8. Control functions
8.1 Operating panel for ALPHA SOLAR
TM077016
User interface with one button and five LEDs
On the operating panel there is one button and five LEDs which
show the following:
•
Control mode
•
Alarm status.
8.1.1 Alarm or warning
If the pump has detected one or more alarms or warnings, the first
LED switches from green to red. When the fault has been resolved
the operating panel switches back to operating status.
The LEDs indicate the actual operating status or alarm status. This
pump is either for internal control with constant-curve control or
external PWM-signal control with profile C.
Related information
8.2 Control modes
8.2.1 Constant curve or constant speed, I, II or III
At constant-curve operation, the pump runs at a constant curve.
The pump performance follows the selected performance curve, I, II
or III. See the figure below where curve II has been selected.
Q
H
TM068822
Constant-curve/-speed curve
The selection of the constant-curve setting depends on the
characteristics of the solar system in question.
8.3 Control signal
The pump can be controlled via a digital low-voltage pulse-width
modulation (PWM) signal.
The square-wave PWM signal is designed for a 100 to 4,000 Hz
frequency range. The PWM signal is used to select the speed
(speed command) and as feedback signal. The PWM frequency on
the feedback signal is fixed at 75 Hz in the pump.
Duty cycle
d % = 100 x t/T
Example
Rating
T = 2 ms (500 Hz)
U
IH
= 4-24 V
t = 0.6 ms
U
IL
≤ 1 V
d % = 100 x 0.6 / 2 = 30 %
I
IH
≤ 10 mA (depending on U
IH
)
Example
T
t
U
IH
U
IL
TM04991
1
PWM signal
Abbreviation
Description
T
Period of time [sec.]
d
Duty cycle [t/T]
U
IH
High-level input voltage
U
IL
Low-level input voltage
I
IH
High-level input current
Related information
9.1 Connection of the PWM input signal
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English (GB)
