Daikin McQuay AGZ-D - Page 30

30 AGZ 025D through 190D OMM 1087
Transitions between these states are shown in the following diagram.
T1 – Off to Preopen
 No compressors are running and any compressor on circuit is commanded to start (see unit capacity
control)

T2 – Preopen to Run
 5 seconds has passed
T3 – Run to Pumpdown
Any of the following are required:
 Last compressor on circuit is commanded to stop
 Unit State = Pumpdown
 Circuit switch is open
 Circuit mode is disable
 Circuit Pumpdown alarm is active
T4 – Pumpdown to Off
Any of the following are required:
 Evaporator Pressure < Pumpdown Pressure Value
 Unit State = Off
 Circuit Rapid Stop alarm is active
T5 – Run to Off
Any of the following are required:
 Unit State = Off
 Circuit Rapid Stop alarm is active
 A low ambient start attempt failed
T6 – Preopen to Off
Any of the following are required:
 Unit State = Off
 Unit State = Pumpdown
 Circuit switch is open
 Circuit mode is disable
 Circuit Rapid Stop alarm is active
 Circuit Pumpdown alarm is active