8
Centrifugal Chillers
D-EIMWC00804-14EN
Introduction
General Description
Daikin Centrifugal Water Chillers are complete, self-contained, automatically controlled fluid
chilling units. Each unit is completely assembled and factory tested before shipment. Models
DWSC/DWDC/DWCC are cooling-only and Models DHSC are cooling with heat recovery
accomplished in a bundle of condenser tubes separate from the cooling tower tube bundle.
In the DWSC and DHSC series, each unit has one compressor connected to a condenser and
evaporator. The DWDC series is equipped with two compressors operating in parallel on a single
evaporator and condenser. The DWCC series is equipped with two compressors, each operating
on one refrigerant circuit of a two circuit evaporator and condenser. Information in this manual
referring to DWSC and DWDC also applies to DWCC and DHSC units except where specifically
noted.
The chillers use refrigerant R-134a to reduce the size and weight of the package compared to
negative pressure refrigerants, and since R-134a operates at a positive pressure over the entire
operation range, no purge system is required.
The controls are pre-wired, adjusted and tested. Only normal field connections such as piping,
electrical and interlocks, etc. are required, thereby simplifying installation and increasing
reliability. Most necessary equipment protection and operating controls are factory installed in
the control panel.
The basic sizes of units are the 050 063, 076, 079, 087, 100, 113 and 126. They provide a cooling
capacity range from 80 tons to 2500 tons. In this manual all references to the DWSC models will
equally apply to other models unless specifically referenced otherwise.
Application
The procedures presented in this manual apply to the standard DWSC/DWDC/DWCC family of
chillers and DHSC heat recovery chillers. Refer to the Operating Manual, OM CentrifMicro II
(latest version available on www.daikineurope.com), for details on operation of the MicroTech
II
unit controller.
All Daikin centrifugal chillers are factory tested prior to shipment and must be initially started at
the job site by a factory trained Daikin service technician. Failure to follow this startup procedure
can affect the equipment warranty.
The standard limited warranty on this equipment covers parts that prove defective in material or
workmanship. Specific details of this warranty can be found in the warranty statement furnished
with the equipment.
Cooling towers used with Daikin centrifugal chillers are normally selected for maximum
condenser inlet water temperatures between 75°F and 90°F (24°C and 32°C). Lower entering
water temperatures are desirable from the standpoint of energy reduction, but a minimum does
existHeat recovery models, DHSC, basically operate the same as cooling-only units. The heat
recovery function is controlled externally to the chiller as explained later in this manual.
Nomenclature
D W D C 063
W = Water-cooled
H = Heat Recovery
D = Dual Compressor
S = Single Compressor
C = Dual, Counterflow
Centrifugal Compressor
Chiller Model, Based on
Impeller Diameter
D = Daikin
