Maintenance And Fault; Maintenance, Cleaning; Rectify Faults; Shorten Suspension Cable - WIKA LH-20 Betriebsanleitung

6 Maintenance and fault rectification

6 Maintenance and fault

rectification

6.1 Maintenance, cleaning

If the instrument is used properly, no special
maintenance is required in normal operation.
In some applications, product buildup on the
sensor diaphragm can influence the measuring
result. Depending on the sensor and application,
take precautions to ensure that heavy buildup, and
especially a hardening thereof, is avoided.
If necessary, the transmitter has to be cleaned. In
this case, make sure that the materials are resistant
against the cleaning detergents.

6.2 Rectify faults

Check the 4 ... 20 mA signal
Connect a handheld multimeter in the suitable
measuring range according to the wiring plan.
?
4 ... 20 mA signal not stable
Level fluctuations
l
à
Adjust integration time via PACTware
No atmospheric pressure compensation
l
à
Check the capillariy and cut it clean
à
Check the pressure compensation in the
housing and clean the filter element, if
necessary
?
4 ... 20 mA signal missing
Connection to voltage supply wrong
l
à
Check connection and correct, if neces-
sary according to chapter "Wiring plan"
No power supply
l
à
Check cables for breaks; repair if neces-
sary
Operating voltage too low or load resist-
l
ance too high
à
Check, adapt if necessary
WIKA Operating instructions – Submersible pressure transmitter model LH-20
?
Current signal 3.6 mA; 22 mA
Electronics module or measuring cell
l
defective
à
Exchange the instrument or send it in for
repair
In Ex applications, the regulations for the
wiring of intrinsically safe circuits must be
observed.

6.3 Shorten suspension cable

Shorten the suspension cable individually. Proceed
as follows:
Remove the filter adapter from the capillary line
1
Cut the suspension cable to the requested
2
length with side cutters
Caution:
Do not squeeze the capillary cable, as this
will impair the pressure compensation. If
necessary, rework the capillary with a sharp
knife.
Remove approx. 10 cm of the cable mantle,
3
strip off approx. 1 cm of insulation from the
ends of the wires
Insert the filter adapter
4
The work steps are finished.

6.4 Instrument repair

You can find information for a return shipment
under "Service" on our local website.
If a repair is necessary, please proceed as follows:
Complete one form for each instrument
l
If necessary, state a contamination
l
Clean the instrument and pack it damage-proof
l
Attach the completed form and possibly also a
l
safety data sheet to the instrument
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