Spirax Sarco LCR2251 User manual

IM-P693-02 EMM Issue 2 1
LCR2251 Level Controller
LCR2251
Level Controller
Installation and Maintenance Instructions
IM-P693-02
EMM Issue 2
850144-01
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-P693-02 EMM Issue 2
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LCR2251 Level Controller
The equipment may only be installed, electrically connected and commissioned by suitable persons
with the relevant instruction/training.
Maintenance and modification may only be performed by authorised staff who have undergone
specific instruction/training.
Danger
The terminal strips of the equipment are live during operation! There is a risk of
serious injury due to electric shock!
Always cut off the power supply to the equipment before installing, removing or
connecting terminal strips!
Important
The name plate specifies the features of the equipment. Do not commission or operate
any item of equipment that does not have its own specific name plate.
Directives and standards
VdTÜV Bulletin "Wasserstand 100" (Water Level 100)
The LCR2251 level controller, in combination with the LP20/LP21/PA420 level transmitter, is type
approved to the VdTÜV Bulletin "Water Level 100".
The VdTÜV "Wasserstand (=Water Level) 100" describes the requirements for water level control
and limiting equipment for boilers.
LV (Low Voltage Directive) and EMC (Electromagnetic Compatibility)
The equipment conforms to the requirements of the Low Voltage Directive 2014/35/EU and the
EMC Directive 2014/30/EU.
ATEX (Atmosphère Explosible)
The equipment must not be used in potentially explosive atmospheres, in accordance with European
Directive 2014/34/EU.
1. Safety information

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LCR2251 Level Controller
2.1 Intended use
The LCR2251 level controller is used in combination with the LP20/LP21/PA420 level transmitter as a limit
switch and water level controller, e.g. in steam and water boiler systems, or in condensate and feedwater
tanks. The level controller indicates when a MIN and MAX water level has been reached, and controls a
control valve or pump.
2.2 Function
The LCR2251 level controller processes the level-dependent current signal from the LP20/LP21/ PA420 level
transmitter. This input signal is recognised by the controller as 0 and 100 % of the boiler measuring range,
and shown as an actual value on the 7-segment LED display.
The level controller works with an electro-pneumatically actuated control valve as a continuous controller
with proportional-plus-integral control(PI controller). In the event of deviations from the setpoint, it outputs
a current of 4-20 mA as manipulated variable Y.
Alternatively the controller can be configured to control a pump (on/off control) and transmit a 4 - 20 mA
signal to provide an external level indication (actual value output).
The controller can be configured for fill or discharge control.
If the MIN or MAX water level is reached, after the de-energizing delay the MIN or MAX output contact
switches over in the level controller, and the MIN or MAX LED lights up.
Faults in the level transmitter, the electrical connection or the settings are indicated as error codes on the
7-segment LED display. In the event of a malfunction, the MIN and MAX alarm is triggered.
If faults occur only in the LCR2251 level controller, the MIN and MAX alarm is triggered and the system is
restarted.
Parameters can be changed or the MIN/MAX alarm simulated by operating the push buttons.
2. General product information
Fig. 1

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LCR2251 Level Controller
3. Mechanical installation
3.1 Dimensions (approximate) in mm
12046
74
Item
1Upper terminal strip
2Lower terminal strip
3Housing
4Support rail TH 35, EN 60715
Fig. 2
3.2 Installation in control cabinet
The LCR2251 level controller is clipped onto a type TH 35, EN 60715 support rail in the control cabinet.
Fig. 2, item 4
4
1
2
3

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LCR2251 Level Controller
M 0,5A
LP20/ LP21/ PA420
IN 4-20mA
4 W
+ +
1 2 3 4 5 6 7 8
OUT 4-20mA
actual value/
control output
+12V
24 V ±20%
LOOP- LOOP+
+
3.3 Name plates
Fig. 3
Type
designation
Top
Bottom
Safety information
Manufacturer
Degree of protection
External fuse for output contacts
Ambient temperature
Output
contacts
Actual value output/control
signal for valve
Fuse, provided on site
Power consumption
Supply voltage
Connection
of level
transmitter
Approvals
Disposal
information
Serial number

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LCR2251 Level Controller
1E
2
4. Electrical installation
4.1 Wiring diagram
0.5 A (semi- delay)
1 3
4 5
8
7
6
Item
1MIN output contact, de-energizing delay 3 seconds.
2Pump output contact. Not used in continuous controller.
3MAX output contact, de-energizing delay 3 seconds.
4Supply voltage connection 24 Vdc with semi-delay fuse 0.5 A provided on site.
5Output 4-20 mA, manipulated variable Y for continuous controller or actual value output for ON/
OFF controller (pump control).
6Level transmitter LP20/LP21/PA420, 4-20 mA.
7Earthing point at auxilliary equipment (e.g.PA420/LP20/LP21).
8Central earthing point (CEP) in control cabinet.
Fig. 4
2
7

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LCR2251 Level Controller
4.2 Supply voltage connection
The equipment must be supplied with 24 Vdc from a SELV (Safety Extra Low Voltage ) power supply. An
external 0.5A semi-delay fuse must also be fitted.
This power supply unit must be electrically isolated from dangerous live voltages and meet the requirements
for double or reinforced insulation in accordance with one of the following standards:
EN 50178, EN 61010-1, EN 60730-1, EN 60950-1 or EN 62368-1.
4.3 Connection of output contacts
Wire the upper terminal strip 1(terminals 16-23), shown in Figure 1, according to the desired switching
functions. Provide an external slow-blow 2.5 A fuse for the output contacts.
When inductive loads are switched off, voltage spikes are produced that may have a major adverse effect on
the operation of control and measuring systems. Connected inductive loads must therefore have interference
suppression (RC combination) as per the manufacturer's specifications.
4.4 Connecting the level transmitter
For connecting the equipment, please use a screened, multi-core control cable with a minimum conductor
size of 0.5 mm2, e.g. LiYCY 2 x 0.5 mm2, maximum length 100 m.
Wire the terminal strip as shown in the wiring diagram (see Fig. 4).
Connect the screen as shown in the wiring diagram.
Route the connecting cable between items of equipment separately from power lines.
4.5 Output of manipulated variable Y or connection of actual
value output
For connection, please use a screened, multi-core control cable with a minimum conductor size of 0.5 mm2,
e.g. LiYCY 2 x 0.5 mm2, maximum length 100 m. Please note the load of max. 500 ohms.
Wire the terminal strip as shown in the wiring diagram (see Fig. 4).
Connect the screen as shown in the wiring diagram (Fig. 4). Route the connecting cable between items of
equipment separately from power lines.
Any item of equipment that you wish to connect to the terminals for the output of manipulated
variable Y or actual value output 4-20 mA must be certified to have at least double or reinforced insulation
to EN 50178, EN 61010-1, EN 60730-1, EN 60950-1 or EN 62368-1. between the current loop and live parts
of the equipment that are not supplied with safety extra-low voltage (SELV).
Important
Do not use unused terminals as support point terminals.
4.6 Tools
Screwdriver size 3.5 x 100 mm, fully insulated to VDE 0680-1.

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LCR2251 Level Controller
4.7 Connection of level transmitter
The LCR2251 level controller can be combined with the LP2, LP21 and PA420 level transmitter.
For connecting the equipment, please use a screened, multi-core control cable with a minimum conductor
size of 0.5 mm2, e.g. LiYCY 2 x 0.5 mm2, maximum length 100 m.
Connect the screen as shown in the wiring diagram
Important
-Please commission the equipment as described in the LP20/LP21/PA420
installation and operating manuals.
-Route the connecting cable between items of equipment separately from power
lines.

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LCR2251 Level Controller
5. Commissioning
5.1 Factory settings
-De-energizing delay: 3 sec. (factory set)
-Current input for the connection of LP20/LP21/PA420 level transmitter.
-MAX switchpoint AL.Hi = 80 %
-MIN switchpoint AL.Lo = 20 %
-Setpoint SP = 50 % (continuous controller) or SP.Hi = 60% and SP.Lo = 40% (ON/OFF controller)
-Proportional band Pb = 20 % of setpoint (continuous controller only)
-Integral action time ti = 0 s (continuous controller only)
-Dead band = +/– 5 % of setpoint (factory set)
-Filter = 2 s
-Fill control function
Code switch C: S1 = OFF, S2 = OFF, S3 = ON, S4 = ON See Figure 5
5.2 Changing factory settings
Danger
The upper terminal strip of the equipment is live during operation.
There is a risk of serious injury due to electric shock!
Always cut off the power supply to the equipment before installing, removing or
connecting the terminal strip!

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LCR2251 Level Controller
5.3 Changing the function and input of the level transmitter
The input and function are determined by the setting of code switch C. To make changes, you can access
the code switch as follows:
-Switch off the supply voltage.
-Remove the lower terminal strip (Fig. 5).
-Insert a screwdriver between the terminal strip and the front frame, to the right and left of the arrow
markings.
-Release the terminal strip on the right and left sides, by turning the screwdriver in the direction of the arrow.
-Remove the terminal strip.
Fig. 5
When your changes are complete:
-Refit the lower terminal strip.
-Switch the supply voltage back on. The equipment restarts
C
C