Selection Procedure

The Series R ^® chiller performance is rated in accordance with ARI Standard 550 Certification Program. Chiller selections and performance information can be obtained through the use of the Series R chiller selection program available through local Trane sales offices.

Performance

The Series R computer selection program provides performance data for each chiller selection at the full load design point and part load operating points as required.

It should be noted that changing the number of water passes or the water flow rates may significantly alter the performance of a particular chiller. To obtain the maximum benefit from the wide range of selections available, designers are encouraged to develop performance specifications and use the computer selection program outputs to optimize their selections. This will allow the selection of the particular compressor-evaporator-condenser combination which most closely meets the job requirements. All selections should be made using the computer selection program.

Fouling Factors

ARI Standard 550 includes a definition of clean tube fouling. Recommended field fouling allowances have not changed on a relative basis; the standard fouling adjustment is a 0.00025 increment from 0.0000 "clean."

Chiller specifications should be developed using the most current standard fouling factors.

Unit Performance with Fluid Media Other Than Water

Series R chillers can be selected with a wide variety of media other than water. Typically used media include ethylene glycol or propylene glycol either in the evaporator, condenser or both. Chillers using media other than water are excluded from the ARI 550 Certification Program, but are rated in accordance with ARI Standard 550. Trane factory performance tests are only performed with water as the cooling and heat rejection medium. For media other than water, contact the local Trane sales office for chiller selections and information regarding factory performance testing.

Dimensional Drawings

The dimensional drawings illustrate overall measurements of the unit. The service clearances indicate clearances required to easily service the recommended Series R chiller.

All catalog dimensional drawings are subject to change. Current submittal drawings should be referred to for detailed dimensional information. Contact the local Trane sales office for submittal information.

Electrical Data Tables

Compressor motor electrical data is shown in the data section for each compressor size. Rated load amperes (RLA), locked rotor wye amperes (LRAY) and locked rotor delta amperes (LRAD) for standard voltages of all 50 and 60 Hertz, 3 phase motors are shown. The RLA is based on the performance of the motor developing full rated horsepower. The kW rating of the motor will equal or exceed the kW requirement determined by the Series R computer selection program at design conditions. If motor kW draw at design conditions is less than the kW rating of the motor, the RLA at design conditions is determined by multiplying the motor RLA (at the desired voltage) by the ratio of design kW to the motor kW rating. This is done by the Series R chiller computer selection program. RLA is available in the selection program as part of the design predictions. Predicted values include power factor variation from point to point.

A voltage utilization range is tabulated for each voltage listed. Series R chillers are designed to operate satisfactorily over a utilization range of ± 10 percent of the standard design voltages of 200 V, 230 V, 380 V, 460 V, and 575 V for 60 Hertz, 3 phase and 380 V, 400 V, 415 V for 50 Hertz, 3 phase.

Evaporator and Condenser Pressure Drop

Pressure drop data is determined by the Series R chiller computer selection program available through local Trane sales offices.

Part Load Performance

The Series R chiller possesses excellent part load performance characteristics. Actual air conditioning system loads are usually significantly less than full load design conditions. Therefore, the chillers may operate at full load relatively little percentage of the time. The Series R chiller can provide significant operating savings at these part load conditions due to its energy efficient operation.

Part load chiller operation is normally associated with reduced condenser water temperatures. At part load operation, the heat rejected to the cooling tower is less than at full load operation. Also, part load operation is typically associated with reduced outside wet bulb temperatures, resulting in improved cooling tower performance. The net result of less heat rejection and lower wet bulb temperature is cooler condenser water entering the chiller and improved unit performance. To determine specific unit part load performance, use the Series R chiller computer selection program.