SI21 Solar Pump VFD Manual
4
equipment. To avoid it, you can set up jumping frequency.
5. As output voltage of the VFD is pulse-wave type, if there is capacity which can improve power factor or
pressure-sensitive resistance which used for thunder-proof in the voltage output side, the frequency VFD will
break off or its parts will be damaged, so it is necessary to dismantle them. Moreover, it is proposed not install
switch parts like air switch and contactor (if it is necessary to install switch on output side, please make sure
the output electricity of frequency VFD is zero when the switch is working)
6. At over 1,000 meters altitude, the VFD’s heat dissipation function worsened due to the thin air, it is necessary
to use less.
7. The VFD output voltage is pulse wave type. If using digital multi-meter measurement, deviation of the reading
will be great. And the deviation is different by using different type of digital multi-meter. Under normal
circumstances, while RMS 380V, digital multi-meter reading is around 450V.
8. Solar panel can be connected in the series or parallel. For rated voltage 380V controller, we suggest working
voltage between 480V and 560V while MPPT. What means the solar panel open circuit voltage should be
between 600V and 700V.
1.4 Technical Specification
Solar pump
VFD
power(kW)
Pump
Max solar
power
input
(kW)
Max DC
input
voltage V
Recommend
Voc voltage
(V)
Rated
output
current
(A)
Output
frequenc
y(Hz)
Rated
power
(kW)
Rated
voltage
(V)
SI21-D1 series, 60VDC
～
400VDC input, 3 phase 110VAC
～
230VAC output
0.75
0.75
110
1.0
400
175
～
380
7A
0
～
600
1.5
1.5
110
1.95
400
175
～
380
10A
0
～
600
SI21-D3 series, 150VDC
～
450VDC input, 3 phase 220VAC
～
240VAC output
0.75
0.75
220
1.0
450
360
～
430
4A
0
～
600
1.5
1.5
220
1.95
450
360
～
430
7A
0
～
600
2.2
2.2
220
2.86
450
360
～
430
10A
0
～
600
SI21-D5 series, 250VDC
～
780VDC input, 3 phase 380VAC
～
460VAC output
0.75
0.75
380
1.0
780
620
～
750
3.0
0
～
600
1.5
1.5
380
2.2
780
620
～
750
4.0
0
～
600
2.2
2.2
380
3.3
780
620
～
750
5.0
0
～
600
4
4
380
5.6
780
620
～
750
9.5
0
～
600
5.5
5.5
380
8
780
620
～
750
13
0
～
600
7.5
7.5
380
11.25
780
620
～
750
17
0
～
600
11
11
380
16.5
780
620
～
750
25
0
～
600
15
15
380
22.5
780
620
～
750
32
0
～
600
18
18
380
27
780
620
～
750
38
0
～
600
22
22
380
33
780
620
～
750
45
0
～
600
1.5 Cautions in Disposal
When you dispose frequency VFD, please pay attention to:
1. Electrolytic capacitor: the electrolytic capacitor of main circuit or the printing plate may explode when they are
burned.
2. Plastic: plastic incineration may generate toxic gases.
