Liscarroll Engineering LE-300 User manual

EST. 1973
Installation and Operating Instructions
for Installers and Service Engineers
Universal Tank Controller:
LE-300
Simply Better . . . by Design

2
Contents Introduction 5
1.1 Information about this operating instructions 5
1.2 Limitation of liability 6
1.3 Warning notices in these operating instructions 6
1.4 Device description 7
1.5 Type designation 7
1.6 Item supplied 8
1.7 Dimensions 8
1.8 Sensor dimensions and technical data 8
1.9 Technical data of control unit 9
2. Safety 10
2.1 General Information 10
2.2 Intended use 11
2.3 Wiring, screening, earthing 12
2.4 Electrical safety 12
3. Installation 13
3.1 Location and climatic conditions 13
3.2 Unpacking and storage 13
3.3 Installation of housing 13
3.4 Fitting the sensor 14
4. Electrical connection 15
4.1 Safety during installation 15
4.2 Procedure 15
4.3 Wiring 15-16
4.4 Connection diagram (Delivery conguration) 16
4.5 Wiring the digital inputs 17
4.6 Connection robot 17
4.7 Connection of external pressure sensor (optional) 18
5. Operation 19
5.1 Function overview 19
5.1.1 OFF mode (stand-by) 19
5.1.2 Cooling mode 19
5.1.3 Continuous stirring mode 20
5.1.4 Cleaning mode 20
5.2 The conguration software KONSOFT. 21
5.3 Guideline for the initial installation / parameterization 22
5.4 Setting the date and time 23
5.5 Operation in levels 24
5.5.1 Operating levels explanation 25
5.6 Operation of working level 26
5.6.1 Button functions 26
5.6.2 Meaning of the LED‘s 28
5.6.3 Operation modes 30

3
LE-300
6. Cleaning 35
6.1 Abort of the cleaning 35
6.1.1 Cleaning cycle completely nished 35
6.1.2 Manual abort of the cleaning 35
6.1.3 Abort of the cleaning due to faults 35
6.1.4 Power failure during cleaning 36
6.2Cleaning parameters / conguration (r-level) 36-38
6.3 Cleaning parameters / step times (n-level) – ECO main wash 39
6.4 Cleaning parameters / step times (d-level) – Descale wash 40
6.5 Cleaning parameters / step times (u-level) – Quick wash 41
6.6 Cleaning parameters 42
6.7 Cleaning parameters 43
6.8 Water and Detergent Usage Eco Wash 5 Cycle: 30 Minutes 44
6.9 Water and Detergent Usage Eco Wash 5 Cycle: 50 Minutes 45
6.10 Water and Detergent Usage Eco Wash 5 Cycle: 75 Minutes 46
6.11 Water and Detergent Usage DESCALE Wash 5 Cycle: 33 Minutes 47
6.12 Water and Detergent Usage DESCALE Wash 5 Cycle: 50 Minutes 48
6.13 Water and Detergent Usage DESCALE Wash 5 Cycle: 75 Minutes 49
7. Tank monitor and general fault handling 50
7.1 Description of tank monitor operation 50
7.2 Tank monitor: Milk removal YES or NO 52-53
7.3 Tank monitor: Handling multiple faults 54
7.4 Tank monitor: Display fault memory 54
7.5 Listing fault codes and their description 55
7.5.1 Critical tank monitor alarms (red) 55
7.5.2 Informative tank monitor alarms (green) 56
7.5.3 System alarms - cleaning 57
7.5.4 System alarms - cooling 60
7.5.5 System alarms - external sensors 61
7.5.6 System alarms in general 61
7.5.7 Test alarm 61
8. Setting of parameters 62
8.1 Change and save parameter values 62-63
8.2 General cooling parameters (C-level) 64
8.3 Level “General cooling parameters” (c parameters) 65-66
8.4 Level “Extended cooling parameters” (P parameters) 67-73
8.5 Level “Extended cooling parameters” (P parameters) 74-77
8.6 Adjustment of Cleaning Step Times 78
8.7 Setting of parameters 79
8.8 Cleaning parameters / conguration (r-level) 80-81
8.9 Setting of parameters 82
8.10 Cleaning parameters / step times (n-level) – ECO main wash 83
8.11 Cleaning parameters / step times (d-level) – Descale wash 84
8.12 Cleaning parameters / step times (u-level) – Quick wash 85
8.13 Setting of parameters 86-87
8.14 Setting of parameters 88-90
8.15 Setting of parameters 91-92
8.16 Setting of parameters 93
8.17 A Parameters 94-100
8.18 Setting of parameters 101-103
8.19 Setting of parameters 104
8.20 A Parameters 105

4
9. Other information – General 106
9.1 Buttery valve (manual or pneumatic) 106
9.2 Safety switch for manual buttery valve 106
9.3 Sensor correction procedure 107
9.4 Function second temperature sensor 107
9.5 Test functions 18
9.5.1 Test alarm F99 18
9.5.2 Function test “Do-Not-Load LED” and “external alarm light” 18
9.6 Procedure following power failure 108-109
9.7 Power pack or operation via external power supply 110
9.8 Agitator monitoring module (optionally) 111
9.9 I/O Expansion module ESIO 112
9.10 USB module ESUSB 112
9.11 Integrated multifunction-time relay 112-114
9.12 Safety chain for ‘remote start’ functions 115
9.13 RS485 interface 116
9.14 General measures when using electronic control systems 117-118
9.15 Robot control 119
9.15.1 Cleaning release by robot 120
9.15.2 Compressor switch-on delay / pre-agitating 121
9.15.3 Compressor lock via digital input (by robot) 121
10. Other information - Cooling 122
10.1 Automatic start continuous agitating or cooling mode 122
10.1.1 Automatic start to continuous agitating mode after exiting cooling mode 122
10.1.2 Automatic start to cooling mode after successful cleaning 122
10.2 Different variants for cooling start delay 123-124
10.3 Emergency cooling / Sensor fault 125
10.4 Level alarm during cooling (Fault code F52) 125
10.5 Connection /Parameterization external analogue pressure sensor 126
10.6 Tanks and silos with multiple cooling stages (cooling step control) 127
10.7 Tank overow protection 128
10.8 Anti-freezing protection by means of low pressure monitoring 129
10.9 Thermal protection - / Fault monitoring compressor [P72] 130
10.10 Fault messages low pressure (F80) 131
10.11 Fault Messages High Pressure (F81) 131
11. Other information - Cleaning 132
11.1 Detergent supply via beaker 132
11.2 Setting of a break in the cleaning programme 132
11.3 Level control setting 133
11.4 Relay function ‘set level 2 to relay’ 133
11.5 Function of pressure switch – Effect on pump and heater 134
11.6 Air in the cleaning pump -> automatic venting 134
12. Other information - Tank monitor 135
12.1 Activation delay tank monitor [H90] 135
12.2 EMAIL-, alarm + remote maintenance module ESIPM 135
12.3 SMS, alarm + remote maintenance module ESGSM 135
13. Appendix 1- Display Unit LE 300 wiring information 136-147

5
LE-300
1. Introduction
1.1 Information about this operating instructions
These operating instructions are intended for the use by Installation
Engineers, installers or service technicians of the LE-300 universal tank
control. This manual contains all necessary suggestions, Information,
recommendations and advice for the safe and proper installation and
commissioning of the tank control. It is only with the knowledge of this
operating instruction that errors in the tank control system can be avoided and
a trouble-free operation is guaranteed.
Read the assembly instructions carefully and adhere to the recommendations
described in order to ensure proper operation. In addition, the local accident
prevention regulations and general safety regulations are to be observed for
the eld of application of the tank control.
When delivered, the parameterization of the LE-300 does not necessarily
correspond to the intended use. This must be adjusted accordingly during
the installation.
Basically, the installer of the system is responsible for the commissioning
of the control.
Operation instruction for the operator
The plant engineers, the installer or the service technician must prepare
operating instructions for the operator of the tank control (farmer). In this
case the parameterization of the delivery state must be clearly documented.
We recommend to only document those parameters which the operator of the
tank control needs.
When preparing the operating instructions for the operator the local
regulations have to be observed – see chapter “Safety”.
These operating instructions include important technical and safety
information. It is vital to carefully study all these instructions before the
installation of the control or in case of any other work with the control!
The manufacturer accepts no liability for errors and reserves the right to make
technical changes at any time. All rights reserved.
NOTICE for storing the operating instructions
This instruction manual is part of the product and must always be readily
available for the service technician.
NOTICE
WARNING

6
1.2 Limitation of liability
The proper function of the LE-300 depends on many external factors
on which the manufacturer has no inuence. The manufacturer accepts
no liability for any damages on the milk cooling tank, the connected
components or the milk. The integrated tank monitor supports only
the control of the milk quality and does neither absolve the farmer (as
operator of the milk tank) nor the driver of the milk collecting truck
from the duty of care. Both parties have to ensure that the milk is
transportable before it is removed from the tank.
All information and instructions in this manual have been compiled taking into
account the applicable standards and regulations, the state of the art and our
long-term experiences.
WELBA GmbH does not assume any liability for damages due to:
- Non-observance of the installation instruction
- Improper use
- Installation by unqualied staff
- Non-professional installation by third parties
- Unauthorized modications
- Technical modications
- Use of unapproved spare parts (e.g. batteries)
Otherwise, our general terms and conditions as well as the terms of delivery
of WELBA GmbH and the legal regulations valid at the time of conclusion of
the contract are applicable.
We reserve the right to make technical changes in the context of improving
the properties of use and further developments.
Important safety information in these assembly instructions are identied
by symbols. These instructions on occupational safety must be adhered to
and followed. In these cases, behave particularly carefully in order to avoid
accidents, personal injury and property damage.
In addition to the information in these assembly instructions, the general and
local safety and accident prevention regulations must also be observed and
instructed!
Nature and source of danger
This warning signs warns of an imminent danger to health and life of people.
Failure to comply with this warning will result in extremely serious injuries,
including death.
Nature and source of danger
This warning signs warns of a possibly dangerous situation for the health of
people. Failure to observe these warning notices can result in serious injuries,
including death.
Nature and source of danger
This warning sign warns of a possibly dangerous situation for the health of
people. Failure to observe these warnings can lead to minor or moderate
injuries.
Note
General notes contain application tips and particularly useful information, but
no warnings about dangers.
1.3 Warning notices in these operating instructions
DANGER!
WARNING
WARNING
ATTENTION
NOTICE

7
LE-300
NOTICE These operating instructions contain important technical and safety
information. Please read carefully before installation and before any work
on or with the regulator.
These instructions have been compiled with maximum care and attention.
However, their content does not constitute an assurance of product features.
The manufacturer cannot be held liable for errors and may at any time make
changes serving technical progress. All rights reserved.
1.4 Device description
The LE-300 is an universal tank control unit that combines various basic
functions in one unit
a milk cooling thermostat
- an extensive cleaning control
- an extended robot interface
- an extended tank monitoring system
All functions can be parameterised separately and universally.
The control unit has various operating modes:
- OFF mode (tank is empty)
- Cooling mode
- Continuous stirring mode
- Cleaning mode
WELBA “KONSOFT”
The free of charge conguration Software KONSOFT provides a simple
parameterization and updating of the LE-300 as well as a comfortable
evaluation of the determined data.
See section 5.2
The KONSOFT PC-Software has been thoroughly tested and has proven itself
hundreds of times in customer use. Despite all care, we point out that the use of the
free PC-Software is at your own risk. WELBA does not accept any liability for damages
or loss of data resulting from the installation or use of the Software.
NOTICE
1.5 Type designation The type designation of your controller is attached to the holder frame.

8
1.7 Dimensions
1.8 Sensor dimensions and technical data
Sensor element KTY 81-210
Bush material 1.4301 (V2A)
Bush length 40 mm
Bush diameter 6,0 mm +/- 0,1
Cable material PVC
Measurement range -10 .. 70° C
Cable length standard 2 metres
A Sensors other than our standard type are available on request (different
bush form or cable length).
Some of the options are shown here.
1.6 Item supplied - Controller LE-300
- Holder
- Rubber seal
- Sensor TF1A-2
- Fixing screws
- Any optional accessories ordered.

9
LE-300
Operating voltage 230V AC +/-10%, 50/60 Hz
Relay contact 12 performance relays
expandable by 6 relays*
max. switching current 6 x each 6A AC1 - 250V AC
4 x each 10A AC1 - 250V AC
2 x each 12A AC1 - 250V AC
max. current per terminal 12A - 250V AC
max. switching voltage 250V AC - 50..60 Hz
Display 13 mm LED-Display, 4 digits
Display range -999 .. 9999
LED switching status displays 3 mm LED
Number of sensor inputs 1 or 2
Measurement range -5° .. +95°C
Temperature resolution 0,1°C
Sensor input for KTY 81-210 (optionally PT-100)
Control mode two-step controller
Hysteresis* 0,1 K .. 99,9 K ((standard adjusting 0.7 K)
Water detection via 2 independent level monitors
Target temperature standard adjusting 8°C
T1* Target temperature T2* standard adjusting 4°C
Digital inputs 8 (via optocoupler)
expandable by 5 digital inputs*
Interface 2x RS-485
Supply ext. pressure sensor 12V +/-3V max. 40 mA
Connection Plug-in screw connections
for cables up to 2.5 mm²
Housing
- Front dimension 177 x 106 mm
- Front panel cut out 157 x 97 mm
- Insertion depth 45 mm
Protection The control is open on the rear, as it is
designed for installation in a closed
housing IP 64
- Housing front IP 00
- Rear IP 20
Electrical safety Protection class II,
Overvoltage category III, pollution degree I
Environment specications:
- Operation temperature 0° .. +50°C
- Storage temperature -20° .. +70°C
- max. humidity 75% (no dew) 75% (no dew)
1.9 Technical data of control unit
Technical data subject to change.
* via I/O expansion module ESIO-001

10
2. Safety
2.1 General Information
The plant engineering company, the installer or the service engineer must
prepare operating instructions for the operator, taking account of the
controller’s parameters as supplied.
We recommend referring only to the parameters which the end user
needs for safe operation.
In preparing the operating instructions for the end user, especially the
chapter on “Safety”, account must be taken of local regulations.
The parameter settings of the LE-300 as supplied do not correspond
to the intended use. This can lead to undened behaviour by individual
components when the system is commissioned.
For this reason, no actuators should be connected when starting
operation. Load circuits should be separated.
The general principle is that the plant constructor is responsible for
putting the controller into operation.
IMPORTANT NOTICE ON LIABILITY
The faultless function of the LE-300 depends on many external factors, which
the manufacturer has no inuence on. The manufacturer assumes no liability
for damage to the milk cooling tank, the connected components or the milk.
The integrated tank monitor thus only sup-ports the milk quality and does
not release the farmer (as operator of the milk cooling tank) or the driver of
the milk collecting truck from the duty of care. These must ensure, before
withdrawing from the tank, that the milk is transportable.
WARNING
NOTICE
WARNING
DANGER!
IMPORTANT NOTICE ABOUT THE ACCUMULATORS
See section 9.7
(required when using the tank monitor)
The life of the accumulators is limited. The built-in accumulators must be
replaced by new ones every two years at the latest.
Only (!) charged accumulators of the following specication may be used:
1.2 V NiMh - size AA (min. 2.000 mAh)
DO NOT USE BATTERIES !!! EXPLOSIVE !!!!!

11
LE-300
These operating instructions contain important technical and safety in-
formation. Please read carefully before installation and before any work
on or with the regulator.
It is the duty of the party commissioning the system to ensure compliance
with the following guidelines.
The universal tank controller may only be installed by an authorised specialist,
observing all local safety requirements.
Access to the environment when connected must be restricted to specialised
personnel.
Universal tank controllers contain live components. They must be built into the
plant in such a way that contact with such live components is impossible.
The controller is not suitable for use in explosive atmospheres. Danger of
explosion. Use only outside areas subject to explosive atmospheres.
The device must not be used if the housing or connection terminals are
damaged.
No uids must penetrate the housing.
The universal tank control may not be exported to the USA without the
manufacturer’s express permission!
These operating instructions contain important technical and safety in-
formation. Please read carefully before installation and before any work
on or with the regulator!
Universal tank controllers LE-300 are designed to control heating systems,
condensing units, alarms, fans, etc. in milk cooling tanks as well as to monitor
milk quality. Furthermore, connected milking robots can be controlled. Any
other use of the device is permitted only with prior written permission from
the manufacturer.
The controller is intended only for incorporating into machinery, display
panels or switchboxes etc. and when tted corresponding to protection class
2 (double or reinforced insulation). It is only allowed to be put into operation
in installed state. The use of the control is permitted in devices of protection
class 1 and 2. The controller must not be modied or converted in any way.
The universal tank controller is ready for use only when the parameters have
been set appropriately. Its use before this has been done would have no
benets and could also damage the equipment or adversely affect the milk to
be temperature-controlled.
Responsibility for the faultless functioning of the connected devices lies with
the plant engineer or the installer or the service engineer who has installed
and commissioned the LE-300.
The device is tted with a resistance temperature sensor.
The controller is not suitable for use in explosive atmospheres. Danger of
explosion. Use only outside areas subject to explosive atmospheres.
The LE-300 fulls the EC requirements for electromagnetic compatibility
(EMC) and the Low Voltage Directive (LVD).
The safety components meet the VDE regulations
WARNING
NOTICE
2.2 Intended use

12
When selecting wiring materials and installing and connecting the
temperature controller to the electricity supply, account must be taken of DIN
VDE 0100 “Erection of power installations with rated voltages below 1000” or
the relevant national regulations (e.g. based on IEC 60364).
- Wherever possible, keep input, output and supply leads and sensor
cable physically separate from each other and do not lay them parallel
to each other.
- Mains voltage cables and low-voltage cables must not be laid in one cable.
- Use screened and twisted interface and sensor cables.
- Earth the screening of temperature sensors unilaterally in the switchbox.
- Ensure correctly wired potential equalisation.
- The controller itself and the associated control circuits and load circuits
must be protected separately and in accordance with the local regulations.
- The separate protection of the control- and load circuit must be carried
out ac-cording to local conditions!
- In order to prevent destruction of the relay or semiconductor relay outputs
in the event of a short-circuit, the load circuit should be fused to the
maximum permissible output current.
- As well as incorrect installation, wrong parameter settings can also
adversely affect the correct functioning of the controller. For this reason,
safety devices that are independent of the controller should always be
used, e.g. high and low pressure valves or temperature limiters.
Account should be taken of the local safety regulations in this connection.
- The load circuit (relay outputs K1 to K12) must be fused in accordance
with the connected components.
- The connection of external voltages to the digital inputs can lead to the
destruction of the control.
- Caution: All cables to the digital inputs must be shielded and kept as short
as possible. EMC.
Important note concerning the external fuse
- The transformer, which is installed in the LE-300, has a two-chamber
safety winding, which is only short-circuit-proof due to the built-in thermal
protection. If the temperature exceeds 145 ° C, there is a risk of damage!
Protect control unit with an external fuse of 160mA!
2.3 Wiring, screening, earthing
2.4 Electrical safety
NOTICE

13
LE-300
It is essential not to install the device under the following conditions:
- severe jolting, vibration or magnetic elds
- permanent contact with water
- relative humidity of more than 90%
- sharply uctuating temperatures (condensation)
- dust, ammable gases, vapours, solvents,
- operation in an aggressive atmosphere (ammonia or sulphur fumes) - risk of
oxidation
- operation in the immediate vicinity of radio transmitters with high levels of
spurious radiation.
A physical separation between the device and inductive consumers is
recommended.
If the packaging is damaged or something is missing, do not t the
temperature controller. In this case please contact Welba.
If you keep the temperature controller for a period before using it, store it in a
clean dry place at a temperature of between -20°C and +70°C.
For xing the housing please follow the instructions:
- Place the seal carefully in the groove. Ensure it is not twisted.
- Insert the housing from the front through the switchboard cut-out.
- Attach the holding frame in the rear position as shown by the picture.
- Fasten the housing by using the screws provided.
3. Installation
3.1 Location and climatic conditions
3.2 Unpacking and storage
3.3 Installation of housing

14
3.4 Fitting the sensor
WARNING The sensor cable must not be chafed or kinked.
There must be no substantial mechanical pressure on the sensor tube.
Do not place the sensor and the high-voltage cable in the same cable
conduit (not even within the switchbox).
Temperature range sensor cable -10°C .. +70°C
The LE-300 has been designed for connection to various types of sensor (see
technical data). It can function properly only if one of those sensor types is
installed and the parameters are correctly set.
When setting the temperature controller parameters (and whenever the
sensor is replaced) the “actual value correction” [Parameter C91] must be
adjusted so that the temperature measured corresponds to that shown on the
display. A reference thermometer should be used for this purpose.
See section 9.3
Pay attention to the permitted temperature range for sensor cable exposure.
Changing the sensor cable length
lf it is necessary to shorten or lengthen the sensor cable on installation (or
if a sensor other than the one supplied is to be tted), the “actual value
correction” parameter must be adjusted accordingly. See section 9.3

15
LE-300
In order to avoid injury to persons or damage to connected components,
connections must in all cases be undertaken in the following order!
- Pull out all the controller’s plug-in terminals.
- Put the controller in position in the housing or switchboard.
- Connect all components and sensors in accordance with section 4.4
(Circuit diagram) to the plug-in terminals.
(Do not yet plug the terminals into the controller!)
- Connect the mains cable to plug-in terminal A1 / A2.
- Plug terminal A1/ A2 into the controller.
- Close the switchbox and turn on the mains voltage.
- Switch on the controller and set the parameters
(possibly using the optional WELBA-KONSOFT conguration software).
- Plug the pre-cabled plug-in terminals of the components into the
controller.
- Close the switchbox.
Before connecting ensure that the mains voltage is the same as indicated
on the device’s type plate.
Incorrect electrical connection can cause damage to the regulator and to
the equipment.
The temperature controller should be disconnected from the mains
voltage while connecting plant components or the sensor.
No appliances with current levels in excess of the maximum values
indicated in the technical data should be connected to the relay contacts.
No other consumers may be connected to the controller’s mains
terminals.
4. Electrical connection
4.1 Safety during installation
4.2 Procedure
4.3 Wiring
WARNING
WARNING
Correct wiring in accordance with the information in the accompanying
description and local regulations is essential. Take particular care to ensure
that the AC supply is not connected to the sensor input or other low-voltage
inputs or outputs.
The various relay contacts may only be connected with uniform tension.
Use copper wire (except for the sensor connection) and ensure that all supply
leads and connection terminals are dimensioned to suit the relevant current
rating.
When connecting the controller and selecting the wiring materials to be used,
it is essential to comply with the provisions of DIN VDE 0100 “Erection of
power installations with rated voltages below 1000” or the relevant national
regulations.
Furthermore, all connections must comply with the relevant VDE regulations
or corresponding national regulations.

16
4.3 Wiring (continued)
4.4 Connection diagram (Delivery conguration)
- Within the two relay groups (K3 to K6) and (K9 to K12), the respective
relays are connected with each other on one side. They connect the
respective volt-age which has been connected at the feed point
(terminals 8 and 17) to the load.
- Compressor, cleaning pump and heater must not be connected directly
to the relays on the control unit. These must be switched by additional
contactors. In individual cases, it must be checked whether additional
motor protection switches or other safety devices are to be installed.
- Contactors are to be tted with an RC protective circuit.
- Connection of the digital inputs:
- Only the output signal of the control provided at terminal 38 must be
connected to the digital inputs (via potential-free switching contacts)!
- Electrical connections must be as shown in the diagram below.
- Use cable bushes.
- Make sure that cables cannot chafe.
- Observe relay current rating.
- In all cases use contactors for pump, compressor and heater.
- Do not feed digital inputs with external voltage! Use potential-free switches.
ATTENTION => Delivery conguration
The nal assignment of components to the relay outputs is set in the A
parameters (A1 to A20). See section 8.11
The assignment of components to the digital inputs is set in the A parameters
(A21 to A33). Section 8.18

17
LE-300
4.5 Wiring the digital inputs
4.6 Connection robot(optional)
Terminals 39 to 46 are digital optocoupler inputs. These are used to monitor
and process external switching contacts. These switching contacts must be
potential free! The signal provided by the controller at terminal 38 must be
fed separately to each individual switching contact.
If the LE-300 and the robot have a separate power supply, the robot can still
be stopped (by corresponding connection) in the event of power failure.
Robot requires an active signal to stop (high-active)
- [A41] = 0: In the event of a power failure, the robot is NOT stopped
(Connection to terminal 6 / 4)
- [A41] = 2: In the event of a power failure, the robot is stopped
(Connection to terminal 6 / 5)
Robot needs to lose the signal to stop (low active)
- [A41] = 1: In the event of a power failure, the robot is stopped
(Connection to terminal 6 / 4)
- [A41] = 3: In the event of a power failure, the robot is not stopped
(Connection to terminal 6 / 5)

18
4.7 Connection of external presure sensor (optional)
Terminals 27 | 28 | 29 must be used only for the connection of an external
pressure sensor. See section 10.5
Internal power supply
via terminal 27
12 V +/- 3 V - max. 40 mA
If the sensor cannot be powered
by internal power supply:
Use external power supply.
NOTICE

19
LE-300
5. Operation
5.1 Function overview The LE-300 is a universal tank control unit which combines all the basic
functions in one device:
- milk cooling control
- comprehensive cleaning control
- an extended robot interface
- an extended tank monitor
All basic functions can be selected and operated from the working level.
The control unit can also be adapted to a wide range of different system types
and sizes. This takes place through the thematically organised parameter
levels.
Within the working level the control unit differentiates between various
operating modes:
5.1.1 OFF mode (stand-by)
Shows the current time.
All LEDs are out
(Exceptions: robot, outlet valve and tank monitor LEDs may be lit)
All output relays are deactivated
(Exceptions: robot, outlet valve and tank monitor alarms may be active)
CAUTION: The control unit is live even when switched off!
5.1.2 Cooling mode
(can NOT be started from cleaning mode)
Two freely denable target temperatures can be selected by pressing a
button.
If the milk temperature exceeds the selected target temperature (T1 or T2)
by the hysteresis value, the compressor contactor and agitator are switched
on automatically. Once the target temperature is attained, the compressor
contactor switches off, while the agitator continues to run for the set “after-
stirring“ period.
During cooling breaks the agitator switches on periodically, in accordance with
the set “pause time”, in order to ensure an even temperature throughout the
milk.
Independently of this, during cooling, short or long “intermediate stirring”
can be switched on by pressing a button.
Cooling can be triggered in different ways:
- manually using the “START COOLING“ button
- via digital input “Remote start to cooling“ (by robot or external button)
- automatically following cleaning (only in conjunction with robot)
Cooling now starts in accordance with the pre-set starting mode: Immediately
or after a cooling start delay, with periodic cooling boosts, etc.

20
5.1.3 Continuous stirring mode
From OFF mode, the agitator can be switched on by pressing a button and
then switched off again by pressing the OFF button.
Parameter [C25] can be used to set the time after which the agitator is to
switch off automatically.
The countdown can be interrupted at any time using the OFF button.
If [C25] is set to ‘0’, the agitator will run continuously, but can be switched off
at any time using the OFF button.
From the continuous stirring mode, it is possible to switch directly to the
cooling or cleaning mode by pressing a button.
5.1.4 Cleaning mode
(can NOT be started from cooling mode)
The cleaning timer controls the water intake by time or level, as desired. All
running times (heater, pump, detergent injection) can be set separately. The
automatic switchover from acidic to alkaline detergent is also adjustable.
The LE-300 controls the different processes and times fully automatically.
Following a power failure the control unit will restart in the mode it was in
before. See also section 9.6
Robot interface
Depending on the parameter settings, the control unit includes a built-in robot
inter-face with the following functions:
“Robot start / stop“ and
“Buttery valve open / closed“
These functions are controlled via the keypad.
Tank monitor function
During the entire cooling and cleaning process, the built-in tank monitor
keeps check on the correct operation of all components, in order to guarantee
the perfect state of the milk.
In particular, the following are monitored:
- minimum and maximum milk temperatures during cooling
- power failure (optionally power pack required!)
- agitator function (optionally agitator monitoring module required
- minimum and maximum temperatures during cleaning
- etc.
Any faults are indicated by two LEDs, and associated fault codes ash in the
display.
In the case of errors which may jeopardise the milk quality, the red LED “Don’t
add milk” lights up.
5.1 Function overview (continued)