Carel pCO2 Manual

Standard Chiller/HP modulare per compressore a vite con driver CAREL
Cod.: +030221241 Rel. 1.0 dated 25 September 03
35
19 Free Cooling Control
Inputs used
• Water temperature at evaporator outlet
• Water temperature at inlet of Free Cooling battery
• Outside air temperature
Parameters used
• Type of unit
• Number of units
• Type of condensation
• Number of fans
• Free Cooling valve type
• Free Cooling type control
• Integration time
• Control set point
• Control set point offset
• Minimum Free Cooling Delta
• Maximum Free Cooling Delta
• Free Cooling Control differential
• Maximum threshold for Free Cooling valve opening
• Minimum threshold for condensation speed controller
• Free Cooling antifreeze threshold
• Compressor activation delay
Outputs used
• Condensation fans
• Condensation fans speed controller
• Free Cooling ON/OFF valve
• Free Cooling 3-way valve
19.1.1 Description of operation
Free Cooling control makes it possible to exploit the temperature conditions of external air to facilitate cooling use water. To this end, a heat exchanger is
supplied. If necessary, a certain quantity of water is returned to this exchanger by the system, deviated via an appropriately commanded valve.
The favourable conditions of outside air cause the water to cool beforehand, and, therefore activation of the cooling devices is delayed. Free
Cooling is available in the air/water unit in the internal Free Cooling mode only. i.e. with the Free Cooling battery housed inside the machine
near the condensation battery/ies, with which its shares control of the condensation fan/s.
BATTERIA DI CONDENSAZIONE = CONDENSATION BATTERY
BATTERIA DI FREE COOLING = FREE COOLING BATTERY
EVAPORATORE = EVAPORATOR
19.2 Free Cooling activation condition
The entire Free Cooling procedure is based on a relationship between the temperature value measured by the external temperature probe, and the
temperature value measured by the temperature probe located at the input of the Free Cooling heat exchanger and the set Free Cooling delta.
External T. < Free Cooling Input T. – Free Cooling Delta
If this condition occurs, the control manages Free Cooling, enabling /disabling the dedicated devices.

Carel pCO2 Specifications

General

Brand	Carel
Model	pCO2
Category	Controller
Language	English