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PF Soft Starter Jam and Underload Detection

Question:

When does the PF Soft Starter product detect jam and underload conditions? Are they detected when these parameters are enabled by the end user during the programming and initial setup?

Answer:

Both Jam and Underload detection become active, once the PF Soft Starter detects that the motor is up to speed. The display on the PF will show 'At Speed' or 'Running'.

The Jam and Underload detection will be inactive during the ramp time and also when a Stop command is issued this detection will be inactive.

Typically, Jam and Underload conditions are motor running faults (or alarms) as they are configured as a percent of FLC (full load current) parameter.

If the PF product, while running, would transition from internal bypass contactor control to SCR control (occurs when the motor current is above 120% of the PF rating), the Jam fault (or alarm) is still being detected by the PF Soft Starter but Underload detection will be inactive.