SD600 Series MPPT Solar Pump Inverter for Agricultural Irrigation

Product Overview

The SD600 Series MPPT Solar Pump Inverter converts DC power from a photovoltaic array into variable-frequency AC output for agricultural irrigation pumps. By adjusting output frequency as solar conditions change, it coordinates available PV power with the operating requirements of the connected pump.

The series supports both solar DC and compatible AC power sources. An AC supply can support pump operation when solar power is unavailable or insufficient, depending on the selected system configuration.

Available functions include MPPT control, automatic start and sleep, soft starting, dry-run protection, water-level control, PQ curve monitoring, RS485 communication, and optional remote access. Configurations are available for both 220V and 400V pump systems.

MPPT Solar Pump Control

Real-Time Solar Tracking

The built-in Maximum Power Point Tracking algorithm monitors the PV array and adjusts the inverter operating point as sunlight and panel temperature change.

MPPT tracking efficiency reaches up to 99% under the stated operating conditions. Actual water output still depends on solar irradiance, PV array sizing, total pumping head, pipe losses, pump efficiency, and motor performance.

Variable-Frequency Pump Operation

Instead of treating solar input as a fixed power source, the SD600 adjusts motor frequency according to the power available from the PV array.

Under stronger sunlight, the pump can operate at a higher frequency and deliver more water. When solar input falls, the inverter reduces output frequency or enters sleep mode rather than repeatedly attempting a full-power start.

This control method helps make practical use of changing solar conditions throughout the day.

Automatic Start and Sleep

After the required system parameters are configured, the inverter can start the pump when adequate PV power becomes available. It can reduce output or enter sleep mode when the available input falls below the operating threshold.

Automatic operation reduces the need for daily manual switching at remote irrigation sites.

AC/DC Power Operation

The SD600 can be configured for solar DC input and compatible AC power input. This allows the irrigation system to use solar energy as its primary source while retaining grid or generator power as an alternative.

AC support can be useful when:

• Irrigation must continue after sunset

• Cloud cover reduces PV output

• Seasonal water demand exceeds daytime solar capacity

• The system requires scheduled pumping

• Water storage must be replenished within a fixed period

The AC supply voltage and phase must match the selected inverter configuration. Source changeover, isolation, protection, and operating priority should be defined during system design.

The SD600 is battery-free in most solar pumping applications. Where night-time water availability is required, storing water in a tank or reservoir is often more practical than storing electrical energy in batteries.

Automatic Pump Operation

Soft Starting

The inverter increases motor speed gradually rather than applying full-frequency power immediately. This reduces startup current and helps limit abrupt changes in pipeline pressure.

Acceleration time should be adjusted according to the pump, pipe length, check valve, delivery head, and irrigation layout.

PQ Curve Monitoring

The custom PQ function uses pump power and flow information to support estimates of operating flow, accumulated water delivery, and energy production.

For meaningful results, the correct pump curve and system information must be entered during setup.

Water-Level Control

A water-level probe can be connected for source and tank monitoring. The inverter can use the water-level signal to stop pumping when the source level is too low or when a storage tank reaches its configured limit.

Timed Operation

Timing functions can be used where irrigation must follow planned operating periods. This is useful for crop zones, reservoir filling, scheduled water transfer, or locations with limited AC backup availability.

Cleaning Functions

Configurable pump-cleaning functions can assist applications where sediment or debris may affect operation. The cleaning sequence and permitted pump direction must be matched to the pump manufacturer’s instructions.

Pump Protection

The SD600 includes drive and pump protection functions intended to respond to common electrical, thermal, and water-supply faults.

Dry-Run Protection

Dry-run detection can stop the pump when the inverter identifies an underload condition associated with insufficient water. A low-water probe can provide an additional water-level signal.

Dry-run parameters must be commissioned for the actual pump because normal load current varies with pump type, head, flow, and operating frequency.

Electrical Protection

Available protection functions include:

• PV overvoltage protection

• Motor overcurrent protection

• Pump phase-loss protection

• Maximum pump-current protection

• Low input-power protection

• Overload protection

• Inverter overtemperature protection

• Automatic derating at high temperature

The cause of a recurring fault should be identified before the inverter is restarted.

Minimum Stop Frequency

A minimum operating frequency can be configured to prevent the pump from running continuously at a speed that cannot produce useful water flow or adequate motor cooling.

The correct threshold depends on pump design, static head, pipe resistance, and motor requirements.

Water-Level Protection

Source-level and tank-level signals can be used to prevent dry running or tank overflow. Probe location, cable routing, input logic, and sensor type should be considered during installation.

Pump and Motor Compatibility

The SD600 is designed primarily for compatible AC water-pump motors used in solar pumping systems.

Common applications include:

• Submersible borehole pumps

• Deep-well pumps

• Surface centrifugal pumps

• Irrigation booster pumps

• Reservoir transfer pumps

• Compatible single- and three-phase pump systems

Motor selection should be based on more than rated power. Before choosing an inverter, check:

• Motor rated voltage

• Motor phase

• Rated current

• Rated power

• Motor frequency

• Pump starting requirements

• Required flow

• Total dynamic head

• Daily pumping volume

• Motor cable length

A pump should not be connected until the output voltage, phase, current, and supported motor type have been matched to the selected SD600 configuration.

Monitoring and Communication

Each SD600 solar pump inverter is equipped with an RS485 interface for local communication and system integration.

Optional communication modules include:

• GPRS

• WiFi

• Ethernet RJ45

When the appropriate module and platform are installed, operators can review operating data through an Android or iOS application.

Available monitoring information may include:

• PV input status

• Output frequency

• Pump operating current

• Running status

• Fault events

• Historical operating data

• Estimated flow and accumulated water delivery

Remote access is useful for irrigation systems spread across large farms or installed in locations that are difficult to inspect every day.

Network availability, module type, platform access, and supported remote functions should be defined when ordering.

Agricultural Irrigation Applications

Field Irrigation

The SD600 can drive pumps that transfer water from wells, reservoirs, canals, or storage tanks to field irrigation networks. Variable-frequency operation allows pump output to follow the solar energy available during the day.

Orchard Irrigation

Orchards often require regular water delivery across widely spaced planting areas. A solar pumping system can fill an elevated tank or supply a compatible irrigation network during available daylight hours.

Greenhouse Water Supply

Greenhouses can use the inverter for source-water transfer, tank filling, circulation, or irrigation supply. Water-level and timing functions help coordinate pumping with daily irrigation plans.

Deep-Well Pumping

The SD600 can be applied to compatible submersible pumps for extracting groundwater. Borehole depth, static water level, drawdown, pipe diameter, and pump cable length must be included in the system calculation.

Livestock Watering

Remote farms can use solar pumping to transfer water to livestock tanks or reservoirs. Tank-level control can stop the pump when the selected storage level is reached.

Reservoir and Tank Filling

Water can be pumped during periods of good solar production and stored for later use. This separates water availability from momentary sunlight without requiring a battery bank in most applications.

Solar Pump System Design

Define the Water Requirement

Start with the required daily water volume and operating period. Irrigation area alone is not enough to select a pump because crop type, climate, irrigation method, soil, and seasonal demand affect water use.

Calculate Total Dynamic Head

Total dynamic head includes:

• Vertical lift from the water source

• Drawdown in the well

• Delivery height

• Friction loss in the pipe

• Losses through valves, filters, and fittings

• Required pressure at the irrigation outlet

Use the calculated flow and head to select the pump before selecting the inverter.

Match the Inverter to the Motor

The inverter output voltage, phase, rated current, and overload capacity must match the pump motor. Select by rated current as well as motor power.

Size the PV Array

The PV string must remain inside the applicable SD600 voltage range during normal operation. The cold-weather open-circuit voltage must remain below the maximum input voltage.

The recommended PV input power is at least 1.2 times the pump capacity. Additional array margin may be required for high temperatures, weak sunlight, seasonal conditions, dust, cable losses, and module aging.

Plan Water Storage

A storage tank or reservoir allows water pumped during sunny hours to be used later. Storage volume should reflect daily demand, weather variation, irrigation schedule, and the time required to refill the tank.

Check the Motor Cable

For a motor cable longer than 70m, an output reactor with a rating matched to the inverter may be required. Cable size, voltage drop, insulation, shielding, grounding, and local electrical requirements should also be checked.

Technical Specifications

Quality and Engineering Support

IFIND applies an ISO 9001 quality management system and reports CE certification and BV field verification completed in 2024. Each inverter is assembled and tested before packing.

Engineering support is available for:

• Pump and inverter selection

• PV string calculations

• AC/DC supply configuration

• Water-level sensor setup

• Motor parameter configuration

• RS485 and remote monitoring

• Fault diagnosis

• Irrigation project matching

Customers can submit the pump nameplate, pump curve, daily water demand, total head, solar panel specifications, and site power information for technical review.

FAQs

Can the SD600 operate without batteries?

Yes. Most solar water-pumping systems can operate directly from the PV array. Water can be stored in a tank or reservoir for use when the pump is not operating.

Can grid or generator power be used when sunlight is insufficient?

The SD600 supports compatible AC and solar DC power sources. AC voltage, phase, switching method, and source priority must match the selected inverter configuration.

How many solar panels are required?

The number depends on panel Voc, Vmp, current, power, site temperature, pump power, and the selected SD600 voltage class. The complete string must remain inside the inverter’s voltage and current limits.

Why is the PV array rated above the pump power?

The page recommends PV power of at least 1.2 times the pump capacity. This margin helps account for module temperature, irradiance changes, cable losses, dust, and other real operating conditions.

What happens if the well runs out of water?

The inverter can use dry-run detection and a low-water probe to stop the pump. The detection threshold and restart delay should be configured for the actual water source and pump.

Can the inverter maintain constant water flow all day?

Water flow normally changes with available solar power unless an AC source, storage system, or compatible control strategy is used. A storage tank can help provide a more consistent water supply to the irrigation network.

Can the SD600 operate a single-phase water pump?

The product information references support for different pump-motor types, but compatibility depends on the selected SD600 model. Provide the motor nameplate and wiring information before ordering.

Is remote monitoring included as standard?

RS485 is standard. GPRS, WiFi, and Ethernet modules are optional. Confirm the communication module, application platform, regional network compatibility, and remote functions in the quotation.

Is the standard inverter enclosure IP65?

An IP65 cabinet configuration is available as an option. The installation location should be selected according to the enclosure supplied with the order.

When is an output reactor required?

The product page recommends considering an output reactor when the motor cable exceeds 70m. Cable length, switching frequency, motor insulation, and installation environment should also be evaluated.

What information is needed to select the correct SD600 model?

Provide the pump type, motor voltage, phase, power, rated current, required flow, total dynamic head, motor cable length, PV module specifications, available AC supply, and installation environment.