GESTRA LRGT 16-3 Installation instructions

Installation & Operating Manual
Conductivity Transmitter
LRGT 16-3
LRGT 16-4
LRGT 17-3
819877-01
EN
English

2LRGT 1x-x - Installation & Operating Manual - 819877-01
Contents
Content of this Manual................................................................................................................................... 4
Scope of delivery/Product package............................................................................................................... 4
How to use this Manual.................................................................................................................................. 5
Illustrations and symbols used...................................................................................................................... 5
Hazard symbols in this Manual...................................................................................................................... 5
Types of warning ............................................................................................................................................ 6
Specialist terms/Abbreviations...................................................................................................................... 7
Usage for the intended purpose..................................................................................................................... 8
Admissible system components, dependent on the required safety integrity level ......................................8
Improper use .................................................................................................................................................. 9
Basic safety notes .......................................................................................................................................... 9
Required personnel qualifications............................................................................................................... 10
Notes on product liability............................................................................................................................. 10
Functional safety, safety integrity level (SIL) .............................................................................................. 11
Check the secure current output regularly................................................................................................11
Reliability data to EN 61508 ......................................................................................................................... 12
Function ........................................................................................................................................................ 13
Technical data .............................................................................................................................................. 15
Example name plate/Identification.............................................................................................................. 18
Factory settings............................................................................................................................................ 19
Overall view .................................................................................................................................................. 20
LRGT 16-3...............................................................................................................................................20
LRGT 16-4...............................................................................................................................................20
LRGT 17-3...............................................................................................................................................20
Dimensions of the LRGT 16-3....................................................................................................................... 22
Dimensions of the LRGT 16-4....................................................................................................................... 23
Dimensions of the LRGT 17-3....................................................................................................................... 24
Installation.................................................................................................................................................... 25
Additional notes for installation................................................................................................................ 26
Example, LRGT 16-3................................................................................................................................ 27
Detaching the terminal box from the electrode.........................................................................................28
Installation examples with dimensions....................................................................................................... 31
Conductivity measurement ......................................................................................................................31
Conductivity measurement and continuous blowdown control.................................................................. 32
Conductivity measurement and continuous blowdown control via a separate level pot.............................33
Key Fig. 12 to Fig. 14............................................................................................................................... 34
Aligning the terminal box............................................................................................................................. 34

3LRGT 1x-x - Installation & Operating Manual - 819877-01
Contents
Functional elements............................................................................................................................. 35
Electrical connection.................................................................................................................................... 36
Notes on electrical connection .................................................................................................................36
Connecting the 24V DC power supply .....................................................................................................36
Connecting the actual value output (4-20 mA)..........................................................................................36
Pin assignment of the M12 connector for non pre-wired control cables ...................................................36
Bringing into service .................................................................................................................................... 37
Changing the factory settings if necessary............................................................................................... 37
Changing parameters with password protection enabled .........................................................................37
Changing the cell constant....................................................................................................................... 41
Changing the temperature coefficient ...................................................................................................... 42
Using the “CAL” function..........................................................................................................................42
Using the “FiLt” feature............................................................................................................................43
Changing the scale of the 4-20 mA actual value output ...........................................................................43
Changing the display unit (µS/cm or ppm)................................................................................................ 45
Manually initiating a display test.............................................................................................................. 45
Viewing the signal reserve “SGnL” (for LRGT 16-4 only)........................................................................... 46
Viewing the software version and equipment type “Info”.......................................................................... 46
Enabling/disabling password protection................................................................................................... 46
Comparing the reading with the reference measurement of a reliable sample.......................................... 47
Starting, operation and testing .................................................................................................................... 48
System malfunctions.................................................................................................................................... 51
Causes ....................................................................................................................................................51
Indication of system malfunctions using error codes................................................................................52
Faults that do not provoke a shutdown.....................................................................................................55
Checking installation and function ...........................................................................................................56
Taking out of service/Disassembly.............................................................................................................. 57
Cleaning the measuring electrodes of the conductivity transmitter.......................................................... 58
Monthly comparison of readings .............................................................................................................58
Cleaning interval...................................................................................................................................... 58
Disposal ........................................................................................................................................................ 59
Returning decontaminated equipment........................................................................................................ 59
Declaration of Conformity; Standards and Directives................................................................................. 60

4LRGT 1x-x - Installation & Operating Manual - 819877-01
Content of this Manual
Product:
■ Conductivity Transmitter LRGT 16-3
■ Conductivity Transmitter LRGT 16-4
■ Conductivity Transmitter LRGT 17-3
First edition:
BAN 819877-00/09-2019cm
© Copyright
All rights reserved. Any misuse, particularly reproduction and dissemination to third parties, is not permitted.
The General Terms & Conditions of GESTRA AG apply.
Scope of delivery/Product package
■ 1 x conductivity transmitter LRGT 1x-x
■ 1 x sealing ring, D 33 x 39, form D, DIN 7603-2.4068, bright annealed
■ 1 x Installation & Operating Manual
Required accessories for LRGT 16-3, LRGT 17-3 and LRGT 16-4 when installing for the first time
■ Connecting cable, M12 A-coded, 5m, mat. no. 1508392
■ Connecting cable, M12 A-coded, 10m, mat. no. 1508394
■ Connecting cable, M12 A-coded, 30m, mat. no. 1508395
Optional accessories or refit
■ Cable jack M12 A-coded, mat. no. 52820

5LRGT 1x-x - Installation & Operating Manual - 819877-01
How to use this Manual
This Installation & Operating Manual describes how to correctly use LRGT 16-3, LRGT 16-4 and
LRGT 17-3 conductivity transmitters. It applies to all persons who integrate this equipment into control
systems, install, bring into service, operate, maintain and dispose of this equipment. Anyone carrying out
the above-mentioned activities must have read this Installation & Operating Manual and understood its
contents.
■ Read this Manual in full and follow all instructions given.
■ Please also read the instructions for use of any accessories.
■ The Installation & Operating Manual is part of the product package. Keep it in an easily accessible
location.
Availability of this Installation & Operating Manual
■ Make sure that the Installation & Operating Manual is always available to the operator.
■ If you pass on or sell the equipment to a third party, please also hand over the Installation & Operating
Manual.
Hazard symbols in this Manual
Danger zone / Dangerous situation
Danger of death from electric shock
Illustrations and symbols used
1. Action to be taken
2.
■ Lists
◆ Bullet points in lists
A Keys to illustrations
Additional
information
Read the relevant
Installation & Operating Manual
+
-
Press the rotary knob

6LRGT 1x-x - Installation & Operating Manual - 819877-01
Types of warning
DANGER
Warning of a dangerous situation that will result in death or serious injury.
WARNING
Warning of a dangerous situation that may possibly result in death or serious injury.
CAUTIONCAUTION
Warning of a situation that may result in minor or moderate injury.
ATTENTION
Warning of a situation that will result in damage to property or the environment.

7LRGT 1x-x - Installation & Operating Manual - 819877-01
Specialist terms/Abbreviations
Here, we explain some abbreviations, specialist terms, etc., which are used in this Manual.
IEC 61508
International standard IEC 61508 describes both the type of risk assessment and actions taken to provide
appropriate safety functions.
SIL (safety integrity level)
Safety integrity levels SIL 1 to 4 are used to quantify risk reduction. SIL 4 is the highest level of risk reduction.
International standard IEC 61508 forms the basis for establishing, testing and operating technical safety
systems.
LRGT .. / LRR .. / URS .. / URB .. / SRL .. / etc.
Equipment and type designations of GESTRA AG.
SELV
Safety Extra Low Voltage
Operating point (of the system)
The operating point describes the operating parameters at which a system or boiler is operated in
the nominal range. In a steam boiler, for example, these parameters would be output, capacity, pressure
and temperature.
The pressure at the operating point does not have to match the design pressure, but is the same or lower.

8LRGT 1x-x - Installation & Operating Manual - 819877-01
Usage for the intended purpose
LRGT 16-3, LRGT 16-4 and LRGT 17-3 conductivity transmitters can be used as conductivity limiters
and continuous blowdown controllers to continually monitor conductivity in steam boilers and hot water
installations. They present a linear profile of conductivity in a preset measuring range via a 4-20mA
current output.
■ The transmitter’s secure 4-20 mA actual value output (SIL 2) can be used with a suitable conductivity
controller, as a continuous blowdown controller with MIN/MAX alarm, for example.
■ To ensure problem-free operation, pay attention to the requirements for water quality as
specified in the technical rules (TRD) and EN standards for steam boiler plants.
■ The equipment may only be used within the admissible pressure and temperature ratings, see
“Technical data” on page 15 and “Example name plate/Identification” on page 18.
Admissible system components, dependent on the required safety integrity level
In accordance with standards EN12952, EN12953, IEC61508 and the technical rules of VdTÜV Bulletin
BP WAUE 0100-RL, the conductivity electrode can be operated with safety integrity level SIL 2.
If an electronic control unit (diagnostic tester) that also has a SIL 2 rating is connected to the 4-20mA
output, the entire event chain system can be operated at this safety integrity level.
A diagnostic tester with a higher SIL rating does not increase the safety of the overall system.
The maximum achievable safety level is dictated by the lowest SIL rating of a participant in the
event chain as a whole.
Systems without SIL rating
In systems without a SIL rating, any controller, display unit or diagnostic tester with an input for a stand-
ard 4-20 mA signal can be connected.
To ensure the proper use of equipment during all types of use, please also read the Installation
& Operating Manuals for the system components used.
■ You can find the latest Installation & Operating Manuals for other system components on our
website: www.gestra.com

9LRGT 1x-x - Installation & Operating Manual - 819877-01
Improper use
There is a danger of death due to explosion if the equipment is used in potentially explo-
sive atmospheres.
Do not use the equipment in potentially explosive atmospheres.
Do not bring any equipment into service that does not have its own specific name plate.
The name plate indicates the technical features of the equipment.
Basic safety notes
Danger to life from scalding if the conductivity electrode is removed under pressure.
Steam or hot water can spurt forcefully out of the equipment.
■ Only remove the conductivity electrode at a boiler pressure of 0 bar.
Risk of severe burns when working on a conductivity electrodes that has not been
allowed to cool. The conductivity electrode becomes very hot during operation.
■ Always allow conductivity electrodes to cool.
■ Perform all installation and maintenance work only when the conductivity electrode has
been allowed to cool.
There is a risk of electric shock during work on electrical systems.
■ Always switch off the voltage to the plant before performing connection work.
■ Check that the plant is not carrying live voltage before commencing work.
Danger to life from a faulty LRGT 1x-x conductivity electrode due to the sudden escape of
hot steam or hot water.
Jolts or impacts during transport or installation can damage the conductivity
electrode, causing pressurised hot steam or hot water to escape through the pressure relief
hole.
■ To prevent damage during transport and installation, do not expose the electrode
rods to hard impacts.
■ Before and after installation, check that the conductivity electrode is undamaged.
■ When bringing the conductivity electrode into service, check that it is not leaking.
Attempts to repair the equipment will cause the plant to become unsafe.
■ The LRGT 1x-x conductivity electrode may only be repaired by the manufacturer, GESTRA AG.
■ Only replace faulty equipment with identical equipment from GESTRA AG.

10 LRGT 1x-x - Installation & Operating Manual - 819877-01
Basic safety notes
A lack of proper maintenance and cleaning can result in damage to the conductivity
electrode and/or false measurement results and warning messages.
■ Check the conductivity electrode once a year by performing comparative measurements. If
the “CF” (cell constant) value of 003.0 is exceeded after recalibration, the warning message
“CF.Hi” will appear.
■ Adhere to the maintenance and cleaning intervals, see page 58.
Required personnel qualifications
Activity Personnel
Integration in control system Specialist staff Plant designer
Installation/electrical
connection/bringing into service Specialist staff
The unit is an item of equipment with a
safety function (EU Pressure Equipment
Directive) and may only be installed, electri-
cally connected and brought into service by
suitable, trained staff.
Company Boiler service technician Staff trained by the plant operator.
Maintenance work Specialist staff
Maintenance and refits may only be
performed by authorised staff who have
undergone specific training.
Refits Specialist staff Persons trained by the plant operator to work
with pressure and temperature.
Fig. 1
Notes on product liability
We the manufacturer cannot accept any liability for damages resulting from improper use of the equip-
ment.

11LRGT 1x-x - Installation & Operating Manual - 819877-01
Functional safety, safety integrity level (SIL)
LRGT 16-3, LRGT 16-4 and LRGT 17-3 conductivity transmitters have a secure 4-20 mA actual value
output (SIL 2). If an electronic control unit (diagnostic tester) that also has a SIL 2 rating is connected to
the 4-20mA output, the entire event chain system can be operated at this safety integrity level.
When combined with the accessories, you will have a type B subsystem in accordance with IEC 61508.
The technical and safety characteristics in Fig. 2 below are based solely on LRGT 16-3, LRGT 16-4 and
LRGT 17-3 conductivity transmitters.
Check the secure current output regularly
Once a year, check that conductivity transmitters are functioning correctly by initiating the test function
(T1 = 1 year).
The test function is initiated on site using the rotary knob integrated in the terminal box, see page 50.

12 LRGT 1x-x - Installation & Operating Manual - 819877-01
Reliability data to EN 61508
Description Characteristic values
Type of electrode LRGT 1x-3 LRGT 16-4
Safety integrity level SIL 2 SIL 2
Architecture 1oo1 1oo1
Type of equipment Type B Type B
Hardware fault tolerance HFT = 0 HFT = 0
Overall failure rate for dangerous undetected
failures λDU = < 50 * 10-8 1/h λDU = < 50 * 10-8 1/h
Overall failure rate for dangerous detected
failures λDD = < 5000 * 10-9 1/h λDD = < 5000 * 10-9 1/h
Safe failure fraction SFF > 95.0% SFF > 90.0%
Test interval T1 = 1 year T1 = 1 year
Probability of failure on demand PFD < 50 * 10-4 PFD < 50 * 10-4
Diagnostic coverage Percentage of dangerous
failures detected by a test. DC > 90.0% DC > 85.0%
Mean time to failure MTTFd> 30 a MTTFd> 30 a
Mean time to failure MTTF > 10 a MTTF > 10 a
Diagnostic interval T2 = 1 hour T2 = 1 hour
Performance level (to ISO 13849) PL = d PL = d
Probability of failure per hour PFH < 50 * 10-8 1/h PFH < 50 * 10-8 1/h
Ambient temperature as a basis for calculation Tu = 60 °C Tu = 60 °C
Mean time to repair MTTR = 0
(no repair)
MTTR = 0
(no repair)
Fraction of undetected dangerous failures that
have a common cause beta = 2% beta = 2%
Fraction of detected dangerous failures that
have a common cause beta d = 1% beta d = 1%
Fig. 2

13LRGT 1x-x - Installation & Operating Manual - 819877-01
Function
The equipment measures the electrical conductivity of electrically conductive fluids and converts the infor-
mation into a conductivity-dependent 4-20 mA current signal.
Measuring process of the LRGT 16-3 and LRGT 17-3
LRGT 16-3 and LRGT 17-3 conductivity transmitters use the conductometric two-electrode measuring
process. A measuring current with a suitable frequency for the measuring range is introduced into the
fluid. This produces a potential gradient between the electrode and the measuring tube, which is analysed
as a measuring voltage.
Measuring process of the LRGT 16-4
The LRGT 16-4 conductivity transmitter uses the conductometric four-electrode measuring process. It
consists of two current and two voltage electrodes. The current electrodes introduce a measuring current
with a fixed frequency into the fluid. This gives rise to a potential gradient between these electrodes. This
potential gradient is then picked up by the voltage electrodes and analysed as measuring voltage.
Temperature compensation of readings based on a reference temperature (25°C)
The electrical conductivity changes as a function of the temperature. In order to base the readings on a
reference temperature, an integrated resistance thermometer measures the temperature of the fluid. The
electrical conductivity is calculated from the measuring current and measuring voltage, and then based
on the reference temperature of 25°C through temperature compensation.
Compensation process
Based on a set temperature coefficient, the conductivity reading is corrected to form a linear character-
istic. The coefficient (default 2.1% per °C) is normally used for steam generating units with a constant
pressure. Conductivity is established for a fluid temperature of 25°C.
The gradient is then verified at service pressure using a calibrated conductivity meter.
Transmitter function
The transmitter function is the ability of the electrode to provide a scalable measuring range on the 4-20
mA current output interface and to make this available to one or more recipients for analysis.
This equipment does not have any controlling or limiting functions.
Automatic self-test
An automatic self-test periodically monitors the safety and function of the conductivity transmitters and
measured value acquisition.
Faults in the electrical connection or electronic measuring equipment trigger a fault indication on the
display, and the current output is set to 0mA.

14 LRGT 1x-x - Installation & Operating Manual - 819877-01
Function
Indications and signals, see page 48 / 52 *
LRGT 1x-x conductivity transmitters feature a green 4-digit, 7-segment display for showing readings,
status information and error codes. The operating status is indicated by one red and three green LEDs.
Behaviour when switched on *
The display alternately shows the software version, the type and then the measured conductivity.
Behaviour in normal operation (no faults) *
The display shows the measured conductivity value (4 digits), e.g. 1550, and converts this value into a
current signal from 4-20 mA, in accordance with the predefined measuring range (see page 43, Sout
parameter).
Behaviour in the event of malfunctions *
The error state or malfunction is shown on the display by an error code, e.g. E.005 (error codes see page
52).
Every time there is a fault, 0 mA is output via the current output.
Faults are displayed based on their priority. Indications with higher priority are shown conti-
nuously before those with low priority. If several indications need attention, the display does not
alternate between them.
Electrode faults cannot be acknowledged.
When the fault is corrected, the indication also disappears from the display, and the LRGT 16-3,
LRGT 17-3 or LRGT 16-4-conductivity transmitter returns to normal operation.
Behaviour when performing the test function *
Initiating the test function by pressing the rotary knob on the LRGT 1x-x causes the maximum output cur-
rent of 20 mA to be output. This enables you to check the effect of limit violation on connected diagnostic
testers.
* The tables on page 48 ff. clearly show the relationship between
the equipment status, the display and the status LEDs.
Setting parameters and changing factory settings
If necessary, you can adapt the electrode parameters to suit on-site conditions at the plant. You can set
parameters and change factory settings using a rotary knob on the terminal box, see page 38 ff.

15LRGT 1x-x - Installation & Operating Manual - 819877-01
Technical data
Model and mechanical connection
■ LRGT 16-3, LRGT 16-4, LRGT 17-3 Thread G1 A, EN ISO 228-1, see Fig. 6, 8 and 9
Nominal pressure rating, admissible service pressure and temperature
■ LRGT 16-3 PN 40 32 bar (abs) at 238 °C
■ LRGT 16-4 PN 40 32 bar (abs) at 238 °C
■ LRGT 17-3 PN 63 60 bar (abs) at 275 °C
Materials
■ Terminal box 3.2581 G AlSi12, powder-coated
■ Sheath 1.4301 X5 CrNi 18-10
■ Measuring electrodes 1.4571 X6CrNiMoTi17-12-2
■ Electrode insulation PTFE
■ Screw-in body:
◆ Measuring tube/screw of
LRGT 16-3, LRGT 17-3 1.4571, X6CrNiMoTi17-12-2
◆ Spacer disc of
LRGT 16-3, LRGT 16-4, LRGT 17-3 PEEK
Available electrode lengths (do not shorten)
■ LRGT 16-3, LRGT 17-3 200, 300, 400, 500, 600, 800, 1000 (mm)
■ LRGT 16-4 180, 300, 380, 500, 600, 800, 1000 (mm)
Temperature sensor
■ Resistance thermometer Pt 1000
■ Fluid temperature measuring range 0 to 280 °C
Conductivity range at 25 °C
■ LRGT 16-3, LRGT 17-3 0.5 μS/cm to 6000 μS/cm, 0.25 - 3000 ppm *
◆ Preferred measuring range up to 1000 µS/cm
■ LRGT 16-4 50 μS/cm to 10,000 μS/cm, 25 - 5000 ppm *
◆ Preferred measuring range from 500 µS/cm
* Conversion of µS/cm to ppm (parts per million): 1 μS/cm = 0.5 ppm
Measuring cycle
■ 1 second

16 LRGT 1x-x - Installation & Operating Manual - 819877-01
Technical data
Measurement quality (figures for value ranges between the on-site calibration points)
■ LRGT 1x-3
Resolution for internal processing * Measurement error Linearity error
◆ Range 1: 0.5 µS - 10 µS 7% 2%
◆ Range 2: 10 µS - 250 µS 3% 2%
◆ Range 3: 250 µS - 2600 µS 3% 1%
◆ Range 4: 2600 µS - 21000 µS 3% 1%
■ LRGT 16-4
Resolution for internal processing * Measurement error Linearity error
◆ Range 1: 10 µS - 100 µS 2% 2%
◆ Range 2: 100 µS - 2000 µS 2% 1.5%
◆ Range 3: 2000 µS - 50000 µS 2% 1%
* Resolution for internal processing based on 15 bits with plus or minus sign (16 bits).
The above figures refer to the uncompensated conductivity.
Time constant “T” (measured using the two-bath process)
Temperature Conductivity
■ LRGT 16-3, LRGT 17-3 9 seconds 14 seconds
■ LRGT 16-4 11 seconds 19 seconds
Temperature compensation
■ The temperature compensation process is linear and can be set via parameter tC, see page 42.
Supply voltage
■ 24 V DC ±20%
Power consumption
■ Max. 7 W
Current input
■ Max. 0.35 A
Internal fuse
■ T2A
Safety cutout at excessive temperature
■ Cutout occurs when an excessive temperature of 75 °C is measured in the electrode tip
Electrode voltage
■ < 500 mV (RMS) at no load

17LRGT 1x-x - Installation & Operating Manual - 819877-01
Technical data
Analogue output
■ 1 x actual value output 4-20 mA
■ Max. output load 500 Ω
■ M12 connector, 5-pole, A-coded
Indicators and controls
■ 1 x 4-digit green 7-segment display for showing readings and status information
■ 1 x red LED for indicating an error state
■ 3 x green LEDs for indicating the unit μS/cm / ppm and OK status
■ 1 x rotary knob IP65 with button for menu navigation and test function
Protection class
■ III Safety Extra Low Voltage (SELV)
IP rating to EN 60529
■ IP 65
Admissible ambient conditions
■ Service temperature: 0 °C – 70 °C
■ Storage temperature: - 40 °C – 80 °C
■ Transport temperature: - 40 °C – 80 °C
■ Air humidity: 10% – 95%, non-condensing
Weight
■ LRGT 16-3, LRGT 16-4, LRGT 17-3 approx. 2.1 kg

18 LRGT 1x-x - Installation & Operating Manual - 819877-01
Example name plate/Identification
Fig. 3
The date of production (quarter and year) is stamped on the screw-in body of each conductivity
transmitter.
A
A
Betriebsanleitung beachten!
See installation instruction!
Vor dem Öffnen des Deckels
Gerät freischalten!
Before removing cover
isolate from power supplies!
Tamb = °C (°F)T
bar (psi)
°C (°F)
L/H=
Pmax
Tmax
Tamb
GESTRA AG
Münchener Str.77
28215 Bremen
Made in Germany
1 Safety note
2 Equipment designation
3 Equipment function
4 Nominal pressure rating
5 Connection thread
6 Material of screw-in body
7 IP rating
8 Operating data (maximum pressure and temperature)
9 Supply voltage
0Power consumption
!Installed length in mm
"Measuring range in ppm
§Measuring range in µS/cm
$ Data interface
%Safety integrity level
&Type-approval number
/Conformity marking
(Disposal information
)Manufacturer
=Protection class
aMaterial number-serial number
1
2
3
4 5 6 7
8
9 0
!
&
(
)
a
/
=
$
%
"§

19LRGT 1x-x - Installation & Operating Manual - 819877-01
Factory settings
LRGT 1x-x conductivity transmitters are delivered ex works with the following settings:
Parameter Display in menu Unit
Parameter values
LRGT 16-3
LRGT 17-3 LRGT 16-4
Cell constant CF 0.210
Temperature coefficient tC % / °C 002.1
Filter constant (damping) FiLt seconds 0025
Scale of current output Sout µS 0500 7000
Display unit Unit µS
Password PW - - - oFF
Fig. 4

20 LRGT 1x-x - Installation & Operating Manual - 819877-01
OK
!
+
-
Overall view
Fig. 5
OK
!
+
-
A
B
C
D
F
J
LRGT 16-3 LRGT 16-4
I
G
E
H
K
LRGT 17-3
OK
!
+
-