Solar Pump Inverter Selector & PV Sizing Tool
Already have an AC water pump? Enter the motor nameplate data to find a preliminary SolarSeeker SP-series inverter match and a practical PV array target.
A solar pump inverter sizing calculator that starts from the pump you already own
Many solar pumping tools start with a new pump selection. This selector is designed for a different B2B situation: the customer already has an AC water pump and needs to know which solar pump inverter can run it and what PV array should be prepared.
The matching sequence is simple: pump power → rated voltage → phase → rated current → PV voltage window. If you need the full engineering method behind the decision, see our solar pump selection guide and the complete solar pump system design guide.
The tool first identifies the correct 220 V or 380 V output family and pump phase.
If rated current is entered, the recommendation moves up when the smaller model cannot cover the motor current.
The PV target comes from the current matching table. Panel Vmp and Voc are then used to test a practical series string.
Which SolarSeeker series matches your AC water pump?
The selector keeps each product family tied to its verified input/output role instead of choosing by kW alone.
| Pump / site condition | Verified output path | Typical selector route | Product page |
|---|---|---|---|
| 220–240 V single-phase AC pump | 220–240 V single phase | SP1 | SP1 single-phase inverter |
| 220–240 V three-phase pump + single-phase AC backup | 220–240 V three phase | SP2 | SP2 phase-conversion inverter |
| 220–240 V three-phase pump + three-phase AC source, or higher 220 V pump power | 220–240 V three phase | SP3 | SP3 three-phase inverter |
| 380–440 V three-phase AC pump | 380–440 V three phase | SP4 | SP4 380 V inverter |
SP5 and SP6 are intentionally not auto-selected in V1. SP5 is a custom solution, and SP6 is the verified IP55 outdoor controller route; both need project-specific review rather than a generic numeric recommendation.
How the solar panel recommendation is calculated
The recommended PV target is taken from the current SolarSeeker series matching table for the inverter model selected. When you enter a panel wattage, the calculator converts that target into a practical panel quantity.
For string layout, wattage alone is not enough. The tool needs the panel Vmp and Voc. It checks the recommended operating voltage used in the current Datasheets — at least about 320 V Vmp for the 220 V SP1–SP3 paths and about 530 V Vmp for the 380 V SP4 path — while keeping calculated string Voc below the verified 800 V maximum DC voltage.
If you are comparing common pump sizes, the existing 3 HP, 5 HP and 7.5 HP solar panel sizing guide gives additional examples. For panel-to-pump matching principles, see how to match solar panels with water pumps.
When should you send the pump nameplate for a final check?
Use the online result as a first-pass model and PV recommendation. A final project review is still recommended when the motor current is missing, the pump voltage is outside the standard 220–240 V or 380–440 V families, the calculated PV string cannot meet the voltage window, AC backup does not match the selected series, or the installation has long cable runs and unusual environmental conditions.
For a full selection, send the pump nameplate plus project location and available PV panel model. SolarSeeker can then verify inverter output current, DC string voltage and the final configuration before quotation. You can also browse the main solar pump inverter product range.
Solar pump inverter selector FAQ
What size solar pump inverter do I need for my water pump?
Start with the pump rated voltage, phase, motor power and rated current. The inverter output must match the motor voltage and phase, while its verified pump-power and output-current capacity must cover the motor. This tool applies those checks against the current SolarSeeker matching tables.
Can I convert an existing AC water pump to solar power?
In many cases, yes. The existing AC pump can remain in place when a solar pump inverter provides the correct motor output and the PV input is designed within the inverter DC voltage window. Final compatibility still depends on the pump nameplate and installation conditions.
How many solar panels do I need for a water pump?
The number depends on the inverter’s PV target, panel wattage and the module Vmp/Voc. This calculator first estimates the panel count from the current SolarSeeker matching table and then checks a possible series string when panel voltage data is supplied.
Why does rated motor current matter if I already know the pump kW?
Two pumps with the same kW can have different rated currents. A model that looks large enough by power can still be undersized by current, so the selector uses rated current as an additional gate and moves up to a larger verified inverter model when needed.
What is the difference between SP2 and SP3 for a 220 V three-phase pump?
Both are 220–240 V three-phase pump-output routes, but their verified AC input roles differ. SP2 accepts 220–240 V single-phase AC input, while SP3 uses 220–240 V three-phase AC input and covers a wider pump-power range. Solar-only projects can be routed by pump power; hybrid projects should also match the available AC source.
Is the calculator result a final engineering design?
No. It is a preliminary selection based on verified product matching data. Final sizing should check the pump nameplate, panel model, cable length, site solar resource, head/flow duty and grid or generator conditions.
Want SolarSeeker to verify the result?
Send the pump nameplate, panel model and project country. We can confirm the inverter model and PV configuration before you quote or order.