Liebert 50 & 60Hz, 8 Tons user manual 2.8Optional Equipment Piping, 2.8.1Free-CoolingCoil GLYCOOL

Site Preparation and Installation

2.8Optional Equipment Piping

2.8.1Free-Cooling Coil (GLYCOOL)

The free-cooling coil is a secondary coil located upstream of the DX coil. To take maximum advantage of available free-cooling, the secondary coil may operate at the same time as the DX coil. A tempera- ture sensor is factory-mounted to the free-cooling piping. When fluid temperature is sufficiently below the room temperature, cooling is provided by circulating the fluid through the secondary cooling coil (flow is controlled by a motorized valve). Compressors are staged on if needed to supplement the free- cooling. To keep deposits from building up in the free-cooling coil, the coil is flushed periodically.

NOTE

If the free-cooling coil is piped to an open water tower, a CU/NI (cupro-nickel) type coil must be ordered to prevent corrosion of the copper tubes; or a heat exchanger must separate the tower water from the free-cooling loop.

On water-cooled systems, the free-cooling coil outlet can be field piped to the condensing unit inlet, provided a 3-way regulating valve has been installed within the water/glycol condensing unit (see Figure 21).

Figure 21 Optional free cooling coil (3-way valve) on water/glycol units

SL-11088Pg12

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