KROHNE OPTISOUND 3010 C, Handbook

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7 Maintenance and fault rectification
OPTISOUND 3010 C • Four-wire 4 … 20 mA/HART
30504-EN-220310
7 Maintenance and fault rectification
7.1 Maintenance
If the device is used properly, no special maintenance is required in
normal operation.
The cleaning helps that the type label and markings on the instrument
are visible.
Take note of the following:
•
Use only cleaning agents which do not corrode the housings, type
label and seals
•
Use only cleaning methods corresponding to the housing protec-
tion rating
7.2 Rectify faults
The operator of the system is responsible for taking suitable meas-
ures to rectify faults.
The device offers maximum reliability. Nevertheless, faults can occur
during operation. These may be caused by the following, e.g.:
•
Sensor
•
Process
•
Voltage supply
•
Signal processing
The first measures to be taken are to check the output signal and
evaluate fault messages via the display/adjustment module. The
procedure is described below.
Connect a multimeter in the suitable measuring range according to
the wiring plan. The following table describes possible errors in the
current signal and helps to eliminate them:
Error Cause Rectification
4 … 20 mA signal
not stable
Level fluctuations Set damping via the display and adjustment module
4 … 20 mA signal
missing
Electrical connection faulty Check connection according to chapter " Connection steps "
and if necessary, correct according to chapter " Wiring plan "
Voltage supply missing Check cables for breaks; repair if necessary
Operating voltage too low or
load resistance too high
Check, adapt if necessary
Current signal
greater than 22 mA
or less than 3.6 mA
Electronics module in the
sensor defective
Exchange the instrument or send it in for repair
In Ex applications, the regulations for the wiring of intrinsically safe
circuits must be observed.
Maintenance
Cleaning
Reaction when malfunc -
tion occurs
Causes of malfunction
Fault rectification
Check the 4 … 20 mA
signal