IFM LT30 Series User manual

Operating instructions
Electronic level and
temperature sensor
LT30xx
UK
05 / 2019
80264354 / 00

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Contents
1 Preliminary note...................................................................................................4
1.1 Symbols used ................................................................................................4
2 Safety instructions ...............................................................................................5
3 Functions and features ........................................................................................6
3.1 Application area ............................................................................................6
3.2 Restriction of the application area ................................................................6
4 Getting started .....................................................................................................6
4.1 Example configuration 1 ................................................................................7
4.2 Example configuration 2 ................................................................................8
5 Function...............................................................................................................9
5.1 Measuring principle level ...............................................................................9
5.2 Measuring principle temperature ...................................................................9
5.3 Operating principle / features of the unit......................................................10
5.3.1 Operating modes ................................................................................10
5.3.2 Notes on the integrated overflow prevention ...................................... 11
5.4 Display functions ......................................................................................... 11
5.5 Analogue function ........................................................................................12
5.5.1 Level measurement with overflow prevention ...................................12
5.5.2 Level measurement without overflow prevention ...............................14
5.5.3 Temperature measurement ................................................................15
5.6 Switching functions......................................................................................17
5.7 Offset for indicating the real level in the tank...............................................18
5.8 Defined state in case of a fault ....................................................................18
5.9 Extreme value memory................................................................................18
5.10 IO-Link .......................................................................................................18
6 Installation..........................................................................................................19
6.1 Installation instructions for operation with overflow prevention ..................20
6.2 Installation instructions for operation without overflow prevention ..............21
6.2.1 Installation in the inactive zone...........................................................21
6.2.2 Installation in the active zone .............................................................22
6.3 Other installation notes................................................................................23
6.3.1 Marking of the installation height .......................................................23
7 Electrical connection..........................................................................................24

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8 Operating and display elements ........................................................................25
9 Menu..................................................................................................................26
9.1 Menu structure.............................................................................................26
10 Parameter setting ............................................................................................27
10.1 Parameter setting in general .....................................................................27
10.2 Basic settings ...........................................................................................28
10.2.1 Assign process values to the outputs [SEL1] / [SEL2]......................28
10.2.2 Assign process value to the display [SELd]......................................28
10.2.3 Define unit of measurement for level [uni.L] .....................................28
10.2.4 Set the unit of measurement for the temperature [uni.T]..................28
10.2.5 Set the offset [OFS] ..........................................................................29
10.2.6 Set the medium [MEdI] .....................................................................29
10.2.7 Set the overflow prevention [OP]......................................................30
10.2.8 Adjust the overflow prevention [cOP]................................................30
10.3 Setting of output signals ............................................................................31
10.3.1 Set output function [ou1] for OUT1 (switching output) .....................31
10.3.2 Set output function [ou2] for OUT2 (analogue output) .....................32
10.3.3 Define switching limits [SP1] / [rp1] (hysteresis function) ................32
10.3.4 Define switching limits [FH1] / [FL1] (window function) ....................32
10.3.5 Scale analogue signal [ASP2] / [AEP2] ............................................32
10.3.6 Set switching delay [dS1] for switching output .................................33
10.3.7 Set switch-off delay [dr1] for switching output ..................................33
10.3.8 Define switching logic [P-n] for switching output .............................33
10.3.9 Define response of the outputs in case of a fault [FOUx] ................33
10.3.10 Configure display [diS]....................................................................33
10.3.11 Reset all parameters to factory settings [rES] ................................33
11 Notes on parameter setting via IO-Link ...........................................................34
12 Operation.........................................................................................................34
12.1 Operation indication...................................................................................34
12.2 Read the set parameters ...........................................................................35
12.3 Read / reset extreme value memory temperature .....................................35
12.4 Fast selection level / temperature..............................................................35
12.5 Error indications.........................................................................................36
12.6 Output response in different operating states............................................36
13 Technical data..................................................................................................37

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1 Preliminary note
1.1 Symbols used
►Instructions
> Reaction, result
[…] Designation of keys, buttons or indications
→Cross-reference
Important note
Non-compliance may result in malfunction or interference.
Information
Supplementary note.
13.1 Setting values [OFS]..................................................................................37
13.2 Setting ranges switching limits for level.....................................................37
13.3 Setting ranges switching limits for temperature.........................................37
13.4 Setting values [OP]....................................................................................38
13.5 Calculation aids [OP] .................................................................................39
13.5.1 Definition "from the cover“ ................................................................39
13.5.2 Definition "from the bottom“..............................................................39
13.6 Setting ranges [ASP2] and [AEP2] ............................................................40
14 Maintenance / cleaning / change of medium ..................................................40
14.1 Maintenance information for operation without overflow prevention .........40
15 Factory setting .................................................................................................41

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2 Safety instructions
• The device described is a subcomponent for integration into a system.
- The manufacturer of the system is responsible for the safety of the system.
- The system manufacturer undertakes to perform a risk assessment and to
create a documentation in accordance with legal and normative requirements
to be provided to the operator and user of the system. This documentation
must contain all necessary information and safety instructions for the operator,
the user and, if applicable, for any service personnel authorised by the manu-
facturer of the system.
• Read this document before setting up the product and keep it during the entire
service life.
• The product must be suitable for the corresponding applications and environ-
mental conditions without any restrictions.
• Only use the product for its intended purpose (→ Functions and features).
• Only use the product for permissible media (→ Technical data).
• If the operating instructions or the technical data are not adhered to, personal
injury and/or damage to property may occur.
• The manufacturer assumes no liability or warranty for any consequences
caused by tampering with the product or incorrect use by the operator.
• Installation, electrical connection, set-up, operation and maintenance of the unit
must be carried out by qualified personnel authorised by the machine operator.
• Protect units and cables against damage.
• The unit complies with the standard EN 61000-6-4. The unit may cause radio
interference in domestic areas. If interference occurs, the user must take
appropriate remedial actions.

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3 Functions and features
3.1 Application area
The unit was especially designed to meet the requirements of machine tool
building. It is especially suitable for monitoring coolant emulsions (also dirty) as
well as cutting and hydraulic oils.
The unit monitors 2 process values: level and temperature.
3.2 Restriction of the application area
• The unit is not suitable for:
- acids and alkalis
- hygienic and electroplating applications
- highly conductive and adhesive media (e.g. glue, shampoo)
- granulates, bulk material
- use in grinders (increased risk of formation of deposits).
• It is possible that foam of good conductivity is detected as level.
►Test proper functioning in an application test.
• For water and hydrous media with temperatures > 35 °C, install the unit in a
climatic tube (→ Accessories).
• For automatic medium detection (→ 5.3.1):
For media which are very inhomogeneous, separate from each other and thus
forming separation layers (e.g. oil layer on water), the following applies:
►Test proper functioning in an application test.
4 Getting started
For fast set-up, the example configurations described in the following can be used
for most applications. The indicated minimum distances apply exclusively to each
separately described case.

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4.1 Example configuration 1
Unit: LT3022 (probe length L= 264 mm)
Medium to be detected: Mineral oil
Operating mode: Manual media selection with overflow prevention
(factory setting) (→ 5.3.1).
Installation environment: Metal tank, installation to Fig. 4-1
►Install unit.
►Maintain the distances (x), (u) and (c):
x: min. 4.0 cm
u: min. 1.0 cm
c: max. 14.0 cm
►Ground sensor and tank via an electrical
connection (→ 7).
►Observe the parameter setting sequence:
- [MEdI] = [OIL.2] (→ 10.2.6)
- [OFS] = (u); e.g. (u) = 2.0 cm (→ 5.7)
- [OP] = Set the overflow prevention OP at a
distance (y) greater than 4.5 cm below
the mounting element.
For distances (y) smaller than 4.5 cm there
may be malfunctioning and error messages
during the adjustment process [cOP].
Fig. 4-1
OP
c
Step increment and setting range (→ 13.4).
Calculation aids for [OP] (→ 13.5).
►Adjustment of the overflow prevention OP to [cOP] (→ 10.2.8)
>The unit is ready for operation.
►Make further settings if necessary.
►Check whether the unit operates correctly.

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4.2 Example configuration 2
Unit: LT3023 (probe length L= 472 mm)
Medium to be detected: Coolant emulsion
Operating mode: Automatic medium detection (→ 5.3.1)
Installation environment: Metal tank, installation to Fig. 4-2.
►Install unit.
►Observe the distances (x), (u) and (c):
x: min. 4.0 cm
u: min. 1.0 cm
c: max. 23.0 cm
►Ground sensor and tank via an electrical con-
nection (→ 7).
►Observe the maximum permitted level (b).
A distance (a2) greater than 5.0 cm must be
observed between maximum level (b) and
mounting element.
Ensure distance (a2) by means of
appropriate mechanical measures (e.g.
overflow, ...) or by setting a threshold value
in the PLC.
►Observe the parameter setting sequence:
- [MEdI] = [Auto] (→ 10.2.6)
- [OFS] = (u), e. g. (u) = 1.0 cm (→ 5.7)
Fig. 4-2
c
bu a2
x
Switch point [SP1] can be used for monitoring the medium temperature.
►Unit must be reinitialised:
►Switch the operating voltage off and on again.
>The unit is ready for operation.
►Make further settings if necessary.
►Check whether the unit operates correctly.

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5 Function
5.1 Measuring principle level
The sensor determines the level according to the capacitive measuring principle:
• An electrical field [E] is generated
and influenced by the medium to be
detected. This change to the field
causes a measurement signal that
is electronically evaluated.
• The dielectric constant of a medium
is important for its detection. Media
with a high dielectric constant
(e.g. water) generate a strong
measurement signal, media with a
low dielectric constant (e.g. oils) a
correspondingly lower signal.
• The active measurement zone of
the sensor probe is composed of
16 capacitive measuring segments.
They generate measurement
signals depending on the degree of
coverage.
Fig. 5-1
A II
E
I: Inactive zone
A: Active zone (16 active segments)
E: Electrical field
Dimensions → Technical data sheet
5.2 Measuring principle temperature
The temperature is detected by a Pt element at the lower end of the probe and
electronically evaluated.
• Media without water content (e.g. oils) are directly (in contact with the medium)
detected.
• Hydrous media can also be directly detected up to temperatures of 35 °C.
For temperatures > 35 °C a climatic tube has to be installed for use in
hydrous media (→ 3.2). That means that temperature detection is indirect
(not in contact with the medium).
If a climatic tube is used, considerably increased response times have to
be expected.

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5.3 Operating principle / features of the unit
The unit can be installed in tanks of different sizes. Observe the notes on
installation.
2 outputs are available. They can be set separately.
OUT1 • Switching signal for level limit value / IO-Link
• Switching signal for temperature limit value / IO-Link
OUT2 • Analogue signal proportional to the level
• Analogue signal proportional to the temperature
To adapt to the present application select the required operating mode.
5.3.1 Operating modes
1. Manual media selection with overflow prevention (factory setting)
Recommended. Highest operational reliability
The medium to be detected is set manually [MEdI]. In addition, an integrated,
independently functioning overflow prevention is available.
2. Manual media selection without overflow prevention
Medium operational reliability
The medium to be detected is set manually as described under 1. However,
the overflow prevention is deactivated. For this reason, no adjustment is
required.
3. Automatic medium detection
Lowest operational reliability
Each time the operating voltage is switched on, the unit adjusts itself to the
medium and the installation environment.
For automatic media detection, no overflow prevention is available!
Automatic media detection can only function properly under certain
conditions (e.g. compliance with special mounting specifications,
restrictions for operation and maintenance).

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5.3.2 Notes on the integrated overflow prevention
With the parameter [OP] (OP = overflow prevention), one of the upper measuring
segments is defined as integrated overflow prevention.
• If the overflow prevention OP is activated, an adjustment to the installation
situation has to be made [cOP]. Otherwise, the unit is not ready for operation;
[ ] is displayed until readiness (→ 12.1).
• The overflow prevention OP can be deactivated ([OP] = [OFF]).
Deactivating the overflow prevention OP can impair the operational
reliability. For optimum operation and maximum operational reliability, we
therefore recommend to not deactivate the overflow prevention OP.
• The overflow prevention OP is the maximum limit of the measuring range. The
switch point [SP1] / [FH1] is always below [OP].
• The overflow prevention OP is not assigned to a separate output. It offers
additional protection and only switches if, as the level rises, the switching
output has not switched even though the corresponding switch point has been
exceeded (e.g. due to application-related malfunctions).
• Typically the overflow prevention OP reacts when the selected measuring
segment has been reached (a few mm before the set OP value).
• The overflow prevention OP replies immediately and without delay. The set
delay times (e.g. of a switch point directly below) have no effect on the overflow
prevention OP.
• The response of the overflow prevention OP is only indicated on the display
("Full" and indication of the current level change every second).
5.4 Display functions
The device displays the current level / the current temperature, optionally in
cm / inches or °C / °F. The display unit is defined by parameter setting. The set
unit of measurement and the switching status of the switching output are indicated
by LEDs.
The process value (level / temperature) can be changed temporarily in the operat-
ing mode.
►Briefly press [Set].
> Display of the other unit of measurement for 30 s; the respective LED is lit.

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5.5 Analogue function
The unit provides an analogue signal proportional to the level / temperature.
The analogue output (OUT2) can be configured:
• [SEL2] assigns the process value, level / temperature to the analogue output
(→ 10.2.1).
• [ou2] defines the output function of the analogue output, mA / V, (→ 10.3.2).
• In case of an internal fault, the output signal reacts according to the parameters
set in [FOU2].
5.5.1 Level measurement with overflow prevention
[SEL2] = [LEVL]
[OP] = [value ...] (overflow prevention OP activated)
[ou2] = [I] or [U]
Fig. 5-2 Fig. 5-3
OP positioned in the upper segment. OP shifted downward.
I [mA] / U [V]
L
20 / 10
4 / 0
AOP
I [mA] / U [V]
L
20 / 10
4 / 0
AOP
A: Active zone OP: Measuring segment overflow prevention
OP
L: Level
The measuring range is limited by the active measuring segment OP. If the level
reaches the measuring segment OP, the output signal jumps to its maximum value
(20 mA / 10 V).
The position of the measuring segment OP does not have any influence on
the gradient of the curve.

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[SEL2] = [LEVL]
[OP] = [value ...] (overflow prevention OP activated)
[ou2] = [InEG] or [UnEG]
Fig. 5-4 Fig. 5-5
OP positioned in the upper segment. OP shifted downward.
I [mA] / U [V]
L
20 / 10
4 / 0
AOP
I [mA] / U [V]
L
20 / 10
4 / 0
AOP
A: Active zone OP: Measuring segment overflow prevention
OP
L: Level
The measuring range is limited by the active measuring segment OP. If the level
reaches the measuring segment OP, the output signal jumps to its minimum value
(4 mA / 0 V).
The position of the measuring segment OP does not have any influence on
the gradient of the curve.

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5.5.2 Level measurement without overflow prevention
[SEL2] = [LEVL]
[MEdI] = [Auto] or [OP] = [OFF] (overflow prevention OP deactivated)
Fig. 5-6 Fig. 5-7
[ou2] = [I] or [U] [ou2] = [InEG] or [UnEG]
I [mA] / U [V]
L
A
20 / 10
4 / 0
I [mA] / U [V] I [mA] / U [V]
L
A
20 / 10
4 / 0
I [mA] / U [V]
A: Active zone L: Level
[MEdI] = [Auto] or [OP] = [OFF]:
Operating mode with the smallest operational reliability (→ 5.3.1)

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5.5.3 Temperature measurement
[SEL2] = [TEMP]
For temperature measurement the analogue signal can be scaled. The limits of
the measuring range for the lower output signal (analogue start point = ASP2) and
the upper output signal (analogue end point = AEP2) can be set.
Minimum distance between [ASP2] and [AEP2] = 22 C° / 40 °F.
If the measuring range is not reached or is exceeded by more than 10 %,
[UL] / [OL] is displayed (→ 12.1).
Output function current output:
Fig. 5-8 Fig. 5-9
Maximum measuring range at [ou2] = [I] Scaled measuring range at [ou2] = [I]
MAW MEW
20,5
20
4
3,8
T [°C/°F]
I [mA] I [mA]
T [°C/°F]MEWMAW AEP2ASP2
20.5
20
4
3.8
MAW: Initial value of the measuring range
MEW: Final value of the measuring range
ASP2: Analogue start point
AEP2: Analogue end point
Within the measuring range (-20...90 °C / -4...194 °F) the output signal is between
4...20 mA at [ou2] = [I] or 20...4 mA at [ou2] = [InEG] (without figure).
If the temperature value (T) is outside the measuring range, the output signal
reacts as below:
[ou2] = [I] [ou2] = [InEG]
T < MAW (ASP2) 3.8...4 mA 20.5...20 mA
T > MEW (AEP2) 20...2.5 mA 4...3.8 mA

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Output function voltage output:
Fig. 5-10 Fig. 5-11
Maximum measuring range at [ou2] = [U] Scaled measuring range at [ou2] = [U]
MAW MEW
10.3
10
T [°C/°F]
U [V] U [V]
T [°C/°F]MEWMAW AEP2ASP2
10.3
10
MAW = Initial value of the measuring range
MEW = Final value of the measuring range
ASP2 = Analogue start point
AEP2 = Analogue end point
Within the measuring range (-20...90 °C / -4...194 °F) the output signal is between
0...10 V at [ou2] = [U] or 10...0 V at [ou2] = [UnEG] (without figure).
If the temperature value (T) is outside the measuring range, the output signal
reacts as below:
[ou2] = [U] [ou2] = [UnEG]
T < MAW (ASP2) 0 V 10.3...10 V
T > MEW (AEP2) 10...10.3 V 0 V

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5.6 Switching functions
The unit signals via the switching output OUT1 that a set limit value has been
exceeded or that the level is below the limit value. The switching output can be
configured.
• Parameter [SEL1] assigns the process value, level / temperature to the output
OUT1 (→ 10.3.1).
Selectable switching functions:
• Hysteresis function / normally open (Fig. 5-12): [ou1] = [Hno].
• Hysteresis function / normally closed (Fig. 5-12): [ou1] = [Hnc].
First the set point (SP1) is set, then the reset point (rP1) with the requested
difference [rP1].
The hysteresis for the overflow prevention OP is fixed.
• Window function / normally open (Fig. 5-13): [ou1] = [Fno].
• Window function / normally closed (Fig. 5-13): [ou1] = [Fnc].
The width of the window can be set by means of the difference between
[FH1] and [FL1]. [FH1] = upper value, [FL1] = lower value.
Fig. 5-12 Fig. 5-13
SP
rP
L / T
t
L / T
FH
FL
1
0
1
0
FE
Fno
Fnc
L:
T:
Level
Temperature
HY:
FE:
Hysteresis
Window

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5.7 Offset for indicating the real level in the tank
The distance between tank bottom and lower edge of the probe can be entered as
offset value [OFS]. So display and switch points refer to the actual level (point of
reference = tank bottom).
For [OFS] = [0]: The reference point is the lower edge of the measuring
probe.
The set offset only refers to the display on the unit. It does not have any
effect on the analogue output and the process value transmitted via IO-
Link. The OFS parameter, however, is correctly transmitted via IO-Link and
can therefore be taken into consideration.
More information (→ 5.10).
5.8 Defined state in case of a fault
In case of a fault a state can be defined for each output. If a fault is detected or if
the signal quality is below a minimum value, the outputs pass into a defined state.
For this case the response of the outputs can be set via the parameters [FOU1] /
[FOU2] (→ 10.3.9).
5.9 Extreme value memory
The minimum and maximum values of the temperatures occurred since the last
memory reset can be retrieved via the menu items [Lo.T] and [Hi.T].
5.10 IO-Link
This unit has an IO-Link communication interface which requires an IO-Link-
capable module (IO-Link master) for operation.
The IO-Link interface enables direct access to the process and diagnostic data
and provides the possibility to set the parameters of the unit during operation.
In addition communication is possible via a point-to-point connection with a USB
adapter cable.
The IODDs necessary for the configuration of the unit, detailed information about
process data structure, diagnostic information, parameter addresses and the
necessary information about the required IO-Link hardware and software can be
found at www.ifm.com.

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6 Installation
Fig. 6-1
OP
c
L:
M:
c:
Probe length
Zone for mounting elements
Maximum outside length
u ... y:
OP:
B:
Minimum distances
Overflow prevention
Metal object inside the tank
Table 6-1
LT3022 LT3023 T3024
[cm] [inch] [cm] [inch] [cm] [inch]
L (probe length) 26.4 10.4 47.2 18.6 72.8 28.7
M (mounting zone) 14.0 5.5 23.0 9.1 36.0 14.2
c (max. outside length)*
* Applies to installation as shown (wall thickness of the tank lid was neglected; mounting
element does not protrude inside the tank).
Otherwise note mounting zone M.

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6.1 Installation instructions for operation with overflow
prevention
[MEdI] = [CLW..] or [OIL..]
[OP] = [value ...] (overflow prevention OP activated)
It is permitted to fix the mounting elements within the mounting zone (M)
(Fig. 6-1).
►Observe the maximum permitted outside length (c) according to Table 6-1.
►Observe the minimum distances according to Fig. 6-1 and Table 6-2.
►Observe the notes on the integrated overflow prevention OP.
The overflow prevention OP must:
1. be below the mounting element
2. be set at a minimum distance (y) to it.
The minimum distance is measured between lower edge mounting
element and OP value .
Table 6-2
MEdI = CLW.1 MEdI = CLW.2, OIL.1 MEdI = OIL.2
[cm] [inch] [cm] [inch] [cm] [inch]
x 2.0 0.8 3.0 1.2 4.0 1.6
u 1.0 0.4 1.0 0.4 1.0 0.4
y (LT3022) 2.5 1.0 3.5 1.4 4.5 1.8
y (LT3023) 4.5 1.8 5.5 2.2 6.5 2.6
y (LT3024) 6.0 2.4 7.0 2.8 8.0 3.2
v 4.5 1.8 4.5 1.8 4.5 1.8
w 4.0 1.6 5.0 2.0 6.0 2.4
Calculation aids for [OP] (→ 13.5)