Introduction; System Descriptions; Compressorized Systems; Glycool™ (Chilled Glycol Cooling) Systems - Liebert CHALLENGER 3000 Operation And Maintenance Manual

1.0 I
NTRODUCTION
1.1

System Descriptions

Challenger 3000
Each configuration can operate with either Advanced Microprocessor Controls (A), or Advanced
Microprocessor Controls with Graphics (G). A brief description of each, including operational differ-
ences, are listed below. Check model numbers to see what is supplied with your unit.
1.1.1

Compressorized Systems

NOTE
Compressorized systems may be a self-contained system – with the compressor in the
Challenger 3000 unit, or a split system – with the compressor in the separate condensing unit.
These systems may be air, water, or glycol cooled, depending on the heat rejection method selected.
Cooling—One stage standard; two stages of mechanical refrigeration with optional split coil.
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; part coil operation optional
1.1.2 GLYCOOL™ (Chilled Glycol Cooling) Systems
GLYCOOL™ systems have all of the features of a compressorized water or glycol system, plus a sec-
ond 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
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
Humidification—Infrared standard; steam generating optional
Dehumidification—Chilled water valve opens proportionally in response to room needs
™
Liebert environmental control systems are available in several configurations.
1

Introduction