OM AGSD-1
51
Alarms and Events
Situations may arise that require some action from the chiller or that should be logged for
future reference. A condition that causes a shutdown and requires reset is known as an
alarm
. Other conditions can trigger what is known as an
event
, which may or may not
require an action in response.
Faults
usually cause a shutdown but may not. All stop
alarms and events are logged.
Unit Stop Alarms
The alarm output and red button led are turned ON when any stop alarm occurs. They are
turned off when all alarms have been cleared.
Phase Volts Loss/GFP Fault
Alarm description (as shown on screen):
Unit PVM/GFP Fault
Trigger:
PVM 1 input is low and setpoint is Single-Point
Action Taken:
Rapid stop all circuits
Reset:
Auto reset when PVM 1 input is high
Evaporator Flow Loss
Alarm description (as shown on screen):
Evap Water Flow Loss
Trigger:
1.
Evaporator Pump State = Run AND
Evaporator Flow Digital Input = No Flow for time >
Flow Proof Setpoint AND at least one compressor running
2: Evaporator Pump State = Start for time greater than Recirc Timeout Set Point and all
pumps have been tried
Action Taken:
Rapid stop all circuits
Reset
: This alarm can be cleared at any time manually via the keypad or via the BAS clear
alarm signal.
If active via trigger condition #1 above:
When the alarm occurs due to this trigger, it can auto reset the first two times each day, with
the third occurrence being manual reset.
For the auto reset occurrences, the alarm will reset automatically when the evaporator state
is Run again. This means the alarm stays active while the unit waits for flow, then it goes
through the recirculation process after flow is detected. Once the recirculation is complete,
the evaporator goes to the Run state which will clear the alarm. After three occurrences, the
count of occurrences is reset and the cycle starts over if the manual reset flow loss alarm is
cleared.
If active via trigger condition #2 above:
If the flow loss alarm has occurred due to this trigger, it is always a manual reset alarm.
Evaporator Water Freeze Protect
Alarm description (as shown on screen):
Evap Water Freeze
Trigger:
Evap. LWT drops below evap freeze protect setpoint AND Unit State = Auto
Action Taken:
Rapid stop all circuits
Reset:
This alarm can be cleared manually via the keypad or via the BAS clear alarm
signal, but only if the alarm trigger conditions no longer exist.
Leaving Evaporator Water Temperature Sensor Fault
Alarm description (as shown on screen):
Evap LWT Sens Fault
Trigger:
Sensor shorted or open
Action Taken:
Rapid stop all circuits
Reset:
This alarm can be cleared manually via the keypad, but only if the sensor is back in
range.
Summary of Contents for AGS 225D
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