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COMMISSIONING AND MAINTENANCE
PWM input signal
With a low input value (<5 % PWM), the pump cannot start. The
pump stops when input signal is 5 to 8% of PWM signal or when
PWM signal is not present, for safety reasons. If the pump re-
ceives no input, due for instance to failure of the signal cable, it
will stop in order to avoid solar system overheating.
Speed (%)
100
0 5 10
20
Electronic circuit
PWM output
Reference
signal
PWM input
Technical specifications
Maximum power
PWM input frequency
Consumption in stand-by
High voltage level of input
signal
Low voltage level of input
signal
Input signal current
Input Duty cycle
30
40
50
60
70
80
PWM input signal (%)
Opto-isolator
Symbol
f
100-4000 Hz
UiH
UiL
IiH
PWM
14 SYSTEM FLUSHING
Before filling the system with mixture of water and glycol, it is
necessary to flush the pipes of the solar system to eliminate all
residues of fluid or scale.
Proceed as follows.
− Verify the flow-meter (C) is completely open
− Turn handle on valve (VR) clockwise
− Open taps (A) and (B) on the return tube
− Flush water in through the cock (B) and wait for it to
come out of the cock (A)
− Allow water to come out for at least 30 seconds
− Turn handle on valve (VR) counter clockwise
− Close taps (A) and (B).
9
During system flushing, pay attention to water coming out
of the taps as vapour could be released with risk of burns or
scalds. Use suitable personal protective equipment.
90 100
single direction
valve function)
Value
< 1 W
4-24 V
< 1 V
< 10 mA
0-100%
9
COMMISSIONING AND MAINTENANCE
Position of the knob
of the return valve VR
Flow
stopped
0°
Flow in
R
(non-return
RC
VR
A
90°
B
Commissioning and maintenance
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