Introduction; System Descriptions; Compressorized Systems; Glycool ™ (Chilled Glycol Cooling) Systems - Emerson Liebert Challenger 3000 Operation & Maintenance Manual

1.0 I
NTRODUCTION
1.1

System Descriptions

The Liebert Challenger 3000
in several configurations.
1.1.1

Compressorized Systems

NOTE
Compressorized systems may be a self-contained system, with the compressor in the Liebert
Challenger 3000/Liebert Challenger ITR unit, or a split system, with the compressor in a
separate condensing unit.
These systems may be air, water, or glycol cooled, depending on the heat rejection method selected.
Cooling—One stage standard; variable capacity with digital scroll, optional.
Heating—Two stages of electric reheat standard; SCR controlled electric reheat, hot water reheat,
hot gas reheat on water and glycol cooled systems optional.
Humidification—Infrared standard; steam generating optional.
Dehumidification—Hot gas bypass locked out standard
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1.1.2 GLYCOOL (Chilled Glycol Cooling) Systems
GLYCOOL systems have all of the features of a compressorized water or glycol system, plus a second
cooling coil that is connected into the water circuit. When fluid temperature is sufficiently low (below
room temperature), cooling is provided by circulating the fluid through the second cooling coil (flow is
controlled by a motorized valve.) This is then the primary cooling source, and it greatly reduces the
compressor operation.
Cooling—Modulated cooling valve opens proportionally to match room needs (primary), one or two
stages of mechanical refrigeration (secondary)
Heating—Two stages of electric reheat standard; hot water reheat optional
Humidification—Infrared standard; steam generating optional
Dehumidification—Hot gas bypass locked out standard
1.1.3

Chilled Water Systems

These systems utilize a central chiller and control cooling by modulating a control valve in the chilled
water line.
Cooling—Proportional in response to room needs
Heating—Two stages of electric reheat standard; hot water reheat optional
Humidification—Infrared standard; steam generating optional
Dehumidification—Chilled water valve opens proportionally in response to room needs
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and Liebert Challenger ITR
3
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Precision Cooling systems are available

Introduction