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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. |
