18
A
B
1-27
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
Head available to the system.
Key:
A+B = Head available with by-pass excluded (closed) in Auto mode
B = Head available with by-pass inserted (open) in Auto mode
H
ea
d (m H
2
O)
Flow rate (l/h)
H
ea
d (kP
a)
A
B
1.24 CIRCULATION PUMP.
The boilers are supplied with a built-in circulation
pump with variable speed. When the boiler is in
heating phase the speed of the pump is defined
according to the “P57” in the configuration
menu (Parag. 3.8), in sanitary phase the pump
functions at maximum speed.
In heating phase the Auto and Fixed mode
operations are available.
•
Auto:
automatic pump speed.
In this mode it
is possible to choose between the options at
“Proportional prevalence” and “∆T constant”.
-
Proportional prevalence (∆T = 0):
the pump
speed varies based on the power supplied by
the burner, greater the power, greater the
speed. Moreover, inside the parameter it is
possible to regulate the operation range of
the pump by setting the maximum speed
(adjustable from 100 %
÷
55 %) and the
minimum speed (adjustable from 55 % to
the max set speed).
-
∆T Constant (∆T = 5 ÷ 25 K):
at variable
pump speed to keep the ∆T constant between
system flow and return depending on the set
value of K. Moreover, inside the parameter
it is possible to regulate the operation range
of the pump by setting the maximum speed
(adjustable from 100 %
÷
55 %) and the
minimum speed (adjustable from 54 % to
the max set speed).
•
Fixed (100 % ÷ 55 %):
in this mode the pump
operates at a constant speed, the range of work
is defined between the minimum (55 %) and
the maximum (100 %).
N.B.:
for the boiler to work properly, it is not
allowed to drop below the minimum value
indicated above.
Pump release.
If, after a prolonged period of
inactivity, the circulation pump is blocked,
unscrew the front cap and turn the motor shaft
using a screwdriver. Take great care during this
operation to avoid damage to the motor.
By-pass Regulation (part. 25 Fig. 1-28).
The
boiler is supplied with by-pass closed by 1.5 turns
with respect to all open.
If necessary, the by-pass can be regulated to
system requirements from minimum (by-pass
closed) to maximum (by-pass open). Adjust
using a flat head screwdriver, turn clockwise
and open the by-pass, anticlockwise it is closed.
MA
X.
MIN.
