29
21
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
1.27 CIRCULATION PUMP.
The indoor unit is supplied with two circulator
pumps, one for the heat generator and another
for the heat pump mode.
- Circulator pumps run at variable speeds and
operate as follows:
-
Fixed ("A 05" = 0):
The heat circulator pump
speed is fixed and corresponds to parameter
"A 04." The heat generator circulator pump
speed is fixed and corresponds to parameter
"A 19."
Total head available to the system.
Heat generator circuit
Heat pump circuit
A = Head available to the system.
B = Absorbed power by the circulator (dotted area)
-
∆T constant ("A 05" = 5 K):
the heat circula-
tor pump speed varies to maintain ∆T = 5 K
constant between the system flow and return.
It is also possible to adjust the operating
range of the circulator pump by setting the
maximum speed "A 04" and the minimum
speed "A 03." The heat generator circulator
pump speed varies to maintain ∆T = "A 05"
constant between the system flow and return.
Also, you can adjust the pump operating
range, by setting the maximum speed “A 19”
and the minimum speed “A 18”.
H
ea
d (kP
a)
Ci
rcu
la
to
r p
um
p a
bs
or
be
d p
ow
er (
W
)
Flow rate (l/h)
Max. s
peed
Min. s
peed
A
B
H
ea
d (kP
a)
Ci
rcu
la
to
r p
um
p a
bs
or
be
d p
ow
er (
W
)
Flow rate (l/h)
Max. s
peed
Min. s
peed
A
B
Please note: for proper system operation, make
sure that the minimum flow rate never drops
below 500 l/h in operating conditions.
Pump release.
If, after a prolonged period of
inactivity, the circulation pump is blocked, turn
the motor shaft using a screwdriver. Take great
care during this operation to avoid damage to
the motor.
