Elec tri cal Out puts (con tin ued)
n
The Model TA402A provides an Analog
Output Signal for interfacing with other
external devices (
i.e. PLC, Chart Recorder, etc.
).
This signal originates at the Flame Detector
and passes through “Signal IN” of the Trip
Amplifier, out “AO+” to the external device
and must be returned to “AO-” of the Trip
Amplifier. The signal from the Flame
Detector is a stepped 0 to 20mA signal:
0mA Fault Condition
2mA COPM Fault (FL310X only)
4mA Safe Condition
8mA IR Presence (FL3000, FL3100 only)
12mA UV Presence (FL3000, FL3100
only)
16mA Immediate indication of the
presence of flame radiation
20mA Sufficient Flame Radiation present
for the duration of a user specified
time delay in the Flame Detector
The Model TA402A interprets the analog
signal from the Flame Detector as follows:
0mA Fault Condition, The TA402A will
display a Fault Code & activate
the Fault LED and circuit.
2mA COPM Fault, The TA402A will
display a Fault Code & activate
the Fault LED and circuit.
4mA Safe Condition, The TA402A will
activate the Ready LED.
16mA Flame Radiation, The TA402A
will activate the A1 Alarm LED
and circuit and begin the Time
Delay count. If a 16mA (or
higher) signal is maintained
continuously for the period of
the Time Delay the TA402A will
activate the A2 Alarm LED and
circuit.
The maximum resistance load on the Analog
Signal loop, including the wire running from
the Flame Detector to the Trip Amplifier and
to any External Device, must not exceed 300
ohms.
If the Analog Output is not used to interface with
an external device, a jumper must be placed
between “AO+” & “AO-” on the rear terminal of
the Trip Amplifier (see section 3.3, page 10).
4.4 Accepting Alarm Conditions
Whenever a new alarm condition occurs the front
panel LED and open collector associated with that
alarm (LA1 or LA2) will flash. In addition, the
associated alarm outputs and the unaccept outputs
(TA402A, UA open collector & FM002A, UA
relay) will activate, unless they are already
activated. The flashing front panel alarm LED
and rear terminal open collector indicate that a
new alarm has been activated. New alarms
should be acknowledged or accepted. This is
accomplished with the Master Accept Button
located on the Facilities Module. Pressing the
Master Accept Button de-activates the UA
outputs and causes the associated front panel
alarm LED and rear terminal open collector to
stop flashing and energize.
NOTE: Latching alarms must be Accepted
before they can be Reset (see section 4.5).
There is a unique situation that may occur with
some frequency in certain applications. An alarm
may occur and the operator will accept this alarm
by pressing the Master Accept Button. If the
alarm output is latching and the condition at the
detector returns to normal (safe) the alarm output
will need to be reset. If, however, the alarm
output is accepted but not reset and that alarm
condition occurs again, the front panel LED, the
associated mimic open collector and the unaccept
outputs will reflash or re-activate. This gives the
operator an indication of a new alarm condition
that must be re-accepted.
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