BEKA BA314NG, Manual

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8. MAINTENANCE
8.1 Fault finding during commissioning
If a BA314NG Tachometer fails to function during
commissioning the following procedure should be
followed:
Symptom Cause Check:
No display No power supply,
or incorrect wiring.
Note: Terminals 2,
6 & RS2 are
interconnected
within the
instrument.
That there is
between 10 and
30V on terminals 1
& 2 with terminal 1
positive.
Tachometer is
receiving power but
pulse input
indicator not
rotating
No input pulses,
incorrect input
configuration,
incorrect linking of
terminals 3 & 4.
Input configuration.
Linking of
terminals 3 & 4.
That input signal
polarity is correct.
Pulse input
indicator rotating,
but incorrect speed
display
Incorrect speed
display calibration.
5CALE
.
5
t-bA5E
Pulse input
indicator rotating
but missing or
incorrect
run-time display.
Run-time display is
not activated.
Tachometer speed
display is less than
clip-off value.
Remote reset
switch contacts
closed.
di5P-2
is activated
See 6.8
If HOLD
annunciator is
activated, enter
smaller
Clip-off
value. See 6.13
That ‘RESET’
annunciator is not
activated. If it is,
check reset wiring
and switch.
Unstable
Tachometer
display.
Noisy pulse input
signal.
Eliminate source of
electrical noise.
Increase debounce
and/or display filter.
See 6.12
Unable to enter
configuration
menu.
Incorrect security
code.
That the correct
security code is
being used.
See 6.18
Contact BEKA if
code is lost.
Clip-off does not
function.
Clip-off has
automatically been
reset to zero
following
calibration change.
Reconfigure
clip-off.
See 6.13
Alarms do not
function.
Alarms have been
disabled following
calibration change.
Re-enable both
alarms.
See 9.3.4
8.2 Fault finding after commissioning
EN 60079-17 Electrical installations inspection and
maintenance permits live maintenance in Zone 2 if a
risk analysis demonstrates that this does not
introduce an unacceptable risk. The removal of
covers [opening of Ex n instrument enclosure] is
permitted if this can be done without contaminating
the interior of the instrument with dust or moisture.
Some end-users may prefer not to permit live
maintenance to minimise risk.
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
Live maintenance within the hazardous area
should only be performed when it is
permitted by risk analysis, or when there is
no risk of a flammable atmosphere being
present.
If a BA314NG Tachometer 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
30V on terminals
1 & 2.
Pulse input
indicator not
rotating.
No input pulses. Output from
sensor.
Wiring between
sensor and
Tachometer.
Pulse input
indicator rotating,
run-time display
not functioning.
HOLD annunciator
activated.
Input below
clip-off threshold.
Adjust
Clip-off
threshold.
Unstable rate
display
Noisy pulse input
signal
Locate source of
electrical noise, or
increase
debounce and
rate display 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 BA314NG Tachometers
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. Inspection
frequency should be adjusted to suit the
environmental conditions.
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