19
The maximum equivalent capacitance and
inductance between each set of alarm terminals is:
Ci
= 20nF
Li
= 10µH
These figures must be subtracted from the
maximum permitted cable capacitance and
inductance specified by the system certificate of
the circuit connected to the alarm.
Fig 11 Typical alarm application
9.3.3 Programming and adjustment
When an alarm card is added to a BA327C or
BA328C indicator the main programme menu is
extended as shown in Fig 10. The additional
functions appear between Cond and C--P in the
main menu. For simplicity Fig 10 only shows the
additional functions available on alarm 1, but alarm
2 has identical facilities.
The following table summaries each of the alarm
programme functions and includes a cross
reference to more detailed information. Again
only the functions on alarm 1 are listed, but alarm
2 has identical facilities
Summary of programmable alarm functions
Display
Description of function
'EnbL
Alarm enable
Enables or disables the alarm function
without changing the alarm parameters.
See section 9.3.4
'SP1'
Alarm setpoint 1
Adjusts the alarm setpoint. The alarm
is activated when the indicator display
equals the setpoint.
See section 9.3.5
'HI.LO'
Alarm function
Defines whether the alarm has a high
or low function
See section 9.3.6
'no.nc'
Normally open or normally closed
output
Determines whether the single pole
alarm output is open or closed in the
non-alarm condition.
See section 9.3.7
'HStr'
Hysteresis
Adjusts the alarm hysteresis.
See section 9.3.8
'dELA'
Alarm delay
time
Adjusts the delay between the display
equalling the setpoint and the alarm
output being activated.
See section 9.3.9
'SIL'
Alarm silence time
Defines the time that the alarm output
remains in the non-alarm condition
following acceptance of an alarm.
See section 9.3.10
'AcSP'
Access setpoint
Sub-menu which enables direct access
to the alarm setpoints from the indicator
display mode, and defines a separate
security code.
See section 9.3.11
