General Description
The CE series packaged air-cooled fluid chillers are designed for applications from 20°F to 70°F leaving fluid temperatures. The air cooled condensers are located atop the enclosure and are constructed with corrosion resistant materials. The chiller package includes multiple independent compressor/refrigeration circuits, an insulated stainless steel reservoir tank with interior thermal baffle, system pump, an independent air cooled condenser section per compressor circuit, and all operating and safety controls. Available as an option, the chiller can be packaged within a lighted walk-in equipment enclosure with a main access door.
The design of the chiller is matched specifically for the operating environment for which it is to be installed. The complete packaged chiller will be set in place, piped, and electrically connected.
Electrical
Compressor Module Electrical Enclosure
Each compressor section shall have a self contained operating and safety panel mounted inside a galvanized steel electrical enclosure. This panel will include the compressor starters, bypass pump starters, suction and discharge safety controls, and condenser fan VFD. The panel may be vented through a small vent opening on the bottom along with an exhaust fan. The enclosure includes hinged access with a locking “T” handle for easy access.
The process chiller is complete with single point wiring to the main tie in block. The electrical box and interior of the chiller are weatherproof by means of neoprene gaskets around all accessible openings.
Compressor Run-time Sharing
Each compressor module will utilize a relay to switch the compressors in the circuit with every off-cycle. Run-time will also be share by staging up the final compressors in reverse order. This ensures that compressors share run-time without a more complex logic control.
Fan Controls - Variable Frequency Drives (VFD)
Each compressor section is equipped with a 4-20ma pressure transducer located on the discharge line of the compressor. This transducer is directly wired to the Condenser Fan VFD which operates the two condenser fans per compressor section. The VFD, when powered, provides power to the transducer. The scaled pressure range within the VFD senses the discharge pressure of the compressor section and modulating the fan RPM appropriately. Each fan VFD is sized to handle the combined horsepower of both fan motors at design conditions. The VFD’s are rated to operate without de-rating to 122°F. An auto reset electromechanical pressure switch will not allow fan operation below 200 PSI.
The VFD’s also provide the following protections
- Short circuits within internal power supplies
- Short circuits between output phases
- Short circuits between output phases and ground
- Input phase loss
- Thermal protection against overheating and over-currents
- Under-voltage and over-voltage faults
Structural
Base Frame
The compressor, evaporator, condenser, tank, and pump are mounted on a heavy
duty steel base frame. The base frame is designed to provide superior
corrosion resistance, provide structural rigidity for seismic isolation requirements, and
allow mobility.
Enclosure
The enclosure shall be constructed of 2” extruded aluminum structural members connected together using cast aluminum corners. This modular framing system allows for a nearly screw-less exterior and superior structural integrity. Inside the chiller additional structure will be installed to additionally support the roof of the chiller, including the weight of the condenser sections. Lifting attachment point weights will be provided. |
