Is the PF softstarter able to create and develop full torque to the motor when performing a Slow Speed Low or High operation?
How much motor torque can the PF soft starter produce in the Slow Speed mode?
How does the PF soft starter create or produce Slow Speed to the motor?
Why doesn't the PF soft starter develop full torque in slow speed mode?
The PF soft starters in the slow speed (forward or reverse) mode will not generate full torque. We do not have a value or calculation of the amount of reduced torque at Slow Speed Low (7%) or at Slow Speed High (15%) of full speed with the PF soft starter product.
How The PF Soft Starter Produces Slow Speed
There are a couple of different ways of producing slow speed to a motor using a soft starter product. One of the ways is to use Cycle Skipping as shown in current curve plot below. This is typical of many soft starters where the current pulses are controlled by the silicon-controlled rectifier (SCR) and fired for portions of every few line cycles allowing for slow speed control. A pseudo sine wave output to the motor is produced. The amount of Torque produced during slow speed in this method is pretty limited.