Soft starter vs VFD
Selection depends on the application, operating demand, and equipment. This table shows how the two options generally compare.
| Factor | VFD | Soft starter |
| Speed after startup | Adjustable across the operating range | Typically full line speed after the ramp |
| Startup | Controlled ramp of speed and voltage | Controlled ramp of voltage |
| Typical fit | Loads where demand varies, such as fans and pumps | Constant-speed loads that need gentler starts, such as conveyors and belts |
What TSI delivers
- Motor fleet scan. TSI reviews a customer’s motor list to identify where VFDs or soft starters may make sense.
- VFD application review. TSI evaluates where variable speed control could match motor output to actual operating demand.
- Soft starter review. TSI identifies motors where smoother ramp-up may reduce mechanical shock, belt stress, pipe stress, or startup wear.
- Motor control planning. TSI prioritizes opportunities by application, operational impact, and planning need.
- Rockwell Automation coordination. TSI is an authorized Rockwell Automation distributor in select parts of New York and New Jersey. TSI coordinates with automation partners where Rockwell or other automation solutions are part of the project scope.
- Contractor support. TSI works alongside electrical contractors and installation partners where implementation is required.
How a motor control plan takes shape
- Submit. The facility shares its motor list.
- Scan. TSI reviews the list to identify candidates for VFDs or soft starters.
- Review. TSI evaluates each candidate by application.
- Prioritize. TSI ranks opportunities by operational impact and planning need.
Frequently asked questions
What is the difference between a VFD and a soft starter?
A VFD adjusts the frequency and voltage supplied to a motor, which controls motor speed during operation. A soft starter ramps voltage during startup, and the motor then typically runs at full line speed.
When does a soft starter make sense?
A soft starter makes sense for motors that run at constant speed and need a smoother ramp-up. TSI Turtle Services identifies motors where a gentler start may reduce mechanical shock, belt stress, pipe stress, or startup wear.
When does a VFD make sense?
A VFD makes sense where motor output can follow operating demand, such as variable-demand fan and pump systems. TSI evaluates each application to find where variable speed control could help.
What is a motor fleet scan?
A motor fleet scan is a review of a facility’s motor list to identify where VFDs or soft starters may make sense. The scan produces the starting point for a prioritized motor control plan.
Does TSI install VFDs and soft starters?
TSI plans motor control and coordinates with electrical contractors or installation partners where implementation is required. TSI also coordinates with automation partners where Rockwell or other automation solutions are in scope.
What does a full-voltage motor start do to equipment?
A full-voltage start delivers a sudden surge of torque and current, which can add mechanical shock, belt stress, and pipe stress at startup. Soft starters and VFDs ramp the start, which can reduce that stress.
Let's discuss your project requirements
