When you need to control a motor, the first fork in the road is speed control versus starting control. A variable frequency drive (VFD) changes the frequency and voltage to control motor speed. A reduced voltage soft starter, by contrast, simply ramps the motor up to full speed while limiting inrush current. These two products land on opposite ends of that spectrum, and the right one depends almost entirely on your motor size and what you're trying to achieve.
Quick verdict
For a small three-phase motor fed from a single-phase 220 V supply, the 2.2 kW VFD at USD 65.83 is the clear pick. For a large motor that needs reduced voltage starting, the Square D Size 5 autotransformer soft starter at USD 4,750 is the only practical option here. The simplest and the most powerful motor controls in this comparison serve completely different jobs.
At a glance
| 1 to 3 Phase VFD | Square D Soft Starter | |
|---|---|---|
| Price | USD 65.83 | USD 4,750.00 |
| Horsepower | 3 HP | 200 HP |
| Condition | New | Used |
| Input voltage | 220 V single-phase | - |
| Output | Three-phase | - |
| Input current | 23A | - |
| Breaker | - | Breaker |
| Price bar |
Where each product wins
The 1 to 3 Phase VFD wins on price, compact size, and speed control. It's a low-cost way to get a three-phase motor running from a single-phase supply. It also includes useful operator controls like menu, enter, up, down, and shift keys directly on the unit.
The Square D Soft Starter wins on sheer power capacity. Rated for 200 HP and 250A, it's designed for industrial-scale motors. It uses an autotransformer to reduce voltage during startup, and its breaker-based design gives you a built-in protection element. It's a used unit, but it carries the Square D name.
1 to 3 Phase Variable Frequency Drive Inverter 2.2 KW VFD 220 V 3 HP
This drive is a compact option for small motor control. It takes a 220 V single-phase input and outputs three-phase power to run a 3 HP motor. The listed 23A input current and 10-95% relative humidity tolerance suggest it's built for ordinary light-industrial environments. The narrow body and independent air duct are designed to save cabinet space and keep heat dissipation efficient, which matters if you're installing several drives side by side. A strong point in its favor is the compact design and the ability to run a three-phase motor from a single-phase supply. Where it falls short is the power ceiling. It only handles 3 HP, so it's not suited to larger motors. Also, the keypad and menu navigation require a bit of learning, and the brand is listed as marddpair.
Square D Size 5 Reduced Voltage Motor Soft Starter 200 HP Autotransformer 250A
This is a serious piece of motor control hardware. Rated at 200 HP and 250A, it's meant for large three-phase motors that need a smoother start. The autotransformer design lowers the voltage during startup to reduce inrush current, then brings the motor up to full speed. The built-in breaker adds circuit protection at the starter level. It's a used unit, so its condition is part of the deal. What makes it worth the investment is the capacity: nothing else in this comparison can handle anywhere near 200 HP. The trade-off is the physical scale. A Size 5 starter is substantial, and it's designed for dedicated motor control centers rather than small cabinets.
Final choice by use case
- Small shop or hobbyist running a small three-phase motor on single-phase power: Choose the 1 to 3 Phase VFD. It gives you speed control and a compact footprint without a big investment.
- Industrial maintenance team starting a large motor: Choose the Square D Size 5 soft starter. It has the capacity and reduced-voltage starting your motor needs.
- On a tight budget and just need basic motor starting without speed control: If the motor is small, the VFD still makes more sense than buying an oversized starter. If the motor is large, the Square D is the necessary investment.
