McQuay AWS User Manual

38 KOMAC00607-09EN
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:
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:
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: Evaporator LWT or EWT drops below evaporator freeze protect set point.
If the sensor fault is active for either LWT or EWT, then that sensor value cannot
trigger the alarm.
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.
Evaporator #1 Water Freeze Protect
Alarm description (as shown on screen): Evap#1 Water Freeze
Trigger: Evaporator LWT read from Evaporator #1 LWT probe drops below
evaporator freeze protect set point AND sensor fault is not active.
Action Taken: Rapid stop of circuits #1 and #2
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.
Evaporator #2 Water Freeze Protect
Alarm description (as shown on screen): Evap#2 Water Freeze
Trigger: Evaporator LWT read from Evaporator #2 LWT probe drops below
evaporator freeze protect set point AND sensor fault is not active
Action Taken: Rapid stop of circuits #3 and #4
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.
Evaporator Water Temperatures Inverted
Alarm description (as shown on screen): Evap Water Inverted
Trigger: Evap EWT < Evap LWT - 1 deg C AND at least one circuit is running
AND EWT sensor fault not active AND LWT sensor fault not active] for 30
seconds
Action Taken: Pumpdown stop on all circuits
Reset: This alarm can be cleared manually via the keypad.
Leaving Evaporator Water Temperature Sensor Fault
Alarm description (as shown on screen): Evap LWT Sens Fault

McQuay AWS Specifications

General

Brand	McQuay
Model	AWS
Category	Chiller
Language	English