Introduction
1
1.0 INTRODUCTION

1.1 System Descriptions

Liebert Challenger ITR environmental control systems are available in three main system configu-
rations:
• self contained system with a scroll compressor in the room unit
• self contained chilled water system
• split system with an evaporator section and a remote condensing unit
All three types are available in horizontal flow configurations. Each model requires three-phase
power. Units are available in 208, 230, 460, or 575 V, 60 Hz; and 200, 230 or 380/415 V, 50 Hz.
The following features are included as standard in all room units regardless of the type of system:
V-frame coil, infrared humidifier, finned tubular stainless steel electric reheat, 2" filter, individual
high voltage fused protection, and fan assembly.
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, is listed below. Check model numbers to see what is supplied with your unit.
1.1.1 Self Contained Systems
Air-Cooled Models
Complete refrigeration system including hot gas bypass and crankcase heater with standard con-
denser and fan speed control for 95°F (35°C) ambient at sea level.
Water-Cooled Models
Compete refrigeration system including hot gas bypass with water/glycol-cooled condenser and two-
way water regulating valve with bypass.
Glycol-Cooled Models
The water-cooled model as described above plus pump package and 95°F (35°C) design ambient dry-
cooler.
GLYCOOL Models
Complete refrigeration system including hot gas bypass with glycol condenser and three-way water reg-
ulating valve plus an integrally piped Econ-O-Coil with three-way modulating control valve.
1.1.2 Chilled Water Models
Chilled Water models include chilled water piping, three-way modulating valve and actuator assembly.
1.1.3 Split Systems
Each Air-Cooled split system consists of an evaporator section and one of the following condensing units.
Prop Fan
Includes scroll compressor, condenser coil, prop fan, high pressure switch, and Lee-Temp head pres-
sure control. Unit is designed for outdoor location.
Centrifugal Fan
Includes scroll compressor, condenser coil, centrifugal blower assembly, high pressure switch, head
pressure control valve, Lee-Temp receiver and liquid line solenoid valve. Unit must be mounted
indoors. Duct flanges are optional.
Water/Glycol Condensing Units
Each water-cooled split system consists of an evaporator section and a water/glycol condensing unit,
which includes scroll compressor, coaxial condenser, water regulating valve, and high pressure switch.
Design pressure is 150 psi (1034 kPa) as standard and 350 psi (2413 kPa) as optional.
Each glycol-cooled split system consists of an evaporator section, a water/glycol condensing unit (as
described above), a pump package and a 95°F (35°C) design ambient drycooler.