Carrier 30GTN Product Data

Also see for 30GTN: Service and troubleshooting guide Installation instructions Installation instructions

Contents

Carrier 30GTN Product Data Manual pdf 18 page image

18Application dataMINIMUM COOLER FLUID FLOW RATESAND MINIMUM LOOP VOLUMELeveling unitUnit must be level within 1 /8-in. per ft when installed toensure proper oil return to the compressors.While most outdoor locations are suitable for 30GTN,GTR,GBN,GBR units, the roof is a common site that presents aproblem if roof has been pitched to aid in water removal. Toassure proper oil return, be sure that unit is level, particularlyin its major lengthwise dimension, as compressor oil returnpiping runs in that direction.It should be determined prior to installation if any specialtreatment is required to assure a level installation.Cooler fluid temperature1. Maximum leaving chilled fluid temperature (LCWT) forunit is 70 F (21 C). Unit can start and pull down with upto 95 F (35 C) entering-fluid temperature due to MOP(maximum operating pressure) feature of the TXV. Forsustained operation, it is recommended that entering-fluidtemperature not exceed 85 F (29.4 C).2. Minimum LCWT for standard unit is 40 F (3.3 C). It ispermissible to use a standard microprocessor-controlledComfortLink™ chiller with leaving-fluid temperatures inthe range of 34 to 39.9 F (1° to 3.28 C) only if aprotective brine solution (20% antifreeze solution, orgreater) is used. (See Controls and Troubleshootingliterature for further information.)Medium temperature brine applicationApplication of chiller for brine duty within the 39.9 to 15 F(3.3 to –9.4 C) range is possible by ordering the properfactory-installed brine option. For ratings below 38° F (3.3C) LCWT, contact your local Carrier representative.Leaving-fluid temperature resetReset reduces compressor power usage at part load whendesign LCWT is not necessary. Humidity control should beconsidered since higher coil temperatures resulting fromreset will reduce latent heat capacity. Three reset options areoffered, based on the following:Return-fluid temperature — Increases LCWT temperatureset point as return (or entering) fluid temperature decreases(indicating load decrease). Option may be used in anyapplication where return fluid provides accurate loadindication. Limitation of return fluid reset is that LCWT mayonly be reset to value of design return fluid temperature.Outdoor-air temperature — Increases LCWT as outdoorambient temperature decreases (indicating load decrease).This reset should be applied only where outdoor ambienttemperature is an accurate indication of load. An accessorythermistor is required.Space temperature — Increases LCWT as spacetemperature decreases (indicating load decrease). This resetshould be applied only where space temperature is anaccurate indication of load. An accessory thermistor isrequired.For details on applying a reset option, refer to unitControls and Troubleshooting literature. Obtain orderingpart numbers for reset option from current price pages orcontact your local Carrier representative.Cooler flow rangeRatings and performance data in this publication are fora cooling temperature rise of 10° F (6° C), and aresuitable for a range from 5 to 20 F (2.8 to 11.1 C)temperature rise without adjustment. The ComfortLinkchillers may be operated using a different temperaturerange, provided flow limits are not exceeded. Forminimum flow rates, see Minimum Cooler Fluid FlowRates and Minimum Loop Volume table. High flow rateis limited by pressure drop that can be tolerated. Ifanother temperature range is used, apply LCWTcorrection as given in Selection Procedure example onpage 53.APPLICATION V NNormal Air Conditioning 3 3.25Process Type Cooling 6 to 10 6.5 to 10.8Low Ambient Unit Operation 6 to 10 6.5 to 10.8NOTES:1. Minimum flow based on 1.0 fps (0.30 m/s) velocity in cooler without specialcooler baffling.2. Minimum Loop Volumes:Gallons = V x ARI Cap. in tonsLiters = N x ARI Cap. in kWMINIMUM COOLERFLOW RATEMINIMUM LOOPVOLUMEUNIT SIZE30GTN,GTR,GBN,GBRGpm L/s Gal L050 37.7 2.38 153 580060 47.5 3.00 181 684070 47.5 3.00 210 796080 66.7 4.20 243 920090 59.5 3.75 272 1029100 84.1 5.30 301 1138110 81.1 5.30 333 1260150, 300A/B 192.0 6.90 502 1900175, 350A/B 192.0 6.90 568 2150200, 400A/B 192.0 6.90 635 2403