 2-step controller with simultaneous output
of an alarm value............................................................................................................... 72
10.3 Using the digital device to implement a simple 3-step controller with simultaneous output
of an alarm value............................................................................................................... 73
11 Connection........................................................................................................................................... 75
11.1 Warning notices................................................................................................................. 75
11.2 General information........................................................................................................... 75
11.3 Connection data for terminals ............................................................................................ 76
11.4 Terminal assignment.......................................................................................................... 76
11.5 Connection tool ................................................................................................................. 78
11.6 Connecting the screw terminals ......................................................................................... 79
11.7 Disconnecting screw terminals........................................................................................... 80
11.8 Wiring rules for spring-type terminals (with push-in technology)......................................... 80
11.9 Connect the spring-type terminal (push-in) ........................................................................ 81
11.10 Disconnect the spring-type terminal (push-in) .................................................................... 82
11.11 Attaching the terminals...................................................................................................... 83
11.12 Removing the terminals ..................................................................................................... 84
11.13 Connection of thermocouples and resistance sensors ......................................................... 85
12 Mounting ............................................................................................................................................. 87
12.1 Warning notices................................................................................................................. 87
12.2 Mounting position, installation width/overall depth, layout................................................. 87
12.3 Terminal coding ................................................................................................................. 88
12.4 Mounting on a standard rail ............................................................................................... 88
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12.5 Disassembling from a standard mounting rail ..................................................................... 89
12.6 Mounting on a level surface ............................................................................................... 90
12.7 Disassembling from a level surface..................................................................................... 91
13 Technical data...................................................................................................................................... 93
13.1 Technical data in Siemens Industry Online Support............................................................. 93
13.2 Insulation concept of the plant........................................................................................... 93
14 CAx data .............................................................................................................................................. 97
14.1 CAx data types................................................................................................................... 97
14.2 CAx data............................................................................................................................ 97
15 Spare parts/accessories........................................................................................................................ 99
15.1 Overview........................................................................................................................... 99
15.2 Terminals......................................................................................................................... 100
15.3 Device fusing................................................................................................................... 100
16 Process data and data sets................................................................................................................. 101
16.1 Data sets - structure ......................................................................................................... 101
16.2 Data sets - Overview ........................................................................................................ 101
16.3 Process image output (PIQ) and input (PII)........................................................................ 102
16.4 Identi󹪝cation data............................................................................................................ 103
16.5 Data set 92 - Diagnostics.................................................................................................. 104
16.6 Data set 94 - measured values.......................................................................................... 106
16.7 Data set 95 - measured values (󹪞oating-point format) ...................................................... 107
16.8 Data set 131 - parameters ................................................................................................ 107
Glossary ............................................................................................................................................. 113
Index .................................................................................................................................................. 117
Table of contents
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Introduction 1
1.1 Required basic knowledge
Basic knowledge of low-voltage industrial controls is required to understand this manual.
WARNING
Quali󹪝ed personnel required
All work involved in connecting, commissioning, and maintenance must be performed
by quali󹪝ed, responsible personnel.
Improper handling may result in serious personal injury and considerable damage to
property.
1.2 Scope of the manual
Scope of the manual
The manual is valid for these monitoring relays. This manual contains a description of the
devices that are valid at the time of publication.
1.3 Operating Instructions
To install and connect the monitoring relays, you require the operating instructions of the
monitoring relays used. You can 󹪝nd the operating instructions under Operating instructions
(https://www.siemens.com/sirius/manuals) in the Industry Online Support.
1.4 Siemens Industry Online Support
Information and service
At Siemens Industry Online Support you can obtain up-to-date information from our global
support database:
• Product support
• Application examples
• Forum
• mySupport
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Link: Siemens Industry Online Support (https://support.industry.siemens.com/cs/de/en)
Product support
You can 󹪝nd information and comprehensive know-how covering all aspects of your product
here:
•FAQs
Answers to frequently asked questions
•Manuals/operating instructions
Read online or download, available as PDF or individually con󹪝gurable.
•Certi󹪝cates
Clearly sorted according to approving authority, type and country.
•Characteristics
For support in planning and con󹪝guring your system.
•Product announcements
The latest information and news concerning our products.
•Downloads
Here you will 󹪝nd updates, service packs, HSPs and much more for your product.
•Application examples
Function blocks, background and system descriptions, performance statements,
demonstration systems, and application examples, clearly explained and represented.
•Technical data
Technical product data for support in planning and implementing your project
Link: Product support (https://support.industry.siemens.com/cs/ww/en/ps)
mySupport
The following functions are available in your personal work area "mySupport":
•Support Request
Search for request number, product or subject
•My 󹪝lters
With 󹪝lters, you limit the content of the online support to di󹪜erent focal points.
•My favorites
With favorites you bookmark articles and products that you need frequently.
•My noti󹪝cations
Your personal mailbox for exchanging information and managing your contacts. You can
compile your own individual newsletter in the "Noti󹪝cations" section.
•My products
With product lists you can virtually map your control cabinet, your system or your entire
automation project.
•My documentation
Con󹪝gure your individual documentation from di󹪜erent manuals.
Introduction
1.4 Siemens Industry Online Support
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•CAx data
Easy access to CAx data, e.g. 3D models, 2D dimension drawings, EPLAN macros, device
circuit diagrams
•My IBase registrations
Register your Siemens products, systems and software.
1.5 Siemens Industry Online Support app
Siemens Industry Online Support app
The Siemens Industry Online Support app provides you access to all the device-speci󹪝c
information available on the Siemens Industry Online Support portal for a particular article
number, such as operating instructions, manuals, data sheets, FAQs etc.
The Siemens Industry Online Support app is available for Android and iOS:
Android iOS
1.6 Support Request
After you have registered, you can use the Support Request form in the online support to send
your question directly to Technical Support:
Support Request: Internet (https://support.industry.siemens.com/My/ww/en/requests)
1.7 Security information
Siemens provides products and solutions with industrial security functions that support the
secure operation of plants, systems, machines and networks.
In order to protect plants, systems, machines and networks against cyber threats, it is necessary
to implement – and continuously maintain – a holistic, state-of-the-art industrial security
concept. Siemens’ products and solutions constitute one element of such a concept.
Customers are responsible for preventing unauthorized access to their plants, systems,
machines and networks. Such systems, machines and components should only be connected to
Introduction
1.7 Security information
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an enterprise network or the internet if and to the extent such a connection is necessary and only
when appropriate security measures (e.g. 󹪝rewalls and/or network segmentation) are in place.
For additional information on industrial security measures that may be implemented, please
visit
https://www.siemens.com/industrialsecurity.
Siemens’ products and solutions undergo continuous development to make them more secure.
Siemens strongly recommends that product updates are applied as soon as they are available
and that the latest product versions are used. Use of product versions that are no longer
supported, and failure to apply the latest updates may increase customer’s exposure to cyber
threats.
To stay informed about product updates, subscribe to the Siemens Industrial Security RSS Feed
under
https://www.siemens.com/industrialsecurity.
1.8 Recycling and disposal
These devices can be recycled thanks to their low pollutant content.
Note
For environmentally friendly recycling and disposal of your old device, contact a company
certi󹪝ed for the disposal of electronic waste and dispose of the device in accordance with the
regulations in your country.
Introduction
1.8 Recycling and disposal
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Safety instructions, standards 2
2.1 Product-speci󹪝c safety instructions
2.1.1 Hazardous Voltage
Hazardous Voltage
WARNING
Hazardous Voltage.
Will cause death or serious injury.
Turn o󹪜 and lock out all power supplying the system and device before working on the device.
WARNING
Commissioning by electrician required
The 3RS2 temperature monitoring relay has protection class II and must be commissioned only
by an authorized electrician.
2.1.2 Intended use
Intended Use
WARNING
Can Cause Death, Serious Injury, or Property Damage.
The devices may only be used for the applications described in the catalog and the technical
description, and only in conjunction with equipment or components from other manufacturers
which have been approved or recommended by Siemens.
This product can function correctly and reliably only if it is transported, stored, assembled, and
installed correctly, and operated and maintained as recommended.
Before you run any sample programs or programs that you have written yourself, make sure
that running the plant cannot cause injury to anyone else or damage to the machine itself.
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Note
Safe state
The basis of the safety function is the de󹪝nition of the safe state.
In the case of temperature monitoring relays, this is the "OFF state", i.e. an open contact for
sensors or shutdown of the actuators.
2.1.3 Radio interference
Radio interference
NOTICE
The 3RS2 devices, except digital devices with IO-Link 3RS2800, are certi󹪝ed as devices of
classes A (industrial environment) and B (residential environment).
The digital devices with IO-Link 3RS2800, are certi󹪝ed as class A devices. The use of these
devices can lead to radio interference in residential areas!
2.2 Standards, approvals and certi󹪝cates
Applicable standards
The temperature monitoring relays meet the requirements of the following standards:
Table 2-1 Standards ‑ monitoring relays
Device standards • IEC / EN 60947-1 "Low-voltage switchgear and controlgear: General rules"
• IEC / EN 60947-5-1 "Control circuit devices and switching elements: Electromechanical control
circuit devices"; VDE 0660 "Low-voltage switchgear"
• DIN EN 50042 "Terminal marking"
EMC standard • IEC / EN 61000-6-2 "Generic standard Immunity"
• IEC / EN 61000-6-4 "Generic standard emission"
Resistance to extreme cli‐
mates
• IEC 60721-3-3 "Classi󹪝cation of environmental conditions"
The monitoring relays are climate-proof according to IEC 60721-3.
Safety instructions, standards
2.2 Standards, approvals and certi󹪝cates
3RS2 temperature monitoring relay
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Touch protection • IEC / EN 60529 "Degrees of protection provided by enclosures"
Monitoring relays are safe to touch in accordance with IEC / EN 60529.
Safety standards • IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related
systems
• IEC 62061: Safety of machinery – Functional safety of safety-related electrical, electronic and
programmable electronic control systems
• ISO 13849: Safety of machinery – Safety-related parts of control systems
• IEC 14597: Temperature control devices and temperature limiters for heat generating systems
• IEC 50495: Safety devices required for the safe functioning of equipment with respect to ex‐
plosion risks
• IEC 50156: Electrical equipment for furnaces and ancillary equipment
Approvals and certi󹪝cates
SIRIUS components have been approved by various di󹪜erent bodies (e.g. shipbuilding). The
current list of approvals is provided in Chapter 10 of the catalog Catalog IC 10 (https://
support.industry.siemens.com/cs/ww/en/view/109747945). You can 󹪝nd more information
and certi󹪝cates for download at Internet (https://support.industry.siemens.com/cs/ww/en/ps/
16027/cert).
Safety instructions, standards
2.2 Standards, approvals and certi󹪝cates
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Safety instructions, standards
2.2 Standards, approvals and certi󹪝cates
3RS2 temperature monitoring relay
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ATEX 3
3.1 Safety and commissioning instructions for hazardous areas
Carefully observe the following information and standards where there is an increased level of
danger in hazardous areas:
• EN 60079-14/VDE 0165-1 for electrical apparatus for explosive gas atmospheres
• EN 60079-17 Inspection and maintenance of electrical installations in hazardous areas
• EN 50495 Safety devices required for the safe functioning of equipment with respect to
explosion risks
Types of protection:
• Dust:
– Protection by enclosure "t", EN 60079-31
– Pressurized enclosure "p", EN 60079-2
– Protection by encapsulation "m", EN 60079-18
– Control of ignition sources "b", EN 80079-37 Liquid immersion "k", EN 80079-37 Special
protection "s", EN 60079-33
• Gas:
– Flameproof enclosures "d", EN 60079-1
– Increased safety "eb", EN 60079-7
– Pressurized enclosure "p", EN 60079-2
– Encapsulation "m", EN 60079-18
– Powder 󹪝lling "q", EN 60079-5
– Oil immersion "o", EN 60079-6
– Control of ignition sources "b", EN 80079-37 Liquid immersion "k", EN 80079-37 Special
protection "s", EN 60079-33
DANGER
Operate these devices outside the ATEX zone only!
These devices do not have explosion protection type "i" (intrinsic safety). For this reason, they
must only ever be used outside the hazardous (ATEX) zone.
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Note
The intended use of the devices is permitted in systems for industrial applications in hazardous
areas up to Zone 1 (gas, vapors, fog) or Zone 21 (dust).
ATEX marking:
• Dust: [b1] [Ex h] [pyb] [tb] [mb] [kb] [sb] III C Db
• Gas: [b1] [Ex h] [db] [eb] [pyb] [mb] [ob] [q] [kb] [sb] II C Gb
3.2 Use in areas subject to an explosion hazard due to gases or dust
Requirements for use in hazardous areas
The device is tested in accordance with the ATEX Directive 2014/34/EU and is also certi󹪝ed for
use in accordance with DIN EN 50495 of the ATEX Directive. It monitors hazardous gas or dust
atmospheres. In addition, the device meets the requirements of DIN EN 61508 and
DIN EN 13849 (SIL 1 / PL c).
All components and their corresponding circuitry which belong to the critical sequence of the
analog input 4 mA to 20 mA (exists on the sensor expansion module) have ATEX certi󹪝cation.
Note
This means you always need a sensor expansion module 3RS29 to use ATEX applications.
ATEX
3.2 Use in areas subject to an explosion hazard due to gases or dust
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Analog devices 4
4.1 Applications
The analog devices are used, for example, for shutdown in case speci󹪝ed limit temperatures are
exceeded, for output of alarm messages or simply as a two-step controller.
They are used in the following applications and more:
• Protection of plants and the environment
• Exhaust temperature monitoring
• Temperature monitoring in control cabinets
• Frost monitoring
• Temperature limits for process variables
• Control of plants and machinery
• Motor monitoring
• Bearing monitoring
• Gear oil monitoring
• Monitoring of coolants
• Packaging industry
• Electroplating
• Air-conditioning systems
• Ventilation systems
• Solar collectors
• Heat pumps
• Hot water supply
• Panel building
• Rail
• Shipbuilding
4.2 General functions
The temperature monitoring relays record the temperature with the aid of temperature sensors
immersed in the medium. The temperature is evaluated by the device and monitored for
overshoot or undershoot of a limit.
The analog devices have an adjustable limit value. They are operated according to the closed-
current principle.
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The following settings can be made using a screwdriver on the front panel of the device:
• Tripping value
• Sensor type
• Measuring range
• Hysteresis
• Overshoot / undershoot
See Chapter Operator controls and display elements, settings, measuring ranges (Page 21).
Power supply:
The devices are operated with a control voltage of between 24 V AC/DC and 240 V AC/DC,
depending on the version.
4.3 Performance characteristics
Table 4-1 Performance features of analog device 3RS2500
Adjustable Yes
Connectable sensor type • Thermocouple
• Resistance sensor (two-wire and three-wire measurement)
Resistance sensors (see also Resistance sensors
(Page 69))
Pt100
Thermocouples (see also Thermocouples
(Page 67))
• Type J
• Type K
Number of sensors that can be monitored 1
Adjustable hysteresis values 5%, 10%, 15%, 20%
Number of adjustable limit values 1
Adjustable trip delay No
Adjustable monitoring Overshoot / undershoot
Restart Auto
Unit °C
4.4 Connection systems
The devices can be supplied with the connection systems detailed below:
• Screw terminals
• Spring-type terminals (push-in)
Analog devices
4.4 Connection systems
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4.5 Sensor types
The analogically adjustable temperature monitoring relays support the connection of the
following types of sensor, depending on the version:
• Resistance sensors Pt100 (monitoring for overshoot and undershoot) For more detailed
information, refer to Chapter "Resistance sensors (Page 69)".
• Thermocouples
– Type J (monitoring for overshoot and undershoot)
– Type K (monitoring for overshoot and undershoot)
For more detailed information, refer to Chapter Thermocouples (Page 67).
4.6 Measuring ranges
Table 4-2 Measuring ranges of the analog devices
Measuring
range
Switch position of the potentiometer for setting the measured value ϑ1
Min 1/2 Max
0 °C ... +100 °C 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C
0 °C ... +200 °C 0 °C 20 °C 40 °C 60 °C 80 °C 100 °C 120 °C 140 °C 160 °C 180 °C 200 °C
0 °C ... +600 °C 0 °C 60 °C 120 °C 180 °C 240 °C 300 °C 360 °C 420 °C 480 °C 540 °C 600 °C
+500 °C ... +1000
°C
500 °C 550 °C 600 °C 650 °C 700 °C 750 °C 800 °C 850 °C 900 °C 950 °C 1000 °C
-50 °C ... +50 °C -50 °C -40 °C -30 °C -20 °C -10 °C 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C
Measuring ranges of the sensors:
• Pt100 resistance sensors:
– -50 °C ... +50 °C
– 0 °C ... +100 °C
– 0 °C ... +200 °C
• Thermocouples:
– 0 °C ... +200 °C
– 0 °C ... +600 °C
– +500 °C ... +1000 °C
Changes in temperature over time can be found in the time diagrams (see Chapter Time
diagrams (Page 22)).
Analog devices
4.6 Measuring ranges
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4.7 Temperature monitoring
Temperature monitoring curve
If the temperature reaches the set limit ϑ1, the output relay K1 (change-over contact) will
change its switching state.
The output relays return immediately to their original state once the temperature reaches the
respective hysteresis value.
The limit ϑ1 is set for overshoot or undershoot to be monitored.
The cable length of the sensors can be compensated for with three-wire measurement up to a
maximum cable resistance of ... ohm.
Analog devices
4.7 Temperature monitoring
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