Lennox CLIMATIC II, User Manual

Page: 17 / 94

V2.2 -00
16
FREE-COOLING
Function
To ensure refrigeration whilst optimising the use of free-cooling, thus limiting electrical consumption to a
minimum.
Description
F F
Free-cooling outline diagram
TEEGFC
ó
Temperature of chilled water input to free-cooling (°C)
TEEG
ó
Temperature of chilled water input to the evaporator (°C)
TSEG
ó
Chilled water output temperature (°C)
TEA
ó
Outside air temperature (°C)
V3VFC
ó
Three-way free-cooling valve
F F
Control of the three-way free-cooling valve:
V3VFC is fed if all the following conditions are satisfied :
ð
TEEGFC is greater than the regulation instruction CONSREG.
ð
TEA<TEEGFC-2°C.
ð
The chilled water circulation pump has been in operation for at least 30 seconds.
ð
The three way valve has remained off for 3 minutes.
ð
The free-cooling water input sensor is not defective.
V3VFC is kept connected as long as all following conditions are satisfied :
ð
TEEGFC is not less than CONSREG.
ð
TEA<TEEGFC.
ð
The pump is in operation.
ð
The free-cooling water input sensor is not defective.
F F
Control of free-cooling fans
The number of ventilation stages required for the batteries is determined by the free-cooling thermostat
THERFC. This parameter depends on the temperature of the water input to the evaporator TEEG and on the
regulation instruction.
V3VFC
free-cooling fan
TEEG
TSEG
TEEGFC
free-cooling unit
evaporator
TEA