ACS Control-System GmbH | www.acs-controlsystem.de | [email protected] | Eggenfelden | Germany
KAK / KLK
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Application field
The filling level limit switch
KAK
resp. KLK is used, to evaluate one or two filling levels resp. limit levels in
electrically conductive liquids with a conductivity of minimum 5µS/cm resp. a resistance of maximum 200k
.
The device is also useable as overflow protection in container with liquids, for the realization of a two-position-
control e.g. for pump control or also as dry run protection.
The conductivity also of aggressive filling liquids can be detected, at process temperatures from
-40 °C to +100 °C, at pressures from -1 bar to +10 bar.
The version
KAK
is the standard type for general applications, whereas the version
KLK
is especially conceived
for food applications.
The following variants are available:
Relay output version with wide range power supply from 20...253V
AC/DC
,
for two-channel or
s mode with two relay changeover contacts, resp.
Relay output version with wide range power supply from 20...253V
AC/DC
,
for one-channel or
s mode with two relay changeover contacts, resp.
Switching output version with direct voltage power supply 24V
DC
10%,
for one-channel or
s mode with one PNP switching output.
Function
Measuring principle
The filling level limit switch
KAK
resp.
KLK
is mounted in the wall of the container or of the pipe by using the
respective process connection or installed over the filling liquid by using a suitable mount.
The alternating voltage, that is generated by the integrated electronic is than applied either between the
electrode rods or between the electrode rods and the metallic wall of the container resp. pipe that is connected
to the metallic process connection.
Due to the use of a alternating voltage the corrosion at the electrode rod and the electrolytic decomposition of
the filling liquid is avoided.
As soon as the electrically conductive filling liquid makes a connection between the electrodes resp. between
the electrode and the metallic wall of the container resp. pipe, an alternating current flows, that causes a
decrease of the alternating voltage.
Signal evaluation
An evaluation circuit supervises this alternating voltage. A voltage drop is detected and the evaluation circuit
switches the relay resp. relays resp. the PNP switching output, depending on the set safety function.
The switching state of the output resp. outputs is indicated at the top side of the device by two yellow resp. at
the version with PNP switching output by one red LED’s.
Switching delay
In some applications it is necessary to compensate heavy signal fluctuations that may be produced by mixing
machines or at fill-in resp. emptying of containers, to avoid spurious switching actions.
The device is equipped with a switching delay of one second.
This delay time effects both channels separately, at activation and deactivation of the output signals.
Sensitivity range
For the adjustment of the response threshold to the conductivity of the liquid the filling level limit switch can be
adjusted by a multi-turn-trimmer
The detectable resistance is from 0
and 200,0 k
resp. 5µS/cm at the relay output version resp. 0
and
100,0 k
resp. 10µS/cm at the PNP switching output version.
