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
4
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
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
10
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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