Wiring of VFD

Cactus1549

Primary circuit wiring

For three-phase AC input, connect to the terminal "R" "S" "T", For single-phase AC input, connect any two of the terminal "R" "S" "T", it is recommended to use R and T.
For the DC (solar) input, connect to the terminal "+" "-". If the solar and AC power may be input at the same time, please add anti reflection diodes at the PV side to protect the solar panel.
Three phase motors are connected to terminal "U" "V" "W" at the output side. And single-phase motors are connected to terminal "V" "W" . However, we do not recommend using single-phase motors on the VFD.
https://www.solar660.com/d/7-why-is-the-vfd-not-suitable-for-single-phase-motors

Secondary circuit wiring

The common terminal is COM or GND.
DI1 is the enabling terminal. If you want to use this terminal, set P0-02 = 1. In this way, you can control the start and stop of the VFD by connecting or disconnecting the connection between DI1 and COM. Or in PV mode, keep DI1 and COM connected, so that when there is sufficient light, the VFD will run automatically.
DI2 and DI3 are used for full water protection at the outlet and water shortage protection at the inlet. When you want to use these two functions, please follow the following method
First, place the other side of the wire connecting DI2 and COM on the upper side of the water pool at the outlet. When they are connected, the full water protection is triggered and A-tF is displayed. When they are disconnected, the full water protection is released.
Then place the other side of the wire connecting DI3 and COM on the upper side of the water inlet of the water pump. When they are disconnected, the water shortage protection is triggered and A-tL is displayed. When they are connected, the water shortage protection is released.
Next, set
H3-01 = 4, indicating that the water shortage detection from the DI terminal is accepted
H3-05 = 4, indicating that the full water detection from the DI terminal is accepted
P4-01 = 101, indicating that the DI2 terminal accepts the water level warning signal
P4-02 = 102, indicating that the DI3 terminal accepts the water level warning signal
P4-38 = 00100, each number from right to left represents the logic state from DI1 to DI5, "0" represents positive logic, that is, the DI terminal and COM are connected to indicate a warning, and disconnection indicates no warning, "1" represents negative logic, that is, the DI terminal and COM are connected to indicate no warning, and disconnection indicates a warning. When there is water at the water pump inlet, DI3 and COM are connected, so the negative logic should be used to change the parameter corresponding to DI3 to "1".
H3-03 indicates the water shortage alarm delay, the default is 10s, which can be modified as needed.
H3-04 indicates the water shortage reset delay, the default is 300s, which can be modified as needed.
H3-07 indicates the full water alarm delay, the default is 10s, which can be modified as needed.
H3-08 indicates the full water reset delay, the default is 300s, which can be modified as needed.

Cactus1549

ep20-solar-vfd.pdf

1MB

solar-pump-inverter.pdf

21kB

ZZZ

How to set the minimum operating frequency of the water pump？

Cactus1549

ZZZ
In my opinion, the critical point is the frequency at which the pump can just discharge water, which usually requires on-site commissioning to determine this frequency.
Below this frequency, the pump is working but no water is discharged, which has no practical significance and increases the risk of equipment, while above this frequency, it is not conducive to the effective use of solar energy.

Soppose the point is 30Hz, set as following:
P0 -14 = 30,
P8 -14 = 1, indicating that when the operating frequency is lower than the minimum value, the water pump will shut down.