GESTRA LRS 1-7 Manual

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LRS 1-7
Installation & Operating Instructions
818872-02
Conductivity Switch
LRS 1-7
GESTRA Steam Systems
EN
English

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Contents
Usage for the intended purpose ..............................................................................................................4
Safety Notes ...........................................................................................................................................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
Description .............................................................................................................................................5
Function .................................................................................................................................................5
LRS 1-7..................................................................................................................................................9
Key.......................................................................................................................................................10
Dimensions / Functional Elements
Electrical Connection
Technical Data
LRS 1-7.............................................................................................................................................. 6, 7
Name plate / Marking .............................................................................................................................8
Connecting conductivity electrode LRG 16-9.........................................................................................11
Attention...............................................................................................................................................11
Connecting conductivity electrode ERL 16, LRG 16-4............................................................................11
Connecting conductivity switch LRS 1-7 ...............................................................................................12
Connecting power output......................................................................................................................12
Attention...............................................................................................................................................12
Tools.....................................................................................................................................................12
Wiring diagram for conductivity switch LRS 1-7 (continuous blowdown control)....................................13
Wiring diagram for conductivity switch LRS 1-7 (water monitoring).......................................................14
Conductivity switch LRS 1-7 .................................................................................................................11
Installation

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Contents - continued -
Page
LRS 1-7................................................................................................................................................19
Fault finding list for troubleshooting................................................................................................ 20, 21
Malfunctions
LRS 1-7................................................................................................................................................18
Note .....................................................................................................................................................18
Operation
Danger .................................................................................................................................................22
Exchanging the conductivity switch ......................................................................................................22
Disposal................................................................................................................................................22
Decommissioning
Commissioning
Keys and indicators ..............................................................................................................................15
Checking electrical connection .............................................................................................................15
Applying mains voltage.........................................................................................................................15
Factory setting......................................................................................................................................16
Setting parameters ......................................................................................................................... 16, 17

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Important Notes
Usage for the intended purpose
The conductivity switch LRS 1-7 in conjunction with the conductivity electrode LRG 16-9,
ERL 16, LRG 16-4 is designed for measuring and monitoring the electrical conductivity in conductive
liquids.
Safety note
Danger
The terminal strips of the conductivity switch LRS 1-7 are live during operation.
This presents the risk of severe cases of electric shock!
Always cut off power supply to the equipment before mounting, removing or connecting
the terminal strips!
The equipment must only be installed 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.
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.
ATEX (Atmosphere 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.

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Function
The conductivity switch LRS 1-7 in conjunction with the conductivity electrode LRG 16-9, ERL 16,
LRG 16-4 measures and monitors the electrical conductivity in conductive liquids. The conductivity
switch is designed for the connection of a conductivity electrode with a cell constant of 0.5 cm-1.
The integrated resistance thermometer enables the conductivity electrode LRG 16-9 to measure the
fluid temperature.
The electrical conductivity changes as the water temperature changes. To obtain readings that can be
used for comparison the measurement must be based on a standard reference temperature of 25 °C.
The water temperature is measured and the conductivity reading is automatically compensated as a
function of the adjusted temperature coefficient Tk(%/°C). If the temperature changes the measured
value will be linearly based on 25 °C over the whole measuring range thanks to the temperature
compensation.
An adjustable contact triggers a signal when the MAX limit is reached.
A two-point controller is integrated in the conductivity switch so that the equipment can also be used
in steam boiler installations. The two-point controller controls a continuous blowdown valve and auto-
matically closes it when the boiler is shut down.
In addition the valve can be opened and closed at certain intervalvs (purging pulses). This prevents the
continuous blowdown valve from getting stuck.
A current signal of 4 - 20 mA is available for external processing. The current signal is proportional to
the conductivity reading (as a function of the adjusted measuring range).
A short circuit or wire breakage in the conductivity electrode will trigger an error message in the
conductivity switch.
The electrical conductivity is measured in μS/cm. In some countries parts per million (ppm) is used
instead. Conversion 1 μS/cm = 0.5 ppm. The conductivity switch can be adjusted accordingly.
Explanatory Notes
Scope of supply
LRS 1-7
1 Conductivity switch LRS 1-7
1 Adhesive plate ppm
1 Installation manual
Description
The conductivity switch LRS 1-7 in conjunction with the conductivity electrode LRG 16-9 constitutes a
conductivity monitoring and control system. The electrical conductvity of
nCondensate,
nBoiler feedwater,
nCooling and cleaning water,
nBoiler water
is monitored. In steam boiler plants the conductivity monitoring & control system is used as limit
switch and continuous blowdown controller.

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LRS 1-7
Type approval
TÜV.WÜL.xx-014
Supply voltage
230 V, +10 / –15 %, 50-60 Hz
115 V, +10 / –15 %, 50-60 Hz (option)
Input
1 Input for conductivity electrode LRG 16-9 (with cell constant 0.5 cm-1)
Output
2 volt-free relay contacts,
max. contact rating for switching voltages 115 V AC and 230 V AC: resistive / inductive 4 A.
Provide contactor with interference suppressor (RC combination).
Contact material: AgNi 0,15.
1 Current output 4-20 mA as actual value output, max. load 500 Ω
Measuring range
0.5 up to 10000 μS/cm at 25 °C or 0.25 up to 5000 ppm at 25 °C
Setpoint W
adjustable between 0.5 and 9999 μS/cm or 0.25 up to 5000 ppm
Limit MAX
adjustable between 0.5 and 9999 μS/cm or 0.25 up to 5000 ppm
Correction factor
adjustable between 0.05 and 5000, adjustable in increments of 0.001
Temperature coeffizient Tk
0.0 – 3.0 % per °C, adjustable in increments of 0.1
Actual value output (option)
0.5 mA in the event of failure (E.01-E.04, at the end of the start phase)
4 mA corresponds to 0.5 μS/cm
20 mA corresponds to 10, 200, 500, 1000, 6000, 9999 μS/cm, final values adjustable
Purging interval (continuous blowdown valve is forced to open)
adjustable between 1 h and 24 h in increments of 1 h.
Duration of purging
adjustable between 1 min. and 6 min. in increments of 1 min.
Switching hysteresis
Controller output: – 10 % of the adjusted setpoint W,
Limit MAX: – 3 % of the adjusted MAX limit
Cycle of measurement
1 sec.
Time constant T
Temperature: 20 sec.
Technical Data

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Conductivity: 28 sec.
Indicators and adjustors
1 four-digit, seven-segment indicator, red, for indicating the actual value (X) / setpoint (W) and for
status and error messages
2 amber LEDs for indicating actual value / setpoint
1 red LED for indicating MAX limit
2 green LEDs for indicating valve OPEN / CLOSED
4 pushbuttons for value and parameter settings
Power consumption
6 VA
Fuse
external 63 mA, slow blow, at 230 V,
external 125 mA, slow blow, at 115 V
Protection
IP 65 to DIN EN 60529
Protection class
2 (totally insulated)
Ambient temperature
Max. 70 °C
Housing
Housing material: Polycarbonate
Cable entry / Wiring
Cable gland with integral cable clamp, 3 x M 16 x 1.5
1 four-pole screw-type terminal strip for power supply,
1 three-pole screw-type terminal strip for connecting the continuous blowdown valve,
1 three-pole screw-type terminal strip for MAX limit,
1 two-pole screw-type terminal strip for current output 4-20 mA,
Terminal strips detachable, conductor size: 1.5 mm2
1 Sensor jack M12, with 5 poles, A coded, for connecting the conductivity electrode
Cable length
max. 30 m, with conductivities from 0.5 to 10 μS/cm: max. 10 m
Weight
Approx. 0.8 kg
Technical Data - continued -
LRS 1-7 - continued -

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Technical Data - continued -
Name plate / Marking
Equipment designation
Fig. 1
Power rating
Protection
Electrical specification
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 ~ T 2,0 A
6VA
LRS 1-7
0,5-10000μS/cm
0,25-5000ppm
GESTRA AG
Münchener Str. 77
D-28215 Bremen
Tamb = 70°C (158 °F)
IP65
50/60 Hz
VS.-Nr.: Mat.-Nr.:
230VAC
Leitfähigkeitsschalter
Conductivity Limit Switches
Commutateurs de valeurs
limites de conductibilité
TÜV . WÜL . xx - 014

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Dimensions / Functional Elements
Fig. 2
LRS 1-7
7
2
1
6
Fig. 3
c
b
0
9 8
5
3
4
a
180
129
60
d

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Dimensions / Functional Elements - continued -
1LED 1: The actual value is shown on the seven-segment display
2LED 2: The setpoint is shown on the seven-segment display
3LED 3: MAX limit reached
4LED 4: The continuous blowdown valve opens
5LED 5: Continuous blowdown valve in operating position
6Seven-segment display, indication of actual value or setpoint, temperature, error code
7Pushbuttons
8Cover screws (cross recess head screws M4)
9Housing cover
0M 12 sensor jack, 5 poles, A coded
aTerminal strips
bCable glands 3 x M 16 x 1.5
cSealing plug
dFixing hole ∅ 4.5 mm
Key