15
2.13 Residual head of the circulator
The boiler is equipped with a high efficiency modulating circula
-
tor already connected hydraulically and electrically, the availa-
ble useful performances of which are indicated in the graph. The
modulation is managed by the board through the DUTY CYCLE
PUMP parameter - INSTALLER access level. The circulator is
factory set with a 7 meter head curve.
b
The boiler is equipped with an anti-blocking system that
starts an operating cycle every 24 hours of rest in any ope-
rating state.
a
The “anti-blocking” function is active only if the boiler is
electrically powered.
If there is a need to use a different curve, the desired level can be
selected on the circulator.
b
If you need to “release” the seized rotator shaft, please
see par. 6.1.1.
2.13.1 Variable speed circulator
The modulating circulator function is active only in the heating
function. When switching the three-way to the sanitary, the circu-
lator always works at maximum speed. The modulating circulator
function applies only to the boiler circulator and not to the circu-
lators of any external connected devices (e.g. booster circulator).
Through the DUTY CYCLE PUMP parameter it is possible to cho-
ose between 4 management modes according to the situations
and the type of system.
1 - VARIABLE SPEED CIRCULATOR WITH PROPORTIONAL
MODE (41 <= DUTY CYCLE PUMP <= 100)
In this mode the boiler card determines which flow curve to adopt
according to the instantaneous power delivered by the boiler.
2 - VARIABLE SPEED CIRCULATOR WITH CONSTANT ∆T
MODE (2 <= DUTY CYCLE PUMP <= 40)
In this mode, the installer sets the ∆T value to be maintained
between flow and return (e.g .: by entering a value = 10, the circu
-
lator speed will change to obtain a system flow rate with the aim
of maintaining the ∆T between the upstream and downstream of
the exchanger of 10°C).
3 - CIRCULATOR IN MAXIMUM FIXED SPEED MODE (DUTY
CYCLE PUMP = 1)
In this mode the circulator, when activated, always works at ma-
ximum speed.
Used on systems with high pressure drop where it is necessary
to make the most of the boiler head in order to ensure sufficient
circulation (system flow rate at maximum speed less than 600
liters per hour).
Used in the presence of mix bottles with high flow rates in the
downstream circuit.
Operationally:
- Enter the DUTY CYCLE PUMP parameter
- Set the value = 1
4 - EXCEPTIONAL USE OF A STANDARD NON-SPEED
ADJUSTABLE CIRCULATOR (DUTY CYCLE PUMP = 0)
This mode must be used in exceptional cases in which a traditio-
nal UPS circulator is to be used in the boiler.
CONFIGURATIONS RECOMMENDED BY THE MANUFACTU-
RER
EXTERNAL SENSOR YES
(WEATHER
COMPENSATION)
EXTERNAL SENSOR
(NO WEATHER
COMPENSATION)
LOW
TEMPERATURE
(floor)
ΔT constant
(5 ≤ DUTY CYCLE PUMP ≤ 7)
PROPORTIONAL
(DUTY CYCLE PUMP = 85)
HIGH
TEMPERATURE
(radiators without
thermostatic valves)
ΔT constant
(15 ≤
DUTY CYCLE PUMP
≤ 20)
PROPORTIONAL
(DUTY CYCLE PUMP = 85)
HIGH
TEMPERATURE
(radiators with
thermostatic valves)
ΔT constant
(15 ≤
DUTY CYCLE PUMP
≤ 20)
PROPORTIONAL
(DUTY CYCLE PUMP = 60)
Flow rate (l/h)
Residual head (mbar)
7-metre circulator
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
Pr
eva
le
nz
a
[m
ba
r]
Portata impianto [l/h]
100
85 (default)
60
41
