Lennox CLIMATIC 60 User Manual page 15

COMPONENTS
Control
The CLIMATIC™ 60 adjusts and holds the fl uid outlet temperature as close as possible to the set point, by controlling the number of
compressor stages depending on the thermal load of the system. The controller constantly calculates the required capacity to reach the
temperature set point. This variable is called "CAPACITY FACTOR" (CF) and its value can vary from 0 to 100%. It is directly linked to
the number of control stages of the unit. Thus for a unit with 4 stages of regulation, the CF will start and stop a stage with the following
values: ~0-25-50-75-100%. It then evolves following the principles detailed in the diagram.
Difference between the outlet
water temperature and the
In order to anticipate, the reference point is recalculated each time the difference between air temperature and set point reaches a
minimum or a maximum.
Moreover the inlet temperature is used to limit the capacity factor to prevent from too slow reactivity of outlet capacity factor of the unit.
Example:
• Unit EAC 2104: cooling capacity: 210KW with:
* C1.Cp1 = 19.2%,
* C1.Cp2 = 30.8%,
* C2.Cp1 = 19.2%,
* C2.Cp2 = 30.8%.
• Maximum delta T° (inlet - outlet) at full load: setting (3261) = 5.0°C.
• Outlet water evaporator temperature set point: setting (3238) = (3239) = 7.0°C.
Minimum inlet
Stage
temp. (°C)
0 0
1 8.54
2 10.80
3 11.04
4 12.00
CL60-AC CHILLER-IOM-1011-E
CF FROZEN
set point
CF DECREASES
(removes capacity stages)
FAST
Maximum
capacity factor
(%)
0
30.8
61.6
80.8
100.0
CF INCREASES
(starts more capacity stages)
CF FROZEN
Water temperature
can change
SLOW SLOW
Expression
0
7.0 + 30.8*5.0/100
7.0 + 2*30.8*5.0/100
7.0 + (19.2+2*30.8)*5.0/100
7.0 + 2*(19.2+30.8)*5.0/100
FAST
Compressor Compressor
ON circuit 1
1 2
1 2
1 2
1 2
1 2
ON circuit 2
1 2
1 2
1 2
1 2
1 2
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