CLIMAVENETA W3000 compact, Техническое руководство, Страница: 30 / 104

C0240111-04-05-GB
s e t p o i n t
s e t p o i n t
+
P r o p o r t i o n a l b a n d
s t a r t c o m p r e s s o r 1
t [ m i n ]
T i n [ ° C ]
O F F
O N
m a x
m i n
P a s s [ k W ]
B
Figure 5.6 c)
Suppose we have a unit with more than one compressor ( figure 5.7) .
Set point + Banda
proporzionale (100 %)
2x Min
Max
% accensione
2° compressore
Min
% accensione
1° compressore
Potenza
richiesta del
termoregolatore
[%]
Potenza
assorbita
[Kw]
set point
(0%)
Absorbed
power
[K]
%
compressor 1
switch-on
%
compressor 2
switch-on
Set point + prop.
band (100 %)
Thermoregulator power
Request [%]
Figure 5.7: adjustment for a two-compressor unit. Min=theoretical minimum electrical power absorbed by a compressor,
Max=theoretical maximum electrical power absorbed by a compressor.
Let us take a close look at how the compressor is activated ( figure 5.8 ).
The amplitude of zone A coincides with the temperature difference at the evaporator, with all the
compressors running at minimum power.
Zone A is the sum of the zones of each single compressor (A1+A2+…).
When the temperature lies in one of the An zones, the power of the active compressors is modulated
according to system requirements.
When moving from an An zone to the one just above it, the active compressors are taken to minimum
power while waiting for the next one to be switched on. After that, they continue to be modulated in the
new zone.
When moving from an An zone to the one just below it, one of the compressors is switched off while the
others are kept at a minimum.
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