10. ACCESSORIES
10.1 External keypad
For applications requiring the Rate Totaliser to be
adjusted or calibrated in Zone 2 or 22, without the
need for a risk analysis when a flammable
atmosphere may be present, an optional control
cover fitted with an external intrinsically safe keypad
is available.
This keypad maintains the enclosure ingress
protection and accidental push button activation can
be prevented by use of a menu security access
code, see section 6.18.
10,2 Units of measurement & instrument
identification.
The BA354NE Rate Totalisers is fitted with a blank
escutcheon around the liquid crystal display. This
can be supplied printed with any units of
measurement and tag information specified at the
time of ordering. Alternatively, the information may
be added on-site via an embossed strip, dry transfer
or a permanent marker.
To gain access to the display label remove the
terminal cover by unscrewing the two 'A' screws
which will reveal two concealed 'D' screws. If the
instrument is fitted with external keypad, also
unscrew the two 'C' screws securing the buttons and
un-plug the five way connector. Finally unscrew all
four 'D' screws and carefully lift off the front of the
instrument. The location of all the screws is shown
in Fig 4.
Add the required legend to the display escutcheon,
or stick a new pre-printed self-adhesive escutcheon,
which is available from BEKA associates, on top of
the existing escutcheon. Do not remove the original
escutcheon.
The BA354NE Rate Totaliser can also be supplied
with a blank or custom laser engraved stainless
steel plate secured by two screws to the front of the
instrument enclosure. This plate can accommodate:
1 row of 9 alphanumeric characters 10mm high
or 1 row of 11 alphanumeric characters 7mm high
or 2 rows of 18 alphanumeric characters 5mm high
10.3 Alarms
CAUTION
These alarms outputs should not be used
for critical safety applications such as an
emergency shut down system.
The BA354NE Rate Totaliser can be supplied with
factory fitted dual alarms with solid state, single pole
outputs. Each output may be independently
configured as a rate or total, high or low alarm with a
normally open or normally closed output in the non-
alarm condition.
When the 4/20mA current powering the Rate
Totaliser is removed both alarm outputs will open
irrespective of configuration. The open circuit
condition should therefore be chosen as the alarm
condition when designing an alarm system. Fig 10
illustrates the conditions available and shows which
are fail safe.
When an alarm occurs an alarm annunciator on the
Rate Totaliser display is activated and if required the
rate or total display causing the alarm can alternate
between the measured value and the alarm channel
identification ‘ALr1’, ‘ALr2’ or ‘ALr1-2’ if both alarms
are activated by the same variable.
Fig 10 Alarm outputs
Configurable functions for each alarm include
activation from rate display or total display,
adjustable setpoint, hysteresis, alarm delay and
alarm silence time.
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