Precision Digital PD650 - Manual (Page 13)

Model PD650 Large Display Process Meter Instruction Manual
13
FAIL-SAFE
OPERATION Relay coils are energized in non-alarm condition. In case of
power failure, relays will go to alarm state. Fail-safe operation
may be disabled, by removing jumper J5 located on the
Options Board.
AUTO
INITIALIZATION When power is applied, relays assigned to total will reflect the
state of the accumulated total value in memory. Relays
assigned to process/rate will reflect the state of the input to the
meter.
RELAYS RESET
Total relays reset
1. When total is reset to zero, if set up for external total reset
2. After delay has elapsed, if set up for internal total reset
3. Manual any time, if set up for external total reset (via user
supplied external contact closure at terminals AK and CM
or front panel ACK button)
Note: Manual reset resets all manually resettable relays.
Process/rate
relays reset
1. Automatic reset only
2. Manual reset only, at any time
3. Automatic plus manual reset at any time
4. Manual reset only after alarm condition has been
corrected
Automatic reset: Relays will automatically reset when the
input passes the reset point.
Manual reset: It can be performed via user supplied external
contact closure at terminals AK and CM or front panel ACK
button. Manual reset resets all manually resettable relays.