40
ACZ 010A through 039A
IOMM ACZ1
SET COMP SPs (2)
InterStageUp=XXXsec
InterStageDn=XXXsec
InterStageUp is the time delay since the last stage change before a compressor can stage on.
InterStageDn is the time delay since the last stage change before a compressor can stage off normally
(not by an alarm).
SET LIMIT ALARMS
SET ALARM LMTS (1)
LowEvPrHold=XXXpsi
LowEvPrUnld=XXXpsi
LowEvPrStop=XXXpsi
The LowEvPrHold and LowEvPrUnld have the same default value of 59 psi. If two compressors are
running, the LowEvPrUnld is in effect and the lag compressor will be shut off to unload the unit. If
one compressor is running, the LowEvPrHold is in effect and the lag compressor is prevented from
starting, thereby holding the unit capacity.
The last action to take place is the shutoff of all compressors running when the LowEvPrStop setting
is reached (default is 58 psi).
SET ALARM LMTS (2)
Evap Freeze= XX.X
°°°°
F
LowEvpPrDelay=XXs
EvapFlowProof=XXXsec
Evap Freeze (the unit freeze protection shutdown) is actually a stop alarm and shuts off the unit when
the LWT reaches 36
°
F. It is cleared by going to the CLEAR ALARM menu in the ACTIVE ALARM
hierarchy.
LowEvPrDelay is a time delay on the low pressure trip that reduces nuisance low-pressure trips. The
default setting is 30 seconds.
EvapFlowProof is the flow switch interlock. Closing the flow switch and therefore proving the
existence of chilled water or air flow resets this trip.
SET ALARM LMTS (3)
HighCondPr = XXXpsi
HiCondStgDn = XXXpsi
HighCondPr (the unit high-discharge-pressure shutdown) is a stop alarm that shuts off the unit when
the discharge pressure reaches the setting. The default setting is 380 psi. The HiCondStDn is a limit
alarm that unloads the unit in an attempt to prevent total shutdown from the HighCondPr. The stage
down is set at 370 psi.