14
Model TA502A
All of the relay contacts on the Model TA502A have a maximum rating of:
•
4A @ 250 VAC, 3A @ 30 VDC resistive
The following outputs have rear terminal open collectors:
•
A1 Alarm & LED Mimic
•
A2 Alarm & LED Mimic
•
Fault
•
UA - Unaccepted Alarm
•
FUA - Unaccepted Fault
•
CAL - Calibration Mode
All of the open collector outputs on the Model TA502A have a maximum rating of:
•
100 mA @ 35 VDC
The Analog Output Signal is used for sending field transmitter readings and status
information to remote devices. The TA502A has input impedance of 30 ohms. The
rear termination labeled “
Signal IN
” is part of the overall analog loop. The analog
signal is generated by the field device and passes through the Model TA502A. This
signal is a 0 to 21.7 mA current-signal with 4 to 20 mA being proportional to 0 to
100% of full-scale. When the field device is placed in calibration mode, the TA502A
will indicate
CA
if the current is 1 to 1.8 mA. (Standard Mode Only)
3.4 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 unaccepted outputs (TA502A, 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:
Alarms that latch, must be Accepted before they can be reset (see Section 3.5).
There is a unique situation, which 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
sensor returns to normal (safe), the alarm output will need to be reset. If the alarm
output is accepted but not reset and that alarm set point is exceeded again, the front