| Indication Units for LKB/LKLA, SRC,
ARC and ARC-SB |
Description
These indication units have to be installed laterally
between the air operated actuator and the valve.
The code numbers can be found in the Alfa Laval Product Program for the
different valve types.
All switches are EMC approved according to:
- - EN 50081-1, Generic emission standard, commercial and light
industry.
- - EN 50082-2, Generic immunity standard, industrial environment.
- - pr EN 60947-5-2, Product family standard: Proximity switches.
- - KA 2791.30 section 5.5 EMC, Tetra Pak Corporate Standard.
All tested requirements are met.
The pull-up or pull-down resistance in the input stage of the PLC must be
1-10 k ohms to ensure a proper reading of the signal from the sensors.
The wire connection can be different.
General description of different types of switches:
Micro switch
A micro switch can be compared with a standard light
switch but in a very small size and light in weight, a so called
subminature switch. It is activated mechanically by a roller leaf.
Standard function is normally open (NO), normally closed (NC) and is
always a digital signal (on/off).
The features of an environment proof sealed subminature switch are: Small
size and light in weight, with ample electrical capacity, precision
operation and long life. The micro switch used in indication units is
furthermore enclosed within a corrosion-resistant aluminium housing to
seal the switch contact and terminals against contamination.
Inductive proximity switch
This type of switch is a non-contact electronic switch. It
consists of an oscillator which creates high frequency electromagnetic
fields which radiate from the sensing face of the switch. Every
approaching conductive metal (damping target) causes a reduction of the
electromagnetic field. The result is a voltage change of the oscillator.
This analogue signal is converted by a Trigger circuit into an on/off
signal and the output is amplified.
Hall proximity switch
The Hall prox. switches are also non-contact electronic
switching elements. The sensor registers a magnetic field (north pole) and
consists of a Hall element (a type of a transistor) matching part, an
amplifier and an output part. The output signal is always on/off, digital
and the switching frequency is higher than the normal inductive switch or
the micro switch. The Hall prox. switch is ideal for modern computer
processing. NPN and PNP are two types of transistors. The difference is
the composition of positive or negative semi conductive materials.
| Signals: |
NPN |
PNP |
| Activated sensor |
0 |
1 |
| Non-activated sensor |
1 |
0 |
| Electrical data and connection |
|
Micro Switch |
|
|
For valve types:
LKB/LKLA |
Type:
Signal output:
Supply voltage:
Supply current: |
NO or NC.
On/off, digital.
24-55 (110) VDC/VAC.
Min. 100 mA.
Max. 1 A. |
 |
 |
3. Ø3 closed valve
2. Ø2 open valve |
| Note!
As the unit is not earthed it should not be used for voltage exceeding
55 V. |
 |
For valve types:
SRC, ARC and ARC-SB |
2. Ø2 open valve
3. Ø3 closed valve
A = One micro switch
B = Two micro switches |
|
Inductive proximity switch, IFM: |
 |
For valve types: |
- - Signal output:
- - Supply voltage:
- - Current rating:
- - Minimum load current:
- - Leakage current:
- - Voltage drop:
|
- - Digital, PNP/NPN (2 wire).
- - 20-110 VAC/10-110 VDC.
- - 150 mA.
- - 4 mA.
- - ≤ 0.6 mA.
- - ≤ 5 V.
|
SRC, ARC and ARC-SB |
|
|
PNP DC/AC |
NPN DC |
 |
A. Ø2 open valve
B. Ø1 +VDC/P VAC
C. Ø3 closed valve |
 |
A. Ø2 open valve
B. Ø1 0 (-) VDC
C. Ø3 closed valve |
Electrical data and connection
|
Hall proximity switch NPN, yellow coloured: |
|
- Signal output:
- Supply voltage:
- Supply current:
- Output:
- Activation:
- Temperature range:
|
Digital
5 to 24 VDC. Built-in regulator.
Max. 10 mA, normally 5 mA.
NPN open collector, max. 24 V, 25 mA.
Magnet, N-pole.
-20°C to 70°C. |
For valve types:
LKB/LKLA  |
|
Hall proximity switch PNP, green coloured: |
|
- Signal output:
- Supply voltage:
- Supply current:
- Output:
- Activation:
- Temperature range:
|
Digital
5 to 24 VDC. Built-in regulator.
Max. 15 mA, normally 10 mA.
PNP open collector, max. 24 V, 150 mA.
Magnet, N-pole.
-20°C to 70°C. |
For valve types:
SRC, ARC and ARC-SB |
|
Hall proximity switch PNP, grey coloured: |
|
- Signal output:
- Supply voltage:
- Supply current:
- Output:
- Activation:
- Temperature range:
|
Digital
20 to 30 VDC. Built-in regulator.
Max. 15 mA, normally 10 mA.
PNP open collector, max. 24 V, 150 mA.
Magnet, N-pole.
-20°C to 70°C. |
3. Ø3 closed valve
2. Ø2 open valve |
|
Technical data for female M12 plug |
|
- - Voltage:
- - Current:
- - Temperature:
- - PA 66
- - IP 67
- - PG9, cable diameter OD ≥ 6 ≤ 9mm
|
- - 250V AC/DC
- - 4A
- - -25 - +90°C
|
 |
|
The plug is 90° angled and can be turned 4 x 90° |
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