GESTRA LRGS 15-1 User manual

1
EN
English
Conductivity Switch
LRGS 15-1
Original Installation Instructions
818758-02

2
Contents
Usage for the intended purpose ..............................................................................................................4
Safety note .............................................................................................................................................4
Danger ...................................................................................................................................................4
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility) .......................................................4
ATEX (Atmosphère Explosible).................................................................................................................4
Note on the Declaration of Conformity / Declaration by the Manufacturer ..........................................4
Important Notes
Page
Explanatory Notes
Scope of supply......................................................................................................................................5
Function .................................................................................................................................................5
Attention...............................................................................................................................................12
Note .....................................................................................................................................................12
Repositioning the terminal box..............................................................................................................13
Mounting conductivity switch LRGS 15-1..............................................................................................13
Tools ....................................................................................................................................................13
Installation
Technical Data
LRGS 15-1.......................................................................................................................................... 6, 7
Name plate / marking .............................................................................................................................8
Dimensions ............................................................................................................................................9
Key.......................................................................................................................................................11
LRGS 15-1 used as conductivity electrode............................................................................................14
LRGS 15-1 used for continuous blowdown control.......................................................................... 14, 15
Key.......................................................................................................................................................15
Examples of Installation
LRGS 15-1............................................................................................................................................10
Key.......................................................................................................................................................11
Functional Elements

3
Contents – continued –
Page
Fault finding list....................................................................................................................................23
Troubleshooting
Electrical Connection
LRGS 15-1............................................................................................................................................22
Operation
Danger .................................................................................................................................................24
Cleaning measuring electrode...............................................................................................................24
Exchanging the terminal box (with electronic insert)..............................................................................24
Cleaning measuring electrode, exchanging terminal box
Aligning the terminal box ......................................................................................................................16
Connecting conductivity switch LRGS 15-1...........................................................................................16
Attention...............................................................................................................................................17
Tools.....................................................................................................................................................17
Wiring diagram for conductivity switch LRGS 15-1................................................................................18
Commissioning
Keys and indicators ..............................................................................................................................19
Checking electrical connection .............................................................................................................19
Applying mains voltage.........................................................................................................................19
Factory settings ....................................................................................................................................20
Setting parameters ......................................................................................................................... 20, 21
Removing and disposing of conductivity switch ....................................................................................25
Note .....................................................................................................................................................25
Removing conductivity switch

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Important Notes
Safety note
Danger
When loosening the conductivity switch hot water or steam may escape. This presents
the risk of severe scalding.
Before removing the conductivity switch make sure that the boiler pressure is 0 bar.
The conductivity switch is hot during operation. This presents the risk of severe burns to
hands and arms. Before mounting, servicing or removing the equipment make sure that
it has cooled down to room temperatures.
The terminal strips of the conductivity switch LRGS 15-1 are live during operation.
This presents the danger of electric shock.
Cut off power supply to the equipment before mounting, removing or connecting the
terminal strips.
The equipment must only be installed by and commissioned by qualified and competent staff.
Retrofitting and maintenance work must only be performed by qualified staff who – through adequate
training – have achieved a recognised level of competence.
Usage for the intended purpose
The conductivity switch LRGS 15-1 must only be used for measuring the electrical conductivity in
liquids.
ATEX (Atmosphère Explosible)
According to the European Directive 2014/34/EU the equipment must not be used in potentially explo-
sive areas.
Note on the Declaration of Conformity / Declaration by the Manufacturer
For details on the conformity of our equipment according to the European Directives see our Declaration
of Conformity or our Declaration of Manufacturer.
The current Declaration of Conformity / Declaration of Manufacturer are available in the Internet under
www.gestra.de/documents or can be requested from us.
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility)
The equipment meets the requirements of the Low Voltage Directive 2014/35/EU and the
EMC Directive 2014/30/EU.

5
Function
The conductivity switch LRGS 15-1 is a compact system consisting of a conductivity monitoring
electrode and a conductivity switch integrated in the terminal box.
The LRGS 15-1 is used as limit switch and continuous blowdown controller in steam boilers.
The conductivity switch works according to the conductometric measuring method, continuously
sensing the electrical conductivity of the boiler water and thus taking a direct measurement of the
total dissolved solids (TDS).
The conductivity switch features an integrated 2-position controller for actuating a continuous
blowdown valve and automatic closing of the valve on boiler shut-down. Furthermore, an additional
adjustable contact outputs a signal when a limit is reached.
The electrical conductivity being a function of temperature, the measured value must be based on
a reference temperature of 25 °C. For calibration purposes a reference measurement (at 25 °C) is
therefore required.
If, however, a resistance thermometer (boiler water temperature) is applied, the adjustable
temperature coefficient can be used to compensate the obtained conductivity values. This means
that the conductivity reading will not be affected by variations in pressure and temperature.
Electrical conductivity is measured in units of microSiemens per centimeter (µS/cm). However, in
some countries the unit ppm (parts per million) is used. Conversion: 1 µS/cm = 0.5 ppm.
The conductivity switch can be switched to either µS/cm or ppm.
Explanatory Notes
Scope of supply
LRGS 15-1
1 Conductivity switch LRGS 15-1
1 Joint ring 27 x 32, form D, DIN 7603, 2.4068, bright annealed
1 Installation manual

6
LRGS 15-1
Service pressure
PN 25, 25 bar at 224 °C
Mechanical connection
Screwed ¾", EN ISO 228-1
Screwed ¾" NPT (optional)
Materials
Electrode body for screwing in place: 1.4571, X6CrNiMoTi17-12-2 or
1.4404, A 479 316 L (for NPT thread)
Measuring electrode: 1.4571, X6CrNiMoTi17-12-2
Electrode rod insulation: PTFE
Terminal box: Polycarbonate
Measuring length & length of installation
200, 300, 400, 500, 600, 800, 1000 mm
Input
1 Input for resistance thermometer, e. g. TRG 5-53, measuring insert Pt 100
Measuring range
100 to 10000 µS/cm at 25 °C or 50 to 5000 ppm at 25 °C
Setpoint
Adjustable between 100 and 10000 µS/cm or 50 to 5000 ppm
MAX limit
Adjustable between 100 and 10000 µS/cm or 50 to 5000 ppm
Switching hysteresis
Controller output: –10 % of the adjusted setpoint
MAX limit: –3 % of the adjusted MAX limit
Temperature coefficient Tk(if a resistance thermometer Pt 100 is connected)
1.6 – 3.0 % per °C, adjustable in steps of 0.1
Supply voltages
230 V, +10 / –15 %, 50-60 Hz
115 V, +10 / –15 %, 50-60 Hz (optional)
Power consumption
5 VA
Fuse
External slow-blow fuse, 63 mA at 230 V
External slow-blow fuse, 125 mA at 115 V
Output
3 Volt-free relay contacts, 5 A 230 V AC / 30 V DC cos ϕ= 1 (IEC 61810)
Provide contactor with inference suppressor (RC combination).
Contact material: AgNi 0.15
Technical Data

7
Technical Data – continued –
Indicators and adjustors
1 Four-digit, seven-segment indicator, red, for showing the actual value (X) / setpoint (W) and
status & malfunction messages
2 Amber LEDs for indicating the actual value (X) / setpoint (W)
1 Red LED for indicating the MAX limit
2 green LEDs for indicating “Valve OPEN / CLOSED”
4 Pushbuttons for parameter settings
Cable entry / Electric connection
Cable glands with integrated cable clamp, 3 x M 16 x 1.5
1 Four-pole screw-type terminal strip for mains connection
1 Three-pole screw-type terminal strip for connecting the continuous blowdown valve
1 Three-pole screw-type terminal strip for MAX limit
The terminal strips can be detached; conductor size 1.5 mm2
4 Terminal lugs for connecting the resistance thermometer
Protection
IP 65 to DIN EN 60529
Protection class
2 (protective insulation)
Weight
Approx. 1.5 kg
Environmental conditions:
Ambient temperature
when system is switched on: 0° ... 70 °C
during operation –10 ° ... 70 °C
Transport temperature
–20 ° ... +80°C (< 100 hours), defrosting time of the de-energized equipment before it can be put into
operation: 24 hours.
Storage temperature
–20 ° ... +70°C, defrosting time of the de-energized equipment before it can be put into operation:
24 hours.
Relative humidity
max. 95 %, no moisture condensation
Site altitude
max. 2000 m
LRGS 15-1 – continued –

8
Technical Data – continued –
Name plate / marking
Fig. 1
Equipment designation
Pressure class, thread type,
material number
Power rating
Disposal note
Measuring range
Manufacturer
Safety note
Admissible ambient
temperature
Before removing cover, isolate from
power supplies. See installation
instructions!
Avant d'ouvrir le couvercle
dèconnecter complètement l'appareil.
Voir instructions de montage.
Vor Öffnen des Deckels, Gerät
freischalten! Betriebsanleitung
beachten!
250 V ~T2A
230 VAC 50/60 Hz 5VA
Pmax
Tmax
LRGS 15-1
50-5000 ppm 100-10000 µS/cm
Leitfähigkeitsschalter
Conductivity Switch
Commutateur de conductibilité
GESTRA AG
Münchener Str.77
D-28215 Bremen
Phone:+49 (0) 421 / 3503-0
[email protected]
Tamb = 70°C (158 °F)
IP65
PN 25 G 1.4571
25 bar (363psi)
224°C (435°F)
/
34
Mat.-Nr.:XXXXXX
L: ____________ mm
Protection
Fuse for output contacts
Length of installation
Service pressure/temperature

9
C
Technical Data – continued –
Fig. 2
B
C
N
Dimensions
∅ 40
G ¾ ISO 228-1
RA 12.5
RA 3.2
0.5
180
367
40
O
D
E
129
O
A
F
G

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Functional Elements
Fig. 3
LRGS 15-1
5
7
2
1
6
3
4
Fig. 4
P8 P9 P10 P11
P7
P6
P5 P4
12
JL KKJ
MNLJ
I
H

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Dimensions / Functional Elements – continued –
1LED 1:The seven-segment indicator shows the setpoint
2LED 2: The seven-segment indicator shows the actual value
3LED 3: MAX limit reached
4LED 4: Continuous blowdown valve opens
5LED 5: Continuous blowdown valve in operating position
6Seven-segment indicator (indication of actual value or setpoint, temperature, error code)
7Pushbuttons
AGasket
BThermal insulation
CThread ¾"
DJoint ring 27 x 32, form D, DIN 7603, 2.4068, bright annealed
ELength of installation
FMeasuring electrode
GMeasuring surface
HCover screws (cross-recess head screws M4)
ICover
JFixing nut for terminal box
KTerminal lugs for resistance thermometer
LTerminal lugs for electrode lines
MTerminal strips
NCable glands 3 x M 16 x 1.5
OSealing plugs
Key

12
Installation
Attention
Do not bend the measuring electrode during installation.
Do not subject electrode to shocks.
Note that the measuring electrode of the conductivity switch must not be cut!
The conductivity switch is designed for installation in a boiler standpipe.
The seating surfaces and threads of the vessel standpipe or mounting flange must be
accurately machined.
Use only the supplied joint ring 27 x 32, form D, DIN 7603, 2.4068, bright annealed.
Do not insulate the thread with hemp or PTFE tape.
Do not include the terminal box in the thermal insulation of the boiler.
The conductivity switch can be mounted vertically or horizontally or with an inclina-
tion. The terminal box can be repositioned to ensure that the cable gland points in the
required direction.
Note that the measuring surface of the measuring electrode Fig. 2 must always be in
contact with the fluid.
Make sure that there is a distance of at least 50 mm between the measuring surface
and the boiler wall, the smoke tubes, other metallic installations and the min. water
level (LW).
The indicated torques for tightening must be observed without fail!
Note
For the approval of the boiler standpipe and the mounting flange the relevant regula-
tions must be observed.
See pages 14 and 15 for typical examples of installation.

13
Repositioning the terminal box
Dismounting the terminal box
1. Undo cover screws Hand remove cover I, Fig. 3.
2. Pull electrode cables off the terminal lugs.
3. Unscrew and remove fixing nut Jwith open-end spanner 19 mm A. F. Pull electrodes cables
through the fixing nut J.
4. Remove terminal box and pull electrode lines through the hole of the fixing screw.
5. Remove gasket Abetween electrode and terminal box.
Mounting the terminal box
1. Depending on the desired position of installation, unscrew the corresponding sealing plug Oand
screw it into the bore in which the electrode rod was previously screwed, Fig. 4.
2. Put gasket Aonto the electrode rod. Use only undamaged gaskets.
3. Pull electrode cables through the now free bore in the terminal box and put the terminal box onto
the electrode rod, making sure that the gasket fits correctly between the electrode rod and the
terminal box.
4. Pull electrode cables through fixing nut J. Use a 19 mm A. F. spanner to attach the fixing nut Jto
the fixing screw and tighten with a torque of 25 Nm.
5. Connect electrode cables to terminal lugs according to the wiring diagram, Fig. 8.
6. Replace cover Iand fasten cover screws H.
Installation – continued –
Tools
Open-end spanner 19 mm A. F.
Open-end spanner 41 mm A. F.
Screwdriver for cross-recess head screws, size 1 and 2
Mounting conductivity switch LRGS 15-1
1. Check sealing surfaces of boiler standpipe or flange (see Fig. 2) and, if necessary, re-finish them as
specified in the drawing.
2. Put the supplied joint ring Donto the seating surface of the conductivity switch.
3. Apply a light smear of silicone grease to the thread of the conductivity switch.
4. Screw the conductivity switch into the boiler standpipe or flange and tighten with an open-end
spanner 41 mm A. F. The torque when cold is 160 Nm.

14
A
Examples of Installation
Fig. 5
LRGS 15-1 used as conductivity electrode
LRGS 15-1 used for continuous blowdown control
Fig. 6
LRGS 15-1
LRGS 15-1
P D
P Q R T D
~ 250
400 406
¾" to ISO 228-1
R 50
~ 250
600 406
¾" to ISO 228-1
R 50
197
DN
[mm]
A
[mm]
15 182
20 184
25 184
40 189
NW
LW
NB
NB

15
M
Examples of Installation – continued –
DJoint ring 27 x 32, form D, DIN 7603, 2.4068, bright annealed
PBoiler drum
QShut-off valve GAV
RContinuous blowdown valve BAE
SMeasuring pot
TT-type connector
Key
Fig. 7
LRGS 15-1 used for continuous blowdown control
LRGS 15-1
R
Q
¾" to ISO 228-1
DN 15-40
Outlet
Inlet
DN 15-40 S D

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Electrical Connection
Before establishing the electrical connection align the terminal box such that all indicators and
adjustors are easily accessible and the cable outlets point into the desired direction.
1. Undo cover screws Hand remove cover I(Fig. 3).
2. Unscrew fixing nut Jwith an open-end spanner 19 mm A. F. and rotate the terminal box into the
desired direction.
3. Tighten fixing nut Jwith a torque of 25 Nm.
4. Replace cover Iand tighten cover nuts J.
Aligning the terminal box
Multi-core flexible control cable (CSA of conductor: 0.75 – 1.5 mm2) can be used for wiring.
1. Undo cover screws Hand remove cover I, Fig. 3, 4.
2. Detach terminal strips Mfrom electronic insert.
3. Strip off approx. 40 mm of cable insulation coating and remove approx. 5 mm of conductor end
insulation.
4. Undo cable glands N. Pull mains cable through the cable gland on the right hand side and the
control lines through the other cable glands.
5. Connect the mains and control lines to the terminal strips Maccording to the wiring diagram
(inside of cover).
6. Attach the terminal strips Mto the electronic insert.
7. For connecting an external resistance thermometer use a screened two-core cable,
e. g. Ölflex 110 CH, manufactured by LAPP, 2 x 0.5 mm2. Max. cable length between resistance
thermometer and conductivity switch: 25 m.
8. When connecting an external resistance thermometer strip off approx. 20 cm of cable insulation
and remove approx. 5 mm of conductor end insulation.
9. If an additional cable entry is required, replace one of the sealing plugs with a cable gland
M 16 x 1.5
10. Terminate all wire ends with crimp connectors 2.8 x 0.8 and connect them to the terminal lugs as
indicated in the wiring diagram. Connect the screen to the thermometer.
11. Replace cover Iand tighten cover screws H.
Connecting conductivity transmitter LRGS 15-1

17
Electrical Connection – continued –
Attention
Note that the following basic insulated lines must not be installed in extra-low voltage
areas: mains and control lines.
To prevent the welding together of contacts provide an external slow-blow fuse T 2 A
for the output contacts.
Connected contactors must be provided with interference suppressors
(RC combinations) as specified by the manufacturer.
Provide an external slow-blow fuse 63 A (at 230 V) or 125 mA (at 115 V) for the
coductivity switch.
For disconnecting the conductivity switch install an easily accessible disconnecting
switch in the close proximity of the equipment (EN 61010-1).
Mark the disconnecting switch as isolating device for the conductivity switch.
Tools
Screwdriver for cross-recess head screws, size 1 and 2
Screwdriver for slotted screws, size 2.5, completely insulated to VDE 0680
Open-end spanner 19 mm A. F.

18
Electrical Connection – continued –
Wiring diagram for conductivity switch LRGS 15-1
1
13L22 22L13
LRGS 15-1
1NN
P5
P8
P6
P11
P4
P9
P7
P10
P1P2P3
13 2910 5411
After the burner is switched off (stand-by operation), L2 must remain live until the actuator has closed
the continuous blowdown valve. L1 and L2 must be connected to an outer conductor of the same
phase.
If no resistance thermometer is connected, the terminal lugs P 6, 7, 10 and 11 remain unassigned.
Fig. 8 Actuator EF 1 / EF 06
Temp.
feeler
Pt 100
μS
ppm
Alarm
Max
ϑF1 F2
S1 Disconnector
F1 Fuse for output contact
F2 Fuse for conductivity switch
S1
Operation
OpenClosed

19
Commissioning
Function of the keys
Key 1 (P): For entering parameter setting mode
Key 2: Decrease value, scroll up
Key 3: Increase value, scroll down
Key 4 (E): Leave parameter setting mode, return to input mode and save settings
7 Segment display
Indicating actual value or setpoint, temperature, error code
LEDs 1 – 5
LED 1: The 7-segment display shows the setpoint
LED 2: The 7-segment display shows the actual value
LED 3: MAX limit reached
LED 4: Continuous blowdown valve opens
LED 5 Continuous blowdown valve in operating position
Keys and indicators
1. Make sure that the conductivity switch is connected in accordance with the wiring diagram.
2. Verify that the available supply voltage corresponds to the voltage that is stated on the name plate.
Checking electrical connection
Apply mains voltage. First the type designation and the software version are briefly indicated, then the
actual value is shown on the 7-segment display.
Applying mains voltage
1
2
3
4
5

20
Commissioning – continued –
Factory settings
When the conductivity switch LRGS 15-1 I started, it has the following default settings:
Setpoint: 5000 µS/cm
MAX limit: 8000 µS/cm
Correction of measured value (CF): 0.2
PT 100: OFF
Temperature coefficient: 2.1 %/C
Unit: µS/cm
Setting parameters
To enter the parameter setting mode press button P.
Setting parameter
Key Parameter Display Key Adjustment range Key Display
→P
←P1 Setpoint 1._SP → E ← P
100-9999 µS/cm
press key or 
to change →E
SAVE
return to
1 Setpoint

2 MAX limit 2._AL → E
← P
100-9999 µS/cm
press key or 
to change →E
SAVE
return to
2 MAX limit


3 Correction of
measured value 3._CF → E
← P
0.050-5.000
press key or 
to change →E
SAVE
return to
3 Correction
of measured value

4 PT 100 4._Pt → E
← P
ON / OFF
press key or 
to change →E
SAVE
return to
4 PT 100

4.1 TK 4.1.tC → E
← P
1.6 to 3.0 %/°C
press key or 
to change →E
SAVE
return to
4.1 TK

5 Unit 5._dI → E
← P
µS/cm / ppm
press key or 
to change →E
SAVE
return to
5 Unit
To return to normal operation press again button P.