Emerson Liebert Challenger ITR - Manual (Page 68)

Electrical Data
60
Outdoor Unit
Propeller Fan Drycooler (Standard)
The Liebert manufactured drycooler shall be the low profile, slow speed, direct drive propeller fan
type. The drycooler shall be constructed of aluminum and contain a copper tube aluminum fin coil
with an integral electric control panel. The drycooler shall be designed for _____ °F (°C) ambient.
Centrifugal Fan Drycooler (Optional)
The system shall be supplied with a centrifugal fan drycooler (LCD). The drycooler shall be con-
structed of galvanized steel with a copper tube, aluminum fin coil. The heavy duty fan shall be the
centrifugal type, double width, double inlet. The 1750 RPM (1450 RPM @ 50 Hz) fan motor shall be
mounted on an adjustable base, and equipped with an adjustable motor pulley. A three-way control
valve and thermostat shall maintain the desired fluid temperature. Electrical controls shall be in a
rain-tight enclosure. The system shall be designed for _____ °F (°C) ambient. The drycooler shall have
a _____ Volt, 3 phase, _____ Hz power supply.
Single Glycol Pump Package (Standard)
This system shall be provided with a centrifugal pump mounted in a weatherproof and vented enclo-
sure. The pump shall be rated for _____ GPM (l/s) at _____ ft. of head (kPa), and operate on _____ Volt,
3 phase, _____ Hz.
Dual Glycol Pump Package (Optional)
The dual pump package shall include pumps, enclosure, and field mounted flow switch. The pumps
shall be wired to the drycooler control box which includes a lead/lag switch for the pumps. The
standby pump shall automatically start upon failure of the lead pump. Each pump shall be rated
_____ for GPM (l/s) at _____ feet of head (kPa).
2.2.3 GLYCOOL Self-Contained Systems
Econ-O-Coil
The Econ-O-Coil shall be constructed of copper tubes and aluminum fins and be located upstream of
the evaporator coil. The Econ-O-Coil shall be designed for closed-loop applications using properly
treated glycol solutions. Applications using a cooling tower loop or other open water system must
specify a 70/30 Cu-Ni Econ-O-Coil for improved corrosion resistance. The coil shall be rated at _____
BTU/HR (kW) sensible cooling capacity with a 45°F (7.2°C) entering glycol solution temperature. The
GLYCOOL coil shall require _____ GPM (l/s) and the total unit pressure drop shall not exceed _____
feet of water (kPa) when in the free cooling mode.
Three-way GLYCOOL Valve
The Econ-O-Coil coil shall be equipped with a fully proportional three-way control valve. This motor-
ized control valve shall control the amount of flow to the Econ-O-Coil and maintain constant tempera-
ture and relative humidity.
Glycol Condenser
The glycol system shall be equipped with a coaxial condenser having a total pressure drop of _____
feet of water (kPa) and a flow rate of _____ GPM (l/s), with _____ °F (°C) entering 40% ethylene glycol
temperature.
Three-way Water Regulating Valve
The condenser circuit shall be pre-piped with a head pressure actuated three-way water regulating
valve.
Design Pressure
The Econ-O-Coil/condenser circuit shall be designed for a pressure of [(150 PSI (1034 kPa)) (300 PSI
(2069 kPa))].
Comparator Circuit
The system shall be equipped with a microprocessorcontrolled comparator sensor that permits free-
cooling operation whenever entering glycol temperature is below return-air temperature.