BEKA BA334D, Manual

Page: 23 / 43

23
8. MAINTENANCE
8.1 Fault finding during commissioning
If a BA334D fails to function during
commissioning the following procedure should
be followed:
Symptom Cause Check:
No display Incorrect
wiring. Note:
Terminals 2, 4,
6 & 8 are
interconnected
within the
BA334D That there is
between 10 and
28V on terminals
1 & 2 with terminal
1 positive.
Flow indicator
not rotating
No input
pulses,
incorrect input
terminals
used, or
incorrect type
of input
selected If the BA334D has
been calibrated for
the correct input.
That input signal is
connected to
correct input
terminals and
correctly polarised.
Flow indicator
rotating but
incorrect rate
display
Incorrect
calibration
Input is below
clip-off
threshold
That rate scale
factor and
timebase are
correctly
programmed.
That clip-off
threshold is set
correctly.
Unstable rate
display
Noisy pulse
input signal Source of noise
and try to eliminate
or increase rate
filter.
Correct rate
display but
incorrect total
display
Incorrect
calibration
Remote reset
switch
contacts
closed
That total scale
factor is correctly
programmed.
That ‘RESET’
annunciator is not
activated. If it is,
check reset wiring
and switch.
Unable to
enter
programme
mode
Incorrect
security code That the correct
security code is
being used, or fit
security link in
override position.
See Fig 10.
Clip-off does
not function
and 4/20mA
output is
constantly
3.5mA
Clip-off &
4/20mA have
been
automatically
reset to zero
following
change of rate
display
calibration Re-enter required
clip-off and
4/20mA output
calibration.
Alarms do not
function
Alarms have
been disabled
following
calibration
change Re-enable both
alarms.
8.2 Fault finding after commissioning
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
Live maintenance is permitted on
intrinsically safe equipment installed in
a hazardous area, but only certified
test equipment should be used unless
a gas clearance certificate is available.
If a BA334D fails after it has been functioning
correctly, the following table may help to
identify the cause of the failure.
Symptom Cause Check:
No display No power
supply. That there is
between 10 and
28V on terminals 1
& 2.
Flow indicator
not rotating
No input
pulses Output from
flowmeter.
Wiring between
flowmeter and
BA334D.
Flow indicator
rotating, but
rate display
indicates zero
and there is
no totalsiation
Input below
clip-off
threshold Clip-off threshold
and if necessary
adjust.
Unstable rate
display
Noisy pulse
input signal Source of noise
and try to
eliminate, or
increase rate filter.
If this procedure does not reveal the cause of
the fault, it is recommended that the instrument
is replaced.
8.3 Servicing
We recommend that faulty BA334D rate
totalisers are returned to BEKA associates or
to your local BEKA agent for repair.
8.4 Routine maintenance
The mechanical and electrical condition of the
instrument should be regularly checked.
Initially annual inspections are recommended,
but the inspection frequency should be
adjusted to suit the environmental conditions.
8.5 Guarantee
Instruments which fail within the guarantee
period should be returned to BEKA associates
or our local agent. It is helpful if a brief
description of the fault symptoms is provided.
8.6 Customer comments
BEKA associates is always pleased to receive
comments from customers about our products
and services. All communications are
acknowledged and whenever possible,
suggestions are implemented.