Air Cooled Water Chiller with Variable Speed Screw Compressor

As a leading engineering institution in air conditioning high-quality products, Petra is proud to introduce its revolutionary design for its new line of Variable Speed Drive Chillers to meet not only the current but also future requirements of efficiency, reliability, and sustainability

Petra chilled water equipment established its place in the market, as a highly efficient ultra-low sound AHRI / Eurovent certified system. And now with global concern regarding energy and premium efficient products, Petra is introducing its new variable speed drive chiller series with screw compressors, specially designed to reduce energy consumption at part load with superior efficiency

APSG VFD Screw chillers are the ultimate solution for commercial and industrial applications with high-efficiency part-load performance and Ozone friendly refrigerants

Petra`s VFD-controlled compressor series is AHRI / Eurovent certified and by the latest ASHRAE 90.1 standards in terms of efficiency and part-load performance. Petra`s superior efficiency at part load can reach up to an IPLV value of 5.85 (kW/kW) in the high-efficiency versions

As a leading engineering institution in air conditioning high-quality products, Petra is proud to introduce its revolutionary design for its new line of VFD Screw chillers to meet not only the current but also the future requirements of efficiency reliability, and sustainability.

Petra chilled water systems have stabilized their distinguished place in engineering industries, as a high efficient ultra-low sound AHRI certified equipment. And now with all global concerns about energy and questions about the premium efficiency products, Petra decided to proceed with its leading industrial role by obtaining the new variable speed screw chiller, specially designed to reduce your energy consumption and to make your comfort level higher.

APS VFD Screw chiller is the ultimate solution for commercial and industrial applications with the requirements of Confidence, sustainability, and first of all the highest efficiency part-load performance.

Standard Features

-Welded structural C-channel base painted with mono component catalyzed primer sprayed paint

-The base is equipped with welded brackets for heavy-duty lifting lugs

-Structural members are made from gauge 15 [1.8 mm (0.07 inch)] tubular cross members that are semi-welded with stainless steel fasteners. All members & panels (side & roof) are painted with oven-baked polyester electrostatic powder paint

-Suction gas-cooled semi-hermetic twin-screw compressor with variable frequency drives integrated with advanced control system allows the chillers to match actual load conditions, delivering exceptional part-load performance

-Condenser coils are highly efficient microchannel type (MCHE) designed to deliver their duties with optimum performance for all design conditions which reduce the refrigerant charge, and the unit weight

-All coils are air pressure tested by dry air up to 2,900 kPa (420 Psi) underwater. They also undergo dry cleaning after manufacturing for optimum system cleanness

-Condenser coils are covered with protective panels, to ensure uniform air distribution across the coil face area & provide additional protection for the coil from weather elements

-Condenser fans of the external rotor type with many attractive features such as space-saving, compact design, optimum cooling, full speed controllability, and low starting currents

-High-efficiency direct expansion (DX) shell and tube type coolers with inner grooved tubes to optimize the cooler’s efficiency

-Coolers are tested and stamped for a refrigerant side design pressure of 1,000 kPa (145 Psi) and a maximum water side working pressure of 1,500 kPa (220 Psi)

-Independent refrigeration circuit per compressor

-Liquid, discharge, and suction pipes are all hard copper pipes. They are formed using automated CNC pipe bending machines to minimize pipe-brazed joints which in turn increases system reliability

-Epoxy Paint for all exposed copper piping systems of the refrigeration circuit

-Components of each refrigeration circuit include liquid line solenoid valve, liquid line shut off valve, liquid line moisture indicator sight glass, high safety pressure switch, and replaceable core type filter

-Unit is fully charged unit with R-1234ze refrigerant

-Electronic expansion valve: Electronically Operated Step Motor flow control valves, intended for the precise control of liquid refrigerant flow. Synchronized signals to the motor provide discrete angular movement, which translates into precise linear positioning of the valve piston. Easily interfaced with microprocessor-based controllers

-Compressor electronic current monitor and overload protection through the controller

-Free terminal for remote ON/OFF connection

-Free terminal for general alarm output

-Control voltage is 220-240V for all components

-Single point power connection for each electrical panel

-Circuit breaker for each compressor

-Starting contactors for compressors and condenser fan motors

-ON/OFF switch for each compressor

-Control circuit breaker for short circuit protection

-Short cycling protection for compressors (time delay)

-Control transformer mounted & wired that shall supply all unit control voltage from main unit power supply to internal components such as (not limited to) solenoid valves, compressor motor protector, compressor crankcase heater, and microprocessor controller

-Microprocessor controller for full management of chiller operation and safety circuits

-Power supply monitor (phase failure relay) used to protect the power circuit against over or under voltage conditions and against phase loss or loss reversing conditions

-NEMA 3X with IP54 minimum enclosure standard electrical panel. Two separate panels, one for power & the other for control

-Separate electrical box for condenser fan motors located on the condenser side