Trane CGAX/CXAX Manual page 49

Electrical panel
Unit is provided with a weatherproof control and
IP54 power panel with a single point connection with
disconnect switch. The disconnect switch is mechanically
interlocked to disconnect line power from power panel
accessible from the outside the chiller. All components
and control cables are numbered in accordance with
CEI 60750. The unit is equipped with a control power
transformer with two secondary control circuits:
• 230 V single phase connection for evaporator freeze
protection heaters and control board
• 24 V single phase connection for the human interface
control.
Each compressor is provided with a direct on line
starter factory mounted wired and tested. Soft Starter is
available as an option.
Hydraulic module (option)
Hydraulic module is integrated within the chiller frame
fi eld pipe connection is Victaulic and is outside of the
unit casing. Hydraulic kit has the following factory
mounted components:
• Single or double pump (in this case manifolded in
parallel one pump working as redundancy of the other)
factory mounted wired and tested with check valve in
the discharge. Options for standard and high pressure
shall be available.
• Pump crankcase shall be in polyamid impeller in
propylene dynamically balanced. Pump rated for 1MPa
working pressure.
• Pre-charged expansion tank.
• Flow switch.
• Water strainer able to retain particles above 1mm of
diameter.
• Water pressure relief valve.
• Electrical heater for freezing protection up to -10°C.
• Cold critical parts such the brazed plate evaporator
will be insulated with a closed cell foam insulation
againstcondensation of minimum 13 mm.
• Freeze protection shall be made by pump activation as
standard.
• As an option unit shall include a water buffer tank
insulated with closed cell foam of 13mm with
antifreezing protection. Buffer tank will fi t into the
chiller to minimize the system footprint.
CG-PRC026C-GB
Mechanical Specifications
Chiller Control System CH535
Chilled water temperature control is fulfi lled through a
microprocessor based controller monitoring water and
refrigerant temperature as long as refrigerant pressure.
Controller is able to generate adequate operational
diagnostics.
The Micropocessor based controller is supplied factory
mounted fully wired confi gured and tested in factory and
it ensures compressor and fan sequence (load control)
fault detection diagnostic and supervision.
The following features are present on the chiller
operational control
• High and low refrigerant pressure protection
• Load limit control to limit compressor loading on high
return water temperature
• Condenser fan sequencing with automatically cycling
in response to ambient condensing pressure.
• Compressors anti-short cycle timer protection
adjustable
• Automatic compressor lead-lag to even out run hours
and compressors starts
• Phase reversal/single phasing protection
• Low ambient lockout control with adjustable set point
• Integrated RS485 serial port to allow BMS connectivity
• Options for communication protocols: ModBus.
LonTalk and BACnet should be available
User display interface are provided on the external wall
of the chiller allowing complete graphic management
through icons and touchscreen display:
• Leaving chilled water setpoint adjustment
• Entering and leaving water temperatures display
• Condenser pressure per circuit
• Suction pressure per circuit
• Air ambient temperature
• Condensing temperature per circuit
• Suction temperature per circuit
Safety control readouts on the user display:
• Low chilled water temperature detection
• High refrigerant pressure
• Loss of chilled water fl ow
• Contact to external shut-down per circuit
• Motor current overload
• Phase reversal/unbalance/single phasing
• Failure of leaving water temperature sensor used to
drive the set point
• Compressor status (on/off)
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