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Cooling regulation is controlled as follows for 2 pipe heating/cooling mode (
M01
=5, 6, 7):
- Operation without half season function (
M15
=0):
The “
COOL
” icon is on to indicate that cooling mode is active.
The regulation logic is as follows:
speed 1
Fan
speed 3
speed 2
ON
OFF
Temp.
Output
Temp.
BCS
(
I08
)
HC
(
I19
)
(
I26
)
(
I27
)
FB
DO5
DO4
DO3
DO1
If the operating temperature rises above
I08
+ (
I19
: 2) relay
DO1
is activated and the fan starts at speed 1 after startup
delay
I36
.
If the temperature continues to rise, the speeds switch as follows:
- speed switches from speed 1 to speed 2 when the temperature rises above
I08
+ (
I19
: 2) + [
I26
x (FB -
I19
)],
- speed switches from speed 2 to speed 3 if the temperature rises above
I08
+ (
I19
: 2) + [
I27
x (FB -
I19
)].
The icon turns on to indicate that cooling mode is active.
If the operating temperature drops to
I08
+ (
I19
: 2) the speed remains constant at speed 1 until the operating tempera-
ture drops below
I08
- (
I19
: 2).
At this point, icon turns off and, depending on the value of parameter
I28,
the fan either stops or continues running:
if
I28
=0 or 3, the fan stops,
if
I28
=1 or 2, the fan stays on at speed 1.
if
I28
=4 or 5, the fan stays on at speed selected manually.
Speed 1 is activated and deactivated together with the cooling output.
The hysteresis of speeds 2 and 3 is calculated automatically at 20% of the FB band (see
“3 speed on-off motor speed
control logic with on/off outputs” page 29
).
Example: if
I18
=0.5°C, FB=2°C, the hysteresis of speeds 2 and 3 is 0.4°C.
N.B.: parameter
I25
is not used.
