Spirax Sarco LCS3051 User manual

IM-P693-07 EMM Issue 2 1
LCS3051 High Water Level Switch
850147-01
LCS3051
High Water Level Switch
Installation and Maintenance Instructions
IM-P693-07
EMM Issue 2
1. Safety information
2. General product information
3. Mechanical installation
4. Electrical installation
5. Commissioning
6. Fault finding
7. Technical information
8. Technical assistance
© Copyright 2020
Printed in Germany

IM-P693-07 EMM Issue 2
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LCS3051 High Water Level Switch

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LCS3051 High Water Level Switch
1. Safety information
High water level alarms are safety devices and must only be installed, wired and commissioned
by qualified and competent staff. Incorrect installation, wiring or commissioning can impact the
safe operation of the device.
Retrofitting and maintenance work must only be performed by qualified staff who – through adequate
training – have achieved a recognised level of competence.
Danger
The terminal strips of the LCS3051 are live during operation.
This presents the danger of electric shock!
Always cut off power supply to the equipment before mounting, removing or connecting
the terminal strips!
Important
The name plate specifies the technical features of the equipment. Note that any piece
of equipment without its specific name plate must neither be commissioned nor
operated.
1.1 Directives and Standards
Pressure Equipment Directive (PED) 2014/68/EU
The level switch LCS3051 in conjunction with level probe LP41 is EU type approved according to
EN 12952/ EN 12953. These Directives state, among other things, the requirements made on limiting
systems and equipment for steam boiler plants and (pressurised) hot-water installations.
Functional Safety according to IEC 61508
The level switch LCS3051 is certified according to IEC 61508 only if used in combination with level
probe LP41. This standard describes the functional safety of safety-related electrical/electronic/
programmable electronic systems.
The equipment combination LP41 + LCS3051 corresponds to a type B subsystem with Safety
Integrity Level (SIL) 2.
VdTÜV Bulletin “Wasserstand 100” (Water Level 100)
The level switch LCS3051 in conjunction with the level probe LP41 is type approved according to
the VdTÜV Bulletin "Water Level 100".
The VdTÜV Bulletin “Wasserstand (Water Level) 100” specifies the requirements made on water
level control and limiting equipment for boilers.
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility)
The level switch LCS3051 meets the requirements of the Low Voltage Directive 2014/35/EU and the
EMC Directive 2014/30/EU.
ATEX (Atmosphère Explosible)
According to the European Directive 2014/34/EU the level switch LCS3051 must not be used in
potentially explosive areas.

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LCS3051 High Water Level Switch
Note
The level probe LP41 is a simple item of electrical equipment as specied in EN 60079-
11 section 5.7. According to the European Directive 2014/34/EU the equipment must be
equipped with approved Zener barriers if used in potentially explosive areas. Applicable
in Ex zones 1, 2 (1999/92/EC).
The equipment does not bear an Ex marking.
Note: The requirements of the IEC 61508 are not met if the LP41 + Zener barriers +
LCS3051 are interconnected!
1.2 Functional Safety according to IEC 61508
Safety characteristics of the subsystem LP41/LCS3051
The level switch LCS3051 is certified acc. to IEC 61508 only if used in combination with level probe
LP41.
The equipment combination LP41/LCS3051 corresponds to a type B subsystem with Safety Integrity
Level (SIL) 2. Type B means that the behaviour under fault conditions of the used components
cannot be completely determined. The functional safety of the equipment combination refers to
the detection and evaluation of the water level and, as a consequence, the contact position of the
output relays.
The design of the equipment combination LP41/LCS3051 corresponds to the architecture 1oo2.
This architecture consists of two channels that detect and diagnose faults in each other. If a fault
is detected, the equipment combination LP41/LCS3051 will go to the safe state, which means that
the contacts of both output relays will open the safety circuit.
Table 1
Safety characteristics SIL Architecture Lifetime (a) Proof Test
Interval (a)
General 21oo2 20 20
SFF PFDav PFHav λ DU
Level switch LCS3051 in
conjunction with one level
probe LP41
>90% <5 x 10-3 <5 x 10-7 <5 x 10-7/h

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LCS3051 High Water Level Switch
1.3 Terms and abbreviations
Table 2
Terms/Abbreviations Description
Safety Integrity Level/SIL Classification of the Safety Integrity Level acc. to IEC 61508
Lifetime (a) Functional safety: Lifetime in years
Safe Failure Fraction/SFF Percentage of failures without the potential to put the safety-
related system into a dangerous state
Probability Failure per Demand
(Low Demand)/PFDav
Average probability of failure on demand for low demand
mode (once a year)
Probability Failure per Hour/PFHav Probability of failure per hour
λDU Failure rate for all dangerous undetected failures (per hour)
of a channel of a subsystem
Determination of the Safety Integrity Level (SIL) for safety-related systems
Level probe, level switch and actuators (auxiliary contactors in safety circuit) are subsystems and
together constitute a safety-related system that executes a safety function.
The specification of the safety-related characteristics Table 1 refers to the level probe and the level
switch including the output contacts. The actuator (e. g. an auxiliary contactor in the safety circuit)
is installation specific and, according to IEC 61508, must be considered separately for the whole
safety-related system.
Table 3 shows the dependence of the Safety Integrity Level (SIL) on the average probability of
failure on demand of a safety function for the whole safety-related system (PFDsys). The “Low
demand mode” is here considered for a water level limiter, which means that the frequency of
demands for operation of the safety-related system is no greater than one per year.
Table 3
Low demand mode PFDsys Safety Integrity Level (SIL)
≥ 10 -5 ... < 10 -4 4
≥ 10 -4 ... < 10 -3 3
≥ 10 -3 ... < 10 -2 2
≥ 10 -2 ... < 10 -1 1
Table 4 indicates the attainable Safety Integrity Level (SIL) as a function of the Safe Failure Fraction
(SFF) and the Hardware Fault Tolerance (HFT) for safety-related systems.
Table 4
Hardware Fault Tolerance (HFT) for type B Safe Failure Fraction (SFF)
012
SIL 1 SIL 2 < 60 %
SIL 1 SIL 2 SIL 3 60 % - < 90 %
SIL 2 SIL 3 SIL 4 90 % - < 99 %
SIL 3 SIL 4 SIL 4 ≥ 99 %

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LCS3051 High Water Level Switch
2. General product information
2.1 Intended use
The level switch LCS3051 is used in conjunction with level probe LP41 as high level alarm in steam boilers
and (pressurised) hot-water plants.
A high level alarm prevents the water level from exceeding the preset max. water level (HW) and for this
purpose switches off e. g. the feedwater supply.
2.2 Function
The level switch LCS3051 is designed for connecting one level probe. See section Schematic representations
of arrangements on page 10.
When the water level exceeds the MAX limit, the level probe enters the liquid and an alarm is triggered in the
level switch. This switchpoint is determined by the length of the probe rod (level probe LP41).
After the de-energizing delay has elapsed, both output contacts of the level switch will open the safety circuit,
e. g. for the feedwater supply. If the deactivation of the feedwater supply is interlocked in the external safety
circuit, the lockout can only de deactivated when the level probe is exposed again.
An alarm will also be raised if a malfunction occurs in the level probe and/or the electrical connection.
An automatic self-testing routine monitors the safet y functions of the level switch. In the event of a malfunction
the safety circuit opens instantaneously and switches off e. g. the feedwater supply.
Alarm and malfunction messages are indicated by LEDs, and the signal output is instantaneously energized.
An alarm can be simulated by pressing the test button.
Fig. 1
Note
A high level alarm prevents the water level from exceeding the preset max. liquid level
( H W ) . F o r t h i s p u r p o s e i t c a n , f o r i n s t a n c e , i n t e r r u p t t h e f e e d w a t e r s u p p l y . I f t h e i n t e r r up t i o n
of the feedwater supply endangers the heating surfaces in the feedwater preheater
(economizer), the heating must be switched o󰀨, too.

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LCS3051 High Water Level Switch
3.1 Dimensions (approximate) in mm
3. Mechanical installation
Item
1Upper terminal strip
2Lower terminal strip
3Fixing screws (cross recess head screws M3)
4Enclosure
5Supporting rail type TH 35, EN 60715
Fig. 2
The code switches are accessible after removing the lower terminal strip. The terminal strips can be unplugged
after undoing the right and the left fixing screws.
5
100
73
118
32
1
4

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LCS3051 High Water Level Switch
Alarm Signal
24 VDC
100 mA
CEP
Tamb =55°C (131°F)T
7 W IP 40 (IP20)
0525
250V
T 2,0A
TÜV.SHWS.XX-XXX
20 21
3sec.
10 µS/cm
2
LP 41
32 1
134516 17 23 24 26 27
LCS3051
MAX M 0,5A
4-393314-02
LCS3051
High Water Level Limiter
Level Switch
Niveauschalter
Commutateur de niveau
Functional safety
IEC 61508
SIL 2
MADE IN GERMANY
24 V=
24 V
±20%
See installation
instructions
Betriebsanleitung
beachten
Voir instructions de
montage
AL
+
_
+
_
3.2 Installation in control cabinet
The level switch LCS3051 is clipped onto the support rail 7 type TH 35, EN 60715 in the control cabinet.
Name-plates
1Safety note
2Wiring diagram
3Manufacturer
4Type designation
5Supply voltage/Protection
6Ambient temperature/sensitivity
7Safety circuit
8Wire link,provided on site
9Fuse, provided on site
10 Type-approval no.
11 Disposal note
Fig. 3
1
2
3
6
5
8
7
4
9
10
11
TÜV.SHWS.XX-XXX
Serial number

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LCS3051 High Water Level Switch
2716
12345678
17 18 19 20 21 22 23 24
9
25
10
26
11 12
28
13
29
14
30
15
4. Electrical installation
Item
1Power supply
2Signal output 1 for external alarm 24 Vdc, 100mA (semiconductor output)
3Safety circuit, input and output
4Wire link, fitted on site, when used as high water level alarm acc. to EN 12952/EN 12953
5CEP Central earthing point in control cabinet
6Level probe LP41.
Fig. 4
4.1 Wiring diagram
1 2
3
4
3
6LP41
5

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LCS3051 High Water Level Switch
Item
1Level probe LP41
2Level switch LCS3051
3Safety circuit
Steam boiler plants according to EN 12952-07/EN 12953-06, 72 h operation
Fig. 5 Combination consisting of 1 level probe LP41 and 1 level switch LCS3051 as high water level alarm.
Functional safety IEC 61508, SIL 2.
Further applications in accordance with national sets of regulations
Fig. 6 Combination consisting of 1 level probe LP41 and 1 level switch LCS3051 as high water level alarm.
The level switch opens two separate safety circuits. Functional safety IEC 61508, SIL 2.
4.3 Connection of supply voltage
Provide the level switch LCS3051 with an external semi-delay fuse 0.5 A.
Danger
For the supply of the level switch LCS3051 with 24 Vdc use a safety extra-low voltage
(SELV) power supply unit that must be electrically isolated from dangerous contact
voltages and must meet at least the requirements on double or reinforced isolation
acc. to EN 50178, EN 61010-1, EN 60730-1, EN 60950-1 or EN 62368-1 (safe electrical
isolation).
4.4 Connection of level probe
To connect the level probe please use screened multi-core control cable, min. conductor size 0.5 mm2, e.g.
LiYCY 4 x 0.5 mm2, max. length 100 m.
Wire terminal strip in accordance with the wiring diagram. Fig. 4. Connect screens to terminal 5 and to the
central earthing point (CEP) in the control cabinet.
4.2 Schematic representations of arrangements
Fig. 5 Fig. 6
12
3
12
3

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LCS3051 High Water Level Switch
4.5 Connection for signal output
A signal output for the connection of external signalling equipment is allocated to the monitoring channel
in the level switch, max. load 100 mA. For connecting the level switch with the signal output use a control
cable, e.g. 2 x 0.5 mm2. In the event of an alarm or error message the signal output (terminals 20, 21) closes
instantaneously.
4.6 Connection of safety circuit
Connect the safety circuit for the feedwater supply/heating to terminals 23, 24 and 26, 27. When used as
high water level alarm to EN 12952/EN 12953 connect the output contacts of both monitoring channels by
fitting a wire link between the terminals 24 and 26.
Fuse the output contacts with a 2 A or 1 A slow-blow fuse.
Note
-A high level alarm prevents the water level from exceeding the preset max. liquid level
(HW). For this purpose it can, for instanc e, interrupt the feedwater supply. If the interruption
of the feedwater supply endangers the heating surfaces in the feedwater preheater
(economizer), the heating must be switched off, too.
-In the event of an alarm the level switch LCS3051 does not interlock automatically.
If a lockout function is required by the installation it must be provided in the follow-up
circuitry (safety circuit). The circuitry must meet the requirements of the EN 50156.
Important
-Fuse the level switch LCS3051 with an external semi-delay fuse 0.5 A.
-Connect screens to terminal 5 and to the central earthing point (CEP) in the
control cabinet.
-To protect the switching contacts fuse the safety circuit with a slow-blow fuse
2 A or 1 A.
-When switching off inductive loads, voltage spikes are produced that may impair
the operation of control and measuring systems. Connected inductive loads
must be provided with suppressors such as RC combinations as specified by
the manufacturer.
-When used as high water level alarm according to EN 12952/EN 12953 connect
terminals 24 and 26 by fitting a wire link.
-Install connecting lines to level probes separated from power cables.
-Do not use unused terminals as support point terminals.
4.7 Tools
Screwdriver for slotted screws, size 3.5 x 100 mm, completely insulated according to VDE 0680-1.

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LCS3051 High Water Level Switch
5.1 Factory setting
-De-energizing delay: 3 sec (factory set).
Danger
The terminal strips of the LCS3051 are live during operation.
This presents the danger of electric shock!
Always cut off power supply to the equipment before mounting, removing or
connecting the terminal strips!
5. Commissioning
5.2 Checking switchpoint and function
Level probe 1
Test and diagnosis button
LED alarm 1 / operating mode
Diagnosis LED
Fig. 7
Start
Activity Indication Function
Apply supply voltage.
All LEDs are illuminated.
System is being started and tested, this
takes approx. 10 sec.
Output contacts are open.
Signal output 1 closed.
All LEDs are illuminated for more
than 10 sec.
System malfunction. Possible causes: Faulty
power supply, level switch defective.
Lower water level in boiler until the
level falls below the switchpoint
high water level (HW). Level probe
is exposed.
Green LED
for level probe 1 is illuminated
Output contacts are closed.
Signal output 1 is open.
Checking switchpoint and function
Raise level in boiler until the
switchpoint “high water level (HW)”
is exceeded. Level probe enters the
water.
Red LED for level probe 1 is
flashing
De-energizing delay is running.
Signal output 1 is closed instantaneously.
Red LED for level probe 1 is
illuminated
Delay time has elapsed, output contacts open.
Signal output 1 is closed.

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LCS3051 High Water Level Switch
Possible installation faults
Status and indication Fault Remedy
Sightglass indicates high water
level (HW) exceeded,red LED for
level probe 1 is not illuminated.
Safety circuit closed.
The probe rod is too short. Replace probe rod and cut new rod to the
length dictated by the switchpoint HW.
The earth connection to the
vessel is interrupted.
Clean probe threads and ensure excessive
PTFE tape has not been applied.
Electrical conductivity of the
boiler water too low. Correct water conductivity.
If installed inside the boiler:
Upper vent hole in protection
tube does not exist or is
obstructed.
Check installation of level probe. Make sure
that the level in the protection tube cor-
responds to the actual water level.
Water level sufficient. Red LED for
level probe 1 is illuminated. Safety
circuit is open.
Probe rod is too long. Cut probe rod to the length dictated by the
switchpoint HW.
Upper vent hole flooded.
Check installation of level probe. Make
sure that the level in the protection tube
corresponds to the actual water level.

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LCS3051 High Water Level Switch
5.3 Operation, Alarm and Test
Fig. 8
Operation
Activity Indication Function
Level probe exposed Green LED for level probe 1 is
illuminated
Output contacts are closed. Signal
output 1 is open.
Alarm
Level probe submerged, high water
level (HW) exceeded.
Red LED for level probe 1 is flashing
De-energizing delay is running.
Signal output 1 is closed
instantaneously.
Red LED for level probe 1 is
illuminated
Delay time has elapsed, output
contacts open. Signal output 1 is
closed.
Test channel 1
During operation:
Press and hold down key 1 until the
end of the test, level switch must
function as if there were an alarm.
Red LED for level probe 1 is flashing
Alarm simulated in channel 1.
De-energizing delay is running.
Signal output 1 is closed
instantaneously.
Red LED for level probe 1 is
illuminated
Delay time has elapsed, output
contacts open. Signal output 1 is
closed. Test finished.
Replace level switch if the test was not finished successfully.
Level probe 1
Test and diagnosis button
LED alarm 1 /operating mode
Diagnosis LED

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LCS3051 High Water Level Switch
6. Fault finding
6.1 Display, diagnosis and troubleshooting
Important
Before carrying out the fault diagnosis please check:
Supply voltage
Is the level switch supplied with the voltage specified on the name plate?
Wiring
Is the wiring in accordance with the wiring diagram and the relevant schematic
representation of arrangement?
Malfunction in level probe
Status Fault Remedy
Water level sufficient. Red LED for
level probe 1 is illuminated. Safety
circuit is open.
The insulation of the level probe is dirty
or faulty.
Clean or, if necessary, replace level
probe.
Further fault indications
Status Diagnosis Function Next activity
Faulty evaluation of level
probe 1, channel 1
Diagnosis LED 1 and
LED alarm 1 illuminated.
Output contacts are opened
instantaneously.
Signal output 1 closes
instantaneously.
next:
Press key AL.
Malfunction in level switch
detected.
Diagnosis LED 3 and
LED alarm 1 or 2 illuminated.
Output contacts are opened
instantaneously.
Signal output 1 closes
instantaneously.
next:
Press key AL.

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LCS3051 High Water Level Switch
Diagnosis
Display 1 and activity Display 2 Fault Remedy
LED alarm 1 and diagnosis
LED 1 illuminated.
Press and hold down key AL.
Diagnosis LED 1 flashing.
Malfunction in level probe 1,
malfunction in level switch,
faulty wiring,
faulty measuring voltage. Check wiring,
replace level switch.
Diagnosis LED 2 flashing.
Malfunction in level probe 1,
malfunction in level switch,
faulty wiring.
Diagnosis LED 3 flashing.
Interference voltage causing
malfunction, boiler earth
without PE
Provide screen and earthing,
connect boiler with PE.
LED alarm 1 and Diagnosis
LED 3 illuminated.
Press and hold down key AL.
Diagnosis LED 1 flashing. Malfunction in processor,
stand-by fault.
Replace level switch.
Diagnosis LED 2 flashing. Internal voltage fault.
Diagnosis LED 3 flashing. Malfunction in relay.
Once the fault is eliminated, the level switch returns to normal operation.
After elimination of the fault switch off the supply voltage and switch it on again after approx. 5 sec.
If faults occur that are not listed above or cannot be corrected, please
contact our service centre or authorized agency in your country.

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LCS3051 High Water Level Switch
6.2 Action against high frequency interference
Should sporadic failures occur in installations susceptible to faults (e. g. malfunctions due to out-of-phase
switching operations) we recommend the following actions in order to suppress interferences:
-Provide inductive loads with RC combinations according to manufacturer's specification to ensure
interference suppression.
-Make sure that connecting cables leading to the level probes are segregated and run separately from
power cables
-Increase the distance to sources of interference.
-Check the connection of the screen to the central earthing point (CEP) in the control cabinet.
-HF interference suppression by means of hinged-shell ferrite rings.
6.3 Interlock and interlock deactivation
In the event of an alarm the level switch LCS3051 does not interlock automatically.
If a lockout function is required by the installation it must be provided in the follow-up circuitr y (safet y circuit).
The circuitry must meet the requirements of the EN 50156.
6.4 Checking the switchpoints
To check the switchpoint “High water level (HW) exceeded” you have to fill the boiler until the max. water level
is reached. As soon as the high level is reached the level switch must trigger an alarm and open the safety
circuit after the de-energizing delay has elapsed The deactivation of the heating is interlocked in the safety
circuit and the lockout can only be reset when the level probe is exposed again. Always check the switchpoint
when commissioning the equipment, after replacing the level probe and at regular intervals, e. g. every year.
6.5 Decommissioning/replacing level switch
-Switch off supply voltage and cut off power supply to the equipment.
-Unscrew the right and left fixing screws 3 and remove the upper and lower terminal strips 1, 2, Fig. 2
-Undo the fixing slide in order to snap out the level switch and take it off the supporting rail.
6.6 Disposal
Remove the level switch and separate the waste materials in accordance with the material specification.
Electronic component parts such as the circuit board must be disposed of separately!
For the disposal of the level switch observe the pertinent legal regulations concerning waste disposal.

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LCS3051 High Water Level Switch
7. Technical information
Supply voltage 24 Vdc +/– 20%
External fuse 0.5 A (semi-delay)
Power consumption 7 W
Response sensitivity
(Electrical conductivity
of water at 25 °C)
> 10 ... < 10000 μS/cm
Electrical
connection of level
probe
1 input for level probe LP41, 4-poles with screen
Safety circuit
2 volt-free make contacts, 6 A 250 Vac/30 Vdc cos vvv = 1.
Delay of response: 3 seconds.
Provide inductive loads with RC combinations according to manufacturer's specification to ensure
interference suppression.
Signal output 1 volt-free output for instantaneous external signalling, 24 Vdc, max. 100 mA (semiconductor
output)
Indicators and
adjustors
1 button for test and diagnosis
1 red/green LED for indicating the operating mode and alarm
3 red LEDs for diagnosis
Housing
Housing material: base: polycarbonate, black; front: polycarbonate, grey.
Cross section of connection: 1 x 4.0 mm2solid per wire or
1 x 2.5 mm2per stranded wire with sleeve to DIN 46228 or
2 x 1.4 mm2per stranded wire with sleeve to DIN 46228; terminal strips can be detached
Fixing of housing: Mounting clip on supporting rail TH 35, EN 60715
Electrical safety Degree of contamination: 2, overvoltage category III to EN 61010-01
Protection
Housing: IP 40 to EN 60529
Terminal strip: IP 20 to EN 60529
Weight approx. 0.5 kg
Further conditions:
Ambient temperature
when system is switched on: 0 ... 55 °C
during operation: –10 ... 55 °C
Transport
temperature
–20 ... +80 °C (< 100 hours), defrosting time of the de-energized equipment before it can be put
into operation: 24 hours

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LCS3051 High Water Level Switch
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
Approvals
EU type approval
Pressure Equipment Directive (PED)
EN 12952-11, EN 12953-09: Requirements made on limiting
equipment for boilers
Functional safety
SIL 2
IEC 61508 Functional safety of safety-related electrical/ electronic/
programmable electronic systems
TÜV type approval
VdTÜV Bulletin “Wasserstand 100” (Water Level 100):
Requirements made on water level limiting & control equipment.
Type approval no. TÜV · SHWS · XX-XXX (see name plate)
Contents of package
1 x Level switch LCS3051
1 x Installation manual
Contact your local Spirax Sarco representative. Details can be found on accompanying order /delivery
documentation or on our web site:
www.spiraxsarco.com
Returning faulty equipment
Return all items to your local Spirax Sarco representative. Ensure all items are suitably packed for transit
(preferably in the original cartons).
Please provide the following information with any equipment being returned:
1. Your name, company name, address and telephone number, order number and invoice and return
delivery address.
2. Description and serial number of equipment being returned.
3. Full description of the fault or repair required.
4. If the equipment is being returned under warranty, please indicate:
a. Date of purchase.
b. Original order number.
8. Technical assistance

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LCS3051 High Water Level Switch
Spirax Sarco Ltd
Runnings Road
Cheltenham
GL51 9NQ
United Kingdom
www.spiraxsarco.com