66 WGZ030D through WGZ200D OMM 1130
SET ALARM LIMITS
SET ALARM LMTS (1)
Low EVAP Pressure
Hold=XXXpsi
Unload=XXXpsi
The Hold and Unload 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). Reducing these time intervals will increase detrimental compressor cycling. It
is recommended that these settings not be changed.
SET ALARM LMTS (2)
High Cond Pressure
Unload= XX.XF
Stop=XXXsec
Unload is a limit alarm that unloads the unit at 370 psi in an attempt to prevent total shutdown from the
HighCondPr at 380 psi. The stage down is set at 370 psi. It is recommended that these settings not be
changed.
Stop (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.
LowEvPrDelay is a time delay on the low pressure trip that reduces nuisance low-pressure trips. The
default setting is 30 seconds.
SET ALARM LMTS (3)
GroundFault = N
PhaseVoltage = N
Low OATStartTMR=XXsec
GroundFault and PhaseVoltage entries are Y (Yes) or N (No) depending on whether the options are on the
unit.
CondFreeze is an alarm that reduces the chance of freezing the water in the condenser (when compressors
are not running). An alarm is registered and the condenser pump is energized at the same time. The
alarm setpoint is 34F saturated condenser temperature and it resets at +2F above the setpoint.
SET ALARM LMTS (4)
Evap Freeze = XX.XF
EvapFlowProff=XXXsec
Recirc Timeout=XXmin
Evap Freeze (the unit freeze protection shutdown) is actually a stop alarm and shuts off the unit when the
LWT reaches 36F. It is cleared by going to the CLEAR ALARM menu in the ACTIVE ALARM
hierarchy.
EvapFlowProof is the flow switch interlock. Closing the flow switch and therefore proving the existence
of chilled water flow resets this trip. It is recommended that these settings not be changed.
LowAmbientLock applies to units with air-cooled condensers and prevents unit operation below the
setting. The available range is -2F to 60F with a default of 35F.
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