Emerson Liebert Challenger ITR - Manual (Page 18)

Refrigeration Systems
10
6.0 R
EFRIGERATION
S
YSTEMS
Two versions are available:
• Self-Contained Systems
• Split Systems
6.1 Self-Contained Systems
These systems feature a scroll compressor and controls, expansion valve, hot gas bypass and evapora-
tor coil in the room unit.
Air-Cooled models also include a crankcase heater on the compressor and require field connection to
remote air-cooled condenser.
Water, Glycol and GLYCOOL models also include a coaxial condenser with field connections
required to the water or glycol coolant loop.
Water/Glycol models have two-way WRV with bypass.
GLYCOOL models have three-way WRV.
6.2 Split Systems
These systems feature the evaporator coil and expansion valve in the room unit, with the scroll com-
pressor, and the condensing equipment located in one of several different types of pre-charged con-
densing units.
6.3 Refrigeration System Components—Standard Features
6.3.1 Compressor
The heart of the refrigeration system is the compressor.
All self-contained evaporator units and split system condensing units contain a high efficiency, quiet
operating scroll compressor. The compressors have internal vibration isolating mountings, pressure
safety controls and built-in overload protection.
6.3.2 Evaporator Coil
The evaporator coil is designed for the high sensible heat ratio required by electronic equipment
applications. The copper tube, aluminum fin coils are configured in a V-frame for smooth air flow
through the unit.
6.3.3 Safety Control
Every Liebert Challenger compressor has a high-pressure switch with an exclusive manual reset after
high pressure cut-out. This prevents cycling the compressor at high pressure, resulting in greater effi-
ciency and longer compressor life.
6.3.4 Expansion Valve
The externally equalized thermostatic expansion valve smoothly controls the flow of refrigerant
through the coil and provides precise control of superheat.