Trane RTHD manual Selection Procedure, Unit Performance with Fluid Media OtherThanWater

Selection Procedure

Unit Performance with Fluid Media OtherThanWater

Series R chillers can be provided with a wide variety of fluid media other than water, including ethylene glycol and propylene glycol— in the evaporator, condenser or both. Chillers using media other than water are excluded from the ARI 550/590-2003 Certification Program, but are rated in accordance with ARI Standard 550/590-2003.Trane factory performance tests are only performed with water as the cooling and heat- rejection media.When considering selection of media other than water, contact the localTrane sales office for chiller selections and factory performance testing information.

Fluid media other than water lowers the heat transfer coefficient, and therefore reduces chiller performance. In general, it is good practice to hold the percent glycol added to within the minimum allowed by theTrane selection program, based on either (a) unit operating temperatures, or

(b)the operating temperatures the evaporator or condenser water will experience under its full range of conditions. Adding more glycol than required for the specific application is equivalent to selecting a less efficient chiller. Lower-viscosity glycols such as ethylene will have less adverse impact on chiller performance than higher- viscosity glycols such as propylene.

Evaporator and Condenser Pressure Drop

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

Dimensional Drawings Dimensional drawings provided for selection purposes illustrate overall measurements of the unit.The recommended service clearances are those required to easily service the Series R chiller.

All catalog dimensional drawings are subject to change, and current submittal drawings should be referenced for more detailed dimensional information. Dimensional drawings are also available from the selection program. Contact the localTrane sales office for submittal information.

Electrical DataTables

Compressor motor electrical data is provided in the data section for each compressor size. Rated load amperes (RLA), locked rotor wye amperes (LRA) and expected inrush for theWye-delta and Solid State Starter configurations are shown.

Although the terms “LRA” and “expected inrush” are often used interchangeably, the distinction applied here is that LRA is the rated inrush for the motor, but expected inrush is that allowed by the starter, based on the specific configuration.

Selecting starters in theWye-delta or Solid State configuration lowers expected inrush vs. the Delta (or “across- the-line”) configuration. A Solid State Starter configuration lowers the expected inrush by approximately 50 percent, whileWye-Delta lowers it by approximately 66 percent.

The RLA is based on the motor’s performance when reaching full rated horsepower.The kW rating of the motor will equal or exceed the kW requirement indicated 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 this ratio: design kW/ motor kW rating.This calculation is performed within the Series R chiller computer selection program, making RLA available 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: (a) 200V, 230V, 380V, 460 V, and 575 V for 60 Hertz, 3- phase, and (b) 380V, 400V,

415 V for 50 Hertz, 3-phase.

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