INTRODUCTION
PETRA’s Residential Air-Cooled Smart chillers (PSC) with hermetic scroll compressors and R22 refrigerant, offer a wide range of sizes to meet customer requirements for different applications.
PETRA’s Smart chillers are designed to meet customer requirements by offering state of the art low sound, reliability, high energy efficiency and small physical footprints. The wide range of cooling capacities and flexible installation arrangement makes them easy to install and maintain.
PETRA’s Smart Chillers (PSC) are designed to be shipped as a complete factory package which are 100% test run in the factory. Unit capacities in this series range from 42 to 435 nominal tons at 50Hz and from 48 to 500 nominal tons at 60Hz with refrigerant R22. A wide choice of chiller capacities and options are available to meet most design requirements.
PETRA’s Smart Chillers PSC consist of highly efficient low-pressure drop coolers and high quality condenser coils with maximized airflow. Condenser coils are equipped with low noise fans with patented design fan and motor mounting.
PETRA’s Smart Chillers are equipped with an intelligent microprocessor controller to manage the unit’s performance for optimum efficiency at both full load and part load values.
OUTSTANDING FEATURES
Superior Efficiency
The Smart Chiller series exceeds the new ASHRAE 90.1 efficiency levels at both full load and part load efficiency.
Low Noise Chillers
The Smart Chiller series offers a low sound power level, measured in accordance with the BS IS0 3744 standard, by adopting a low noise scroll compressor and specially designed refrigerant piping.
Compact Physical Footprint
The Smart Chiller units feature compact footprints and the possibility for close- spacing installation to serve the areas that have space constrains
Outstanding Finishing
All copper pipes and headers are Acra Clad painted after being cleaned, to maintain pipe material and brazing protected against all external conditions.
All coil U-Bends are protected with a painted galvanized steel cover plate, mounted at the U-Bend coil side. The plate covers the whole U-Bend coil side.
Suction lines and other insulated pipes are wrapped in cheese-cloth and epoxy painted with the same color as compressor. This gives further protection for the insulation against weather and other factors.
Quality Assurance
To ensure the best performance, all the chillers in the Smart Chiller series are:
• Factory test run
• Produced in an ISO 9001-2000 listed manufacturing facility.
• Rated in accordance with ARI standard 550/590.
• Construction complies with ASHRAE 15 safety requirements.
Easy Installation
Installation is made quick and easy with complete factory wiring, easy listing provisions, factory installed options and start up. To eliminate potential start-up problems, a complete factory test run is performed on each unit.
Design Flexibility
The Smart Chillers meet the same high engineering and performance standards that are characteristics of all PETRA air-conditioning systems. A wide range of capacities and options for the Smart Chiller series are available to meet precise design requirements.
FEATURES AND BENEFITS
Scroll Compressor
The scroll compressor has two scrolls that are located in the upper part of the compressor above the motor, forming a completely enclosed compression chamber which leads to increased efficiency with fewer moving parts, less rotating mass and less internal friction compared to other types. It features excellent reduction in both noise and vibration.
Air Cooled Condenser
PETRA'S air-cooled condenser coils are designed to deliver their duties with optimum performance for all design conditions. Coils are manufactured from seamless copper tubes mechanically expanded into aluminum fins. All coils are air pressure tested at 450 Psi, under water to avoid leakage. They also undergo dry chemical cleaning after manufacturing for optimum system cleanness. Type-L, heavy wall seamless copper tubes are provided for coil headers. The condenser coils are hydrostatic pressure tested in accordance with the UL 1995 standard.
Direct Drive Condenser Fans
Condenser Fans are of the external rotor motor or direct driven type with sickle-shape blades, statically and dynamically balanced, selected for optimum efficiency and maximum sound power reduction.
The fan blades and guards are coated with an oven-baked, electrostatic, polyester powder coating.
Condenser Fan Motor
- All fan motors are of high efficiency external rotor motor with permanently lubricated bearing.
- Six pole induction type motor.
- Motors feature Ip54 protection, class F insulation provided with inherent motor protection.
Shell and Tube Cooler
High efficiency DX shell and tube type cooler with inner grooved tubes to optimize the cooler’s efficiency. The cooler is tested and stamped for refrigerant side working pressure of 360 Psi and waterside working pressure of 150 Psi which comply with applicable sections of the ASME standard and in accordance with the European codes ISPESL and TUV. The cooler’s water baffles are fabricated from brass for maximum corrosion resistance and the cooler is provided with water vent and drain connection plugs. The cooler is insulated using 0.75 inch closed cell foam insulation as the standard insulation thickness. Other thicknesses are available as options.
STANDARD FEATURES
Construction
• Galvanized steel C-channel base
• Air-cooled condenser with V-shape allows less installation space requirements
• Easily accessible system component
• Weatherproof with ample space for easy access to power and control panels
• Modular design with multiple compressor execution provides flexibility for varying load conditions and avoids total shut down of the chiller
during service of any of the refrigeration circuits.
• Heavy structure unit with weatherproof, polyerter electrostatic polyerter powder paint, oven baked to ensure maximum gloss and hardness.
• Heavy duty mounting chassis for the whole with weatherproof, polyester powder electrostatic paint, oven-baked to ensure maximum
gloss and hardness.
Refrigeration
• Fully charged unit with R22 refrigerant
• Liquid, discharge and suction pipes are all hard copper pipes which are formed using the CNC highly accurate pipe bending machine to minimize
pipes brazed joints and increase system reliability.
• All exposed copper piping system of the refrigeration circuit are Acra Clad painted after being cleaned.
• Anti-vibration mounts under compressor (Rubber-In-Shear Type).
• Components of each refrigeration circuit include:
- Thermostatic expansion valve
- Liquid line solenoid valve
- Liquid line shut off valve
- Liquid line sight glass
- Disposable filter drier and replacable core filter drier
- High/Low safety pressure switches (capsule type, factory pre-set)
- Charging points with charge nipples
STANDARD FEATURES
Electrical
Weatherproof Electrical Panel: All power and control components including the microprocessor controller shall be assembled inside the electrical panel coated with weatherproof, oven-baked polyester powder electrostatic paint, with IP55 index protection.
Microprocessor controller for full management of the chiller’s operation and safety circuits
Smart lead-lag operation for compressors
Short cycling protection for compressors (time delay)
Freeze protection through water-out probe
Low ambient based on ambient control down to 45°F by cycling fan (ON-OFF).
Control voltage is 220-240V for all components
Control transformer for microprocessor controller
On/Off switch for each compressor Starting contactors for compressors and condenser fan motors
Direct online start
Inherent motor protection for each compressor
Inherent motor protection for each condenser fan motor
General alarm
Control circuit breaker
Pump interlock as protection for whole unit
Control circuit breaker for short circuit protection
Key-Lock and door handle for the electrical panel
Control terminal strip for easy connection with electrical board and easy field installation
Free terminal for remote ON/OFF connection
Free terminal for general alarm output
Power supply monitor (phase failure relay) Single point power connection for electrical panel (refer to electrical data tables)
OPTIONAL FEATURES
Chiller Sound Enhancement Options Sound pressure level There are 3 options to enhance the chiller sound pressure level:
a- Sound jacket kit for compressor
b- Ultra low fan speed 720 rpm/900 rpm (50/60Hz) and compressor with compartment
c- Specially designed fan blades with external rotor motor and compressor with sound jacket kit
Coils Protection Material There are 3 options for coil material:
a- Polyurethane pre-coated aluminum fins with copper tubes
b- Copper fins with copper tubes
c- Polyurethane post-coat copper fins with copper tubes
Galvanized steel wire mesh guard around the chiller’s perimeter
Cooler cladding: Cooler cladding can be aluminum, stainless steel or polyester painted (22 gauge) galvanized steel.
Refrigeration
Other refrigerant application (R407c, R410A)
Heat pump chillers
Cooler tape heater: Factory installed heater to protect cooler from freeze-up at low ambient temperatures down to (-20°F).
Ice storage option: Special chillers are available for this option.
Glycol option: Used for applications requiring water outlet temperature below 40°F.
Suction accumulator Liquid receiver
External pressure relief valve
Pressure gauges (High + Low)
Water flow switch required as a safety interlock to prevent operating the unit without evaporator flow (available for field installation only).
Heat reclaim, heat exchanger for hot water supply (de-super heat exchanger)
None-standard water inlet and water outlet temperature range, which are needed for industrial applications.
Brine application for low working temperature range
Cooler insulation:
Cooler can be insulated with 1.5 inch thick or more closed cell foam insulation.
Chiller Vibration Isolation:
The following options are available for chiller vibration isolation:
- Neoprene Rubber Pads
- 1” Spring isolator
- 2” Seismic Spring Isolators
Electrical
Microprocessor controller with seven day time schedule and/or serial output port
High entering water temperature protection
Automatic or manual pump down.
Low ambient head pressure control by varying the speed of the condenser fan motor using speed controller or frequency inverter
External overload for each compressor
External overload for condenser fan motors
Earth leakage relay for the whole chiller
Ampere meter and/or voltmeter installed on electric panel door
Circuit breaker for each compressor
Circuit breaker for condenser fan motors Unit mounted or non fused disconnect service switch with external handle to isolate unit from power for servicing.
Main power circuit breaker for whole unit Building automation system interface
Petra Water Pumping Unit (PPU)
PETRA Pumping Unit (PPU) includes the hydraulic components necessary for chilled water for use with PSC units. The PPU is designed for easy connection and quick integration into chilled water system equipment by minimizing site labor requirements.
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