Evidence to watch
The function is proved by changed behavior, not by a parameter value alone.
- Actual-speed decay
- Motor current and torque during stop
- DC-bus voltage and braking state
F-22 · vendor-neutral function
VFD Stop Modes: Ramp, Coast, Quick Stop and DC Brake
A VFD can ramp the frequency down, remove torque and coast, use a faster quick-stop ramp, or apply DC injection braking. Each produces a different current, torque, stopping time and DC-bus response.
Why it matters
The behavior behind the parameter.
The correct stop mode depends on process risk, inertia and hardware. An aggressive ramp can regenerate energy into the DC bus; coast may be too slow; DC braking creates motor heating. None of these ordinary modes replaces STO.
- Ramp stop controls deceleration while the inverter remains active.
- Coast removes drive torque and lets machine inertia determine the stop.
- Quick stop and DC braking need explicit limits and thermal consideration.
Interactive proof
Test vfd stop modes: ramp, coast, quick stop and dc brake in three passes.
Keep the motor, load and starting condition constant. Change one function at a time, then use the electrical and mechanical evidence to explain the result.
- 01
Run the test bench at the same frequency and load for each mode.
- 02
Issue stop and compare actual-hertz decay, current and torque.
- 03
Shorten the ramp only after checking DC-bus rise and the braking arrangement.
Common commissioning mistakes
These errors can make a healthy drive appear faulty or create a misleading test.
- Selecting the fastest stop without considering regeneration.
- Using DC braking continuously.
- Calling an operational stop a safety-rated torque-off function.
Primary technical references
Transfer the concept; verify the exact drive.
This guide uses vendor-neutral terminology. For real equipment, use the manual for the installed model, option cards and firmware, plus the machine risk assessment and approved commissioning procedure.
Related VFD functions
F-25
VFD Flying Start Explained
Flying start—also called speed search or catch on the fly—estimates the speed and direction of an already rotating motor before the drive reapplies controlled torque.
Read and test F-41VFD Current Limit and Stall Protection
Current limiting caps drive output current and therefore available motor torque. The drive may slow or extend acceleration instead of immediately tripping when the load demand reaches that limit.
Read and test S-01VFD Safe Torque Off (STO)
Safe torque off prevents the drive from generating motor torque when its safety channels are de-energized. It does not isolate mains power and does not necessarily stop a moving machine quickly.
Read and testFrom explanation to evidence
