Quantech QTC4 STYLE A Series Installation Operation & Maintenance

Also see for QTC4 STYLE A Series: Installation operation & maintenance

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Quantech QTC4 STYLE A Series Installation Operation & Maintenance Manual pdf 17 page image

SECTION 2 - PRODUCT DESCRIPTIONQUANTECH17FORM QTC4-NM1ISSUE DATE: 4/2/20182SEMI-HERMETIC QUANTECH TWIN-SCREWCOMPRESSORSCompressors are direct drive, semi-hermetic, rotarytwin-screw type, including: muffler, temperature actu-ated ‘off-cycle’ heater, IP55 terminal board and preci-sion machined cast iron housing.Reliable suction gas cooled, high efficiency,accessible hermetic compressor motor, full suction gasflow through mesh screen filter, with inherent internalthermal overload protection and external current over-load on all three phases.Continuous function, microprocessor controlled,Variable Speed Drive (VSD) shall provide valve-less,smooth capacity control from 100% down to 10% ofchiller capacity.In addition, elimination of the slide valve and asso-ciated unloading components has resulted in a 50%reduction in compressor moving parts.EVAPORATORThe evaporator is a shell and tube, hybrid falling filmtype heat exchanger. It contains a balance of floodedand falling film technology to optimize efficiency, min-imize refrigerant charge, and maintain reliable control.A specifically designed distribution system providesuniform refrigerant flow for optimum performance.CONDENSERThe QTC4 introduces micro-channel coil to theQuantech screw compressor chiller line. The micro-channel maximizes condenser heat transfer, resultingin a smaller footprint, and reduces refrigerant chargeby as much as 50%.Each condenser coil is a single piece all aluminumconstruction including headers, tubes and fins to avoidgalvanic corrosion due to dissimilar metals. Coils andheaders are brazed as one piece. Integral sub-coolingis included. The design working pressure is 375 PSIG(25.9 barg).Multiple, standard low sound, high efficiency, TEAOmotor driven fans move air through the coils. They aredynamically and statically balanced, direct drive withcorrosion-resistant glass fiber reinforced compositeblades molded into low-noise, full airfoil cross sec-tions, providing vertical air discharge from extendedorifices for efficiency and low sound.Fan motors are Totally Enclosed Air-Over (TEAO),squirrel-cage type and current protected. The directdrive motors feature double-sealed and permanentlylubricated ball bearings, cutting down on maintenancecost over the life of the unit.REFRIGERANT CIRCUITAn independent refrigerant circuit is provided percompressor. Each circuit uses copper refrigerant pipeformed on computer controlled bending machines toreduce the number of brazed joints resulting in a reli-able and leak resistant system.• Discharge lines are provided with a manual com-pressor shutoff service valve (See Accessoriesand Options on Page 19 for suction line servicevalve).• The external oil separators, with no moving partsand designed for minimum oil carry-over, aremounted in the discharge line of the compressor.• Liquid line components include: high absorp-tion removable core filter-drier, sight glasses withmoisture indicators, manual shut-off valve withcharging port, orifice and electronic expansionvalve.• An economizer (flash) tank is located in each re-frigerant circuit to increase the system efficiency.ELECTRICALQuantech has years of experience designing VariableSpeed Drives (VSDs) specifically for chiller applica-tions. The result is an extremely reliable air-cooledchiller system that offers industry leading efficiency atreal world operating conditions, valve-less compres-sor loading/unloading, excellent capacity control, highpower factor and soft start.Incoming single point power is standard utilizing alockable circuit breaker, 115VAC control transformer,VSD, fan contactors, ON/OFF unit switch, microcom-puter keypad and display, Chiller Control and VSDLogic boards, and relay boards.Standard design includes IP55 rating, powder paintedsteel cabinet with hinged, latched, and gasket sealedouter doors equipped with wind struts for safer servic-ing. The panel includes a control display access door sothat display and control features can be accessed with-out opening main cabinet doors. All exposed powerwiring is routed through liquid-tight, UV-stabilized,non-metallic conduit.