McQuay AGZ 035A, Инструкция по установке, эксплуатации и обслуживанию

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42 AGZ 035A through 065A IOMM AGZ-3
Figure 23, DIP SWITCH CONFIGURATION
REMOTE / DEMAND LIMIT
Global UNT Dipswitch Settings
Switch 1 2 3 4 5 6
On (10V) X X X X X
SW2
Off (2V) X
On (T) X
SW1
Off (V) X X X X X
Additional Global UNT Features
Remote Stop/Start
When the remote stop/start switch is open, the controller will be in the unoccupied mode. The unit
will be enabled when the remote start / stop switch is closed and will control at the leaving water
temperature setpoint.
Unoccupied Mode
When the remote start / stop input is opened, the unoccupied mode is initiated. The chiller will
maintain a higher leaving water temperature setpoint (default 70°F) if the chilled water circulation is
maintained. The unoccupied leaving water setpoint can be changed from the Zone Terminal.
Soft Start
Soft loading limits the number of available stages when the unit is started to prevent excessive power
consumption and possible overshoot of the leaving water temperature set point. Soft loading is in
effect whenever the unit is started from an “off” cycle. When stage up starts, the controller starts a
countdown timer to indicate how long the unit has been in the cool stage mode. The number of stages
allowed during soft loading is determined by the Soft Start Capacity. The duration of the soft load
sequence is determined by the Soft Start Timer. If the Soft Start Timer is set to zero, no soft loading
will take place. The Zone Terminal is required to change the Soft Start values.
Compressor Staging
The AGZ Scroll chiller has two refrigerant circuits and each circuit has two scroll compressors.
When the first stage of cooling is required, the #1 refrigerant circuit will start. This circuit will be the
first to start for the next ten Starts. The Global UNT controller will then select the #2 refrigerant
circuit to start first for the next ten starts. This cycle will continue and balance the number of starts
between the refrigerant circuits. This is an automatic lead / lag control.
The compressors are always started in a fixed order. Refrigerant circuit #1 has compressor #1 and
compressor #3. Compressor #1 will always start first on refrigerant circuit #1. Refrigerant circuit #2
has compressor #2 and compressor #4. Compressor #2 will always start first on refrigerant circuit #2.
There are four stages of cooling capacity on the Global Scroll chiller unit. The first stage of cooling
will be the first compressor of the lead refrigerant circuit. The second stage of cooling will be the
first compressor of the lag refrigerant circuit. Cooling stage three will always be compressor #3 and
cooling stage four will always be compressor #4.
Stage down is the reverse of the above paragraph.