Maintenance And Fault Rectification; Maintenance, Cleaning; Rectify Faults; Shorten Suspension Cable - WIKA LH-20 Manual De Instrucciones

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6 Maintenance and fault
rectification
6.1

Maintenance, cleaning

If the device is used properly, no special mainte-
nance is required in normal operation.
In some applications, product buildup on the
sensor diaphragm can influence the measuring
result. Depending on the sensor and appli-
cation, 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 multimeter in the suitable measuring
range according to the wiring plan.
4 ... 20 mA signal not stable
Cause
Level fluctuations
No atmospheric pressure
compensation
4 ... 20 mA signal missing
Cause
Connection to voltage
supply wrong
No power supply
Operating voltage too
low or load resistance
too high
20
Rectification
Adjust integration time via
PACTware
Check the capillariy and
cut it clean
Check the pressure com-
pensation in the housing
and clean the filter ele-
ment, if necessary
Rectification
Check connection and
correct, if necessary ac-
cording to chapter "Wiring
plan"
Check cables for breaks;
repair if necessary
Check, adapt if necessary
WIKA Operating instructions - Submersible pressure transmitter model LH-20
Current signal 3.6 mA; 22 mA
Cause
Electronics module or
measuring cell defective
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:
1. Remove the filter adapter from the capillary
line
2. Cut the suspension cable to the requested
length with side cutters
Caution:
Do not squeeze the capillary cable, as
this will impair the pressure compensati-
on. If necessary, rework the capillary with
a sharp knife.
3. Remove approx. 10 cm of the cable mantle,
strip off approx. 1 cm of insulation from the
ends of the wires
4. Insert the filter adapter
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
•
If necessary, state a contamination
•
Clean the instrument and pack it damage-
proof
•
Attach the completed form and possibly also
a safety data sheet to the instrument
7

Dismount

7.1

Dismounting steps

Warning:
Before dismounting, be aware of
dangerous process conditions such as
e.g. pressure in the vessel or pipeline,
high temperatures, corrosive or toxic
Rectification
Exchange the instrument
or send it in for repair