Liebert® Challenger™ 3000 with Liebert iCOM® - Emerson Network ...

GLYCOOL Systems—Standard and Optional Features7.0 GLYCOOL SYSTEMS—STANDARD AND OPTIONAL FEATURESThe Liebert GLYCOOL free-cooling system is integrated with a glycol-cooled LiebertChallenger 3000.The GLYCOOL system is a normal glycol system with the addition of a second cooling coil in the airhandling unit and a three-way valve. During colder months, the glycol solution returning from theoutdoor drycooler is routed to the second coil, and becomes the primary source of cooling for the room.At drycooler fluid temperatures, about 8°F (4.4°C) below room return temperature, cooling begins inthe second coil. As fluid temperatures drop, compressor operation stops, and the total cooling needs ofthe room are maintained by the second coil (Econ-O-Coil).The GLYCOOL system contains all the standard features of a glycol-cooled system plus the following.7.1 GLYCOOL Self-Contained Systems—Standard Features7.1.1 Comparative Temperature MonitorA solid-state temperature monitor compares the room air temperature and entering glycoltemperature. When air temperature is higher than glycol temperature, the monitor communicates tothe Liebert iCOM that “free-cooling” is available.7.1.2 GLYCOOL CoilThe GLYCOOL coil is strategically located in the return air stream of the environmental controlsystem. This coil is designed for closed-loop applications using properly treated glycol solutions.The air is first filtered before entering the coil and then is either precooled or totally cooled beforeentering the refrigeration coil. The glycol flow to the coil is controlled by a pre-piped modulatingthree-way valve. When supplied with a sufficiently cooled glycol solution, the coil provides the samecooling capacity as is obtained during the refrigeration cycle of the compressor.7.1.3 GLYCOOL Three-Way Control ValveThe GLYCOOL Three-Way Control Valve opens full anytime the temperature of the glycol solution isbelow room temperature, to take full advantage of all possible free-cooling. As the outdoor ambientdrops, the three-way control valve modulates the flow to the GLYCOOL coil. It maintains constanttemperature in the room and includes operating linkage and electronic motor. Unlike other valves ofthis nature, there is no over travel linkage or end switches to be adjusted. Standard design pressure is150psi (1034kPa).7.1.4 Glycol-Regulating ValveA head pressure operated three-way glycol regulating valve accurately controls the condensingtemperature and system capacity for various entering glycol temperatures. The valve has three-wayaction.15