BEKA BA678C, Руководство пользователя, Страница: 20 / 27

8. MAINTENENCE
The BA678C indicating temperature transmitter
should only be maintained by trained competent
personnel.
8.1 Fault finding during
commissioning
If a BA678C fails to function during commissioning
the following procedure should be followed:
Symptom Cause Check
No display or
output current
Incorrect wiring
Low supply
voltage
Wiring
That voltage
between terminals
5 & 6 is between 9
& 28V at all output
currents. Terminal
5 positive.
or between
15 .5 & 28V at all
output currents if
optional backlight
is fitted.
Digital display is
over or under
range showing
9.9.9.9.9
or
-9.9.9.9.9
with all decimal
points flashing.
Incorrect wiring of
THC or RTD input
Input is outside
specified range for
voltage or
resistance input.
Wiring and input
configuration.
Reconfigure digital
display.
Bargraph is over
or under range.
with scale
flashing, bargraph
displaying all or
just one segment.
Input is outside
specified range for
bargraph.
Reconfigure
bargraph display.
Digital display &
bargraph flashing
and 4/20mA fixed
at 3.6, 3.8 or
21.0mA
Sensor fault
detection has
been activated.
Sensor and input
wiring.
8.2 Fault finding after
commissioning
ENSURE PLANT SAFETY BEFORE STARTING
MAINTENANCE
If a BA678C fails after it has been functioning
correctly the following procedure should be followed:
Symptom Cause Check
No display or
output current
Wiring or power
supply fault.
Wiring
That voltage
between terminals
5 & 6 is between 9
& 28V. Terminal 5
positive.
or
15 .5 & 28V if
optional backlight
is fitted.
Digital display &
bargraph flashing
and 4/20mA fixed
at 3.6, 3.8 or
21.0mA
Sensor fault
detection has
been activated.
Sensor and input
wiring.
If this procedure does not reveal the cause of the
fault we recommend that the transmitter is replaced.
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