Probes for use with the FLB1:
4.2 Function
If a conducting liquid is in the measuring cell, the feeding triangular voltage drives a current
through the liquid. The value of this current is proportional to the conductivity of the liquid in the
measuring cell. This value is detected by the evaluation unit and converted into the 4-20 mA
interface. The current is simultaneously converted into a voltage. This voltage is amplified
depending on the position of the limit switch and compared with a reference. If the result of the
comparison is greater than or equal to the reference, the relay is de-energised and the contacts
open the burner chain. The warning light "Fault" (Störung) lights up. If the conductivity of the
liquid drops below 78% of the set limit, the relay is energised again. The warning light "Fault" is
extinguished.
This function can be checked by pressing and holding down the "Test K" key. If there are
malfunctions of the system, e.g. due to power failure or a short circuit, the evaluation unit reacts as
if the conductivity has exceeded the limit value.
The warning light "U
B
" indicates that the operating voltage is present.
5. Design and installation FLB1
The device is supplied in a plastic plug-in housing for fitting into switch cabinets. The housing is
designed for quick fitting with a spring catch for the DIN EN 50022 standard 35 mm carrier rail and
for screw fixing on a mounting plate.
5.1 Installation dimensions and descriptions
Trimmer N for zero calibration
Trimmer T for temperature compensation
Trimmer Z for cell constant
1 = Conductivity limit setting
2 = Jack plug Ø 3.6 mm, for connection of a
measuring device for setting
Name
PS
TS
Connection
Feature
Type EL18
32 bar
239°C
G ½“
Piping-with flange mounting
EL22
32 bar
239°C
G ½“
frquently fitted with T-piece
EL23
80 bar
296°C
G ½“
protective tube installation
1
2
Cable feedthroughs
Base with
connecting terminals
Front view
Side view
Base Hood
Screws for loosening the Snap fastening for
Hood from the lower part for carrier rail
6
