SI21 Solar Pump VFD Manual
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3) Common problems and solutions
a. Q:Well-lit conditions, the pump is running, but the water is very small.
A:Check if the pump motor direction is reversed.
b. Q:Well-lit conditions, the drive is in standby mode 0.00Hz.
A:Check F21.01, observe what protection status is the drive in currently, check whether the parameters set is
reasonable.
c. Q:DC current is incorrectly displayed.
A:Adjust F21.30, F21.31 for calibration.
d. Q:Well-lit conditions, frequency severe beating during operation.
A:Reasonably adjust F21.06 value, the adjustment is recommended to be in the vicinity of the default, too big or
too small will cause frequency oscillation.
6.3 PV Water Pump Features
1) Sleep Function
During the photovoltaic pump operation, the VFD will go into sleep state when the DC voltage provided by
solar panels is lower than F21.11 (sleep voltage threshold) due to objective factors, while the keyboard warning
“A.LPn”; when DC voltage provided by solar panels rises back to F21.12 (sleep recovery voltage) point, start
timing and after F21.13 (sleep shutdown waiting time), the drive starts running.
2) Low-frequency Protection Function
During the operation of the photovoltaic pump, for some reason, the output frequency is lower than F21.14
(low frequency detection frequency), and after F21.15 (under frequency detection time) time, enters into the
standby protection state, while the keyboard warning “A.LFr”; after entering into the standby protection state and
after F21.16 (frequency protection automatic recovery) time, automatically resume to running state.
3) Dry Run Protection
During the operation of the photovoltaic pump, for some reason, the output current is less than F21.17 (dry
protection current detection), and after F21.18 (dry protection detection time) time, enters into standby protection
state, while the keyboard
warning “A.LuT”; after entering into the standby protection state and after F21.19 (dry protection automatic
recovery)time,
automatically resume to running state.
4) Over-current Protection
During the operation of the photovoltaic pump, for some reason, the output current is greater than F21.20(over
current point setting), and after F21.21 (over current protection detect) time, enters into standby protection state,
while the keyboard warning “A.oLd”; after entering into the standby protection state and after F21.22 (over current
protection auto restore working )time, automatically resume to running state.
5) Minimum Power Protection
During the operation of the photovoltaic pump, for some reason, the output power is less than
