3.7 kW Single Phase to Three Phase Frequency Inverter

$294.31

| 7 review(s) | Add your review

3.7 kW variable-frequency inverter for sale, converting single-phase to three-phase, suitable for motors, pumps, washing machines, refrigerators, fans, and so on. It comes with RS485 communication mode and IP20 enclosure protection; the single-phase to 3-phase inverter works at (–10℃, 40℃). The shell is hard and can protect the internal components of the inverter.

Free shipping

Delivery date: 3-10 days

SKU: GK3000-2S0037

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Overview
Specs
FAQ
Reviews

Overview

The inverter is a 3.7kW (5 hp) variable frequency drive that converts single-phase 220V AC input into three-phase AC output, enabling three-phase motors to operate on a standard single-phase power supply — without a utility three-phase service upgrade or rotary phase converter.

With a rated output current of 17A and 150% overload capacity for 60 seconds, this drive handles constant-torque loads reliably. Verified customer applications include three-phase lathes, workshop water pumps, air compressors, milling machines, and conveyor systems.

Three control modes are available: V/F control for general variable-speed operation, sensorless vector control (SVC) for tighter torque regulation without an encoder, and speed sensor vector control (FVC) for closed-loop encoder-feedback applications. Built-in PID supports direct sensor input for closed-loop pressure or flow control. RS-485 Modbus enables PLC integration.

Feature

Single-Phase In, Three-Phase Out: Accepts standard 220V single-phase input (±15%, 50/60Hz) and outputs balanced three-phase AC at 0 to rated input voltage, allowing three-phase motors to run on single-phase supply with no additional equipment.
Three Control Modes: V/F, SVC, and FVC: Supports V/F control for general applications, sensorless vector control (SVC) for encoder-free torque regulation, and speed sensor vector control (FVC) for closed-loop encoder feedback.
150% Start Torque at 1 Hz: Delivers 150% of rated torque at 1 Hz for reliable starting under full load, with 150% overload capacity for 60 seconds and 180% for 3 seconds — handling compressor and conveyor startup loads without tripping.
Built-in PID & Automatic Energy Saving: Integrated PID controller accepts pressure, flow, or temperature sensor input for closed-loop control without an external controller. Automatic energy-saving mode optimizes the V/F curve based on actual load to reduce unnecessary power draw.
RS-485 Modbus & Comprehensive Protection: RS-485 Modbus RTU communication for PLC/SCADA integration. Built-in protection covers overvoltage, undervoltage, overcurrent, overheating, phase loss, and short circuit, with automatic current limiting to prevent nuisance tripping.

Details

Digital Display

The LED display shows real-time output frequency, voltage, current, motor speed, and running direction. Fault codes are displayed immediately on alarm — the drive logs up to 30 fault types in history for on-site diagnostics without connecting to a PC.

Multi-function Button

The keypad provides direct access to start, stop, forward/reverse, jog, and parameter programming. Frequency setpoint can be adjusted in real time during operation. For remote or automated operation, all functions are also accessible via the RS-485 Modbus interface.

Cooling Fan

The intelligent variable-speed cooling fan activates based on internal temperature rather than running continuously, reducing noise during light-load operation. Customer reports confirm stable thermal performance across 8-hour continuous shifts at ambient temperatures up to 35°C.

Use Cases

Workshop Lathes & Machine Tools: The most commonly cited application in customer reviews. Sensorless vector control maintains stable cutting torque at variable spindle speeds, and the 5 hp (3.7kW) rating covers most bench lathes and small milling machines. Setup requires entering motor nameplate data.
Three-Phase Water Pumps: Run a three-phase pump on single-phase workshop or agricultural supply. Built-in PID accepts a pressure transducer signal for constant-pressure control, eliminating pressure fluctuations without an external controller. Customers report smooth, quiet operation even during long daily runs.
Air Compressors: 150% overload capacity for 60 seconds handles compressor motor startup loads reliably. Variable-speed operation matches air output to demand, reducing energy consumption compared to fixed-speed direct-on-line starters.
Conveyor & Industrial Equipment: Adjustable acceleration and deceleration ramps eliminate belt jerk on startup, reducing mechanical wear. Multi-step speed settings allow pre-programmed speed profiles for automated processes via Modbus.

Applications

Medical Equipment

Solar Power Generation

Electric Vehicle Charging

Office Equipment

Specs

Basics	Model	GK3000-2S0037
	Capacity	3.7 kW (5 hp)
	Shipping weight	4 kg
	Dimension	230118153 mm
I/O Feature	Rated current	17 A
	Input voltage	1 phase 220V AC ±15%
	Input frequency	50Hz/ 60Hz
	Output voltage	3 phase AC 0~input voltage
	Output frequency	0Hz~1000Hz
	Overload capacity	150% of rated current for 1 minute, 180% of rated current for 3 seconds
Control Feature	Control mode	V/F, Sensorless vector control (SVC), Speed sensor vector control (FVC)
	Communication	RS485
	Speed regulation	1:100
	Start torque	150% of rating torque at 1 Hz
	Speed control accuracy	≤±0.5% of rating synchronous speed
	Frequency precision	Digital setting: max frequency x± 0.01%; Analog setting: max frequency x± 0.2%
	Frequency resolution	Analog setting: 0.1% of max frequency; Digital setting: 0.01Hz
	Torque boost	Automatic torque boost, manual torque boost 0.1%~30.0%
	Interior PID controller	Be convenient to make a closed-loop system
	Automatic energy save running	Optimize V/F curve automatically based on the load to realize power-saving running
	Automatic voltage regulation (AVR)	It can keep constant output voltage when power source voltage varies.
	Automatic current limiting	Limit running current automatically to avoid frequent over-current, which will cause trip
Environment	Enclosure rating	IP 20
	Temperature	–10℃~ +40℃; VFD will be derated if ambient temperature exceed 40℃; each rise 1℃, the derate will be 5%
	Humidity	5%-95%, without condensation
	Altitude	≤1000m; VFD will be derated if above 1000m
	Impingement and oscillation	Normal running:<5.9m/s2 (0.6g); Transportation:<15m/s2 (1.5g)
	Store environment	–20℃~ +60℃; no dust, no corrosive gas, no direct sunlight

FAQ

Q1: How to test a single-phase to three-phase frequency inverter?

Power supply check: Before turning on the power, use a multimeter or voltmeter to check whether the voltage and frequency of the input power supply meet the specifications of the frequency inverter.
Start the frequency inverter: Start the inverter 1-phase to 3-phase correctly according to the operating instructions of the frequency inverter. Observe the display panel of the inverter to ensure that the display is normal and there are no faults or error messages.
Output voltage and frequency test: Use a multimeter or oscilloscope to measure the output voltage and frequency of the inverter. Make sure the output voltage and frequency are consistent with the set values and are stable without fluctuations.
Load test: Connect an appropriate load to the output end of the frequency inverter and observe the operating status of the frequency inverter. Gradually increase the load, check whether the inverter can work stably, and observe whether the output voltage and frequency change.
Functional test: Test various frequency drive inverter functions, such as speed regulation, forward and reverse rotation, protection, etc. Make sure these features are working properly and as expected.
Abnormal test: Simulate some abnormal situations, such as input voltage being too high or too low, load short circuit, etc., to check whether the inverter can respond correctly and take corresponding protective measures.

Q2: What is the maximum single-phase input current for the 3.7kW model?

At 3.7kW (5 hp) output with single-phase input, the input current is approximately 34–38A at 220V. A dedicated 40A circuit breaker and appropriately rated single-phase wiring are required. Do not run this drive on a shared residential circuit — the high input current demand requires a dedicated feed.

Q3: Does this drive support encoder feedback (closed-loop vector control)?

Yes. In addition to V/F and sensorless vector control, the GK3000-2S0037 supports speed sensor vector control (FVC) with an encoder. This is the highest-precision control mode, providing tighter speed regulation than sensorless SVC. An encoder and PG card are required for FVC mode — contact us to confirm compatibility with your motor and encoder.

Q4: Can I use this VFD to run a three-phase motor in reverse?

Yes. Forward and reverse rotation are selectable via the keypad, a digital input terminal, or Modbus command. No rewiring of the motor is required — direction change is handled entirely in the drive. Acceleration and deceleration ramp times for direction reversal are independently configurable.

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Existing reviews

Good performance for workshop equipment

I bought this 3.7 kW single-phase to three-phase frequency inverter to run a three-phase water pump in my workshop. The installation took a little time because I had to adjust some parameters, but once everything was set up, the motor ran smoothly and much quieter than before. The housing feels solid and durable, and the cooling performance has been reliable even during long operating hours.

From: Hale Birrell | Date: 5/26/2026 12:31 AM

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Worth every penny

I bought this 3.7kW inverter to run my old three-phase lathe on a single-phase supply, and it’s been good. The setup was straightforward—I plugged it in, connected via RS-485 to my system, and it powered up smoothly. It also keeps cool even during 8-hour shifts in 35℃ heat.

From: Buck Yerkes | Date: 9/28/2025 7:17 PM

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Good performance frequency inverter, but a bit noisy.

This 3.7kW frequency inverter does a solid job converting 1-phase to 3-phase power, and it runs my motor smoothly. The build feels sturdy, and the RS485 communication is a nice feature. However, it does produce some noise when running, which might be a downside for quieter workspaces.

From: Uriah Rhys | Date: 3/13/2025 7:31 PM