Emerson Liebert Challenger ITR - Manual (Page 19)

Air-Cooled System—Standard and Optional Features
11
7.0 A
IR
-C
OOLED
S
YSTEM
—S
TANDARD AND
O
PTIONAL
F
EATURES
7.1 Air-Cooled, Self-Contained Systems—Standard Features
7.1.1 Pump Down Control
The compressor pump-down control is accomplished by a liquid-line solenoid valve used in conjunc-
tion with a low pressure switch.
7.1.2 Condenser
The Liebert manufactured low profile, direct drive propeller fan type air-cooled condenser provides
quiet, efficient operation.
It is constructed of aluminum with a copper tube and aluminum fin coil for corrosion resistance. An
integral, factory wired and tested control panel reduces installation time.
7.1.3 Fan Speed Control
The winter control system features a variable speed motor and a specially designed solid-state fan
speed control transducer.
The transducer senses refrigerant pressure and varies the speed of the fan motor to maintain con-
stant condensing temperature and system capacity. This system permits operation at ambient tem-
peratures as low as -20°F (-29°C).
7.2 Air-Cooled, Self-Contained Systems—Optional Features
7.2.1 Liebert Lee-Temp Winter Control Condenser
The Liebert Lee-Temp winter control system’s heated receivers permit startup and positive head
pressure control at ambient temperatures as low as -30°F (-34.4°C). The Liebert Lee-Temp package
includes insulated receiver, a pressure relief valve, three-way head pressure control valves, and rota-
lock valves (see Figure 5 below).
7.2.2 Quiet-Line Condensers
Quiet-Line Condensers can help your facility meet the strictest noise codes, and do so at less cost than
traditional condensers with acoustical shielding.
Figure 5 Air-cooled condenser with Liebert Lee-Temp
Air-Cooled Condenser
Liebert Lee-Temp
Package (optional)