In the world of soft starters and motor controls, choosing between these two is not about which is "better" overall; it is about which one matches the motor you need to control. One is a low-cost unit for residential air conditioning and generator power. The other is an industrial autotransformer starter built for a 200 HP motor. The $4,639.58 price gap makes the difference obvious: these are two different jobs.
Quick Verdict
For a 1.75-3.5 ton residential AC unit, the 8-16A AC Soft Starter is the obvious pick. It is new, affordable, and comes with the low-voltage, reverse-motor, and over-current compressor protection that smaller systems need. For a 200 HP industrial motor, the Square D Size 5 Reduced Voltage Motor Soft Starter is the one that can handle the load, but it is a used unit with a much higher price tag.
At a Glance
| Feature | 8-16A AC Soft Starter | Square D Size 5 |
|---|---|---|
| Price | USD 110.42 | USD 4,750.00 |
| Condition | New | Used |
| Soft start technology | Soft start | Reduced voltage autotransformer |
| Motor capacity | 8-16A, 1.75-3.5 ton AC units | 200 HP, 250A |
| Typical use | Residential AC, HVAC, generator power | High-horsepower motor starting |
Where Each Starter Wins
- The 8-16A AC Soft Starter wins on price, ease of setup, and fit for residential applications. Its protection set is designed around compressor loads and generator power.
- The Square D Size 5 wins on raw starting capacity. The 200 HP, 250A rating and autotransformer design put it in a completely different class for heavy motor controls.
Product Notes
8-16A AC Soft Starter
If your motor control job is a residential AC system between 1.75 and 3.5 tons, this soft starter is the one to grab. At $110.42, it is a low-cost way to get reverse motor protection, low-voltage protection, and over-current compressor protection in one package. It is listed as new and works with most residential AC units, as well as HVAC systems, EV chargers, solar setups, and generator power. The 230V rating and 8-16A operating range define its limits. That is also its limitation: you cannot step this up to a large industrial motor. If your load exceeds 16A or needs high-horsepower starting, this unit will not handle it. But for a residential or generator application, it delivers the protection you need.
Square D Size 5 Reduced Voltage Motor Soft Starter
The Square D Size 5 is an industrial soft starter. It is rated for 200 HP and 250A, placing it well above residential soft starters. The autotransformer design smooths starting current for large motors, and the unit is built for that kind of load. It is sold used, and at $4,750, it is a major investment. That price is the biggest limitation to swallow, especially for a used part. It is also more than needed for a small AC or generator setup, and the 250A capacity is not necessary for anything under 16A. If you are starting a 200 HP motor, this unit gives you the reduced-voltage starting you need, but you have to be ready for the cost.
Final Choice by Use Case
Pick the 8-16A AC Soft Starter if you need to protect a residential AC unit, HVAC system, or generator-fed compressor in the 1.75-3.5 ton range. Pick the Square D Size 5 Reduced Voltage Motor Soft Starter if you are starting a 200 HP industrial motor and need autotransformer-based reduced-voltage control.
