Softstarters

Use of a softstart bypass, either internal or external, allows an application to run continuously after the start in a closed contactor mode and to open once a stop or fault command has been provided. Whether using a fully solid state, or a hybrid softstarter, both are rated AC-53 but have different uses.

What are some of the main factors in determining if an application is better suited for a softstarter or a variable frequency drive? How do they compare in application uses, size or cost? Knowing the basics of how these two devices work may help determine which is best for your application.

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?

What is the difference between the PFB Softstarter Pump Stop feature compared to the PFS Softstarter Soft Stop feature?

What are the low energy ratings of the PCS or PF soft starter auxiliary contacts? Can they be used with electronics?

What is the metering accuracy of the PF softstarter LCD display? What are the tolerances of the parameters shown?

Can I use a single PCS or PF softstarter to control and start more than one motor at the same time or to start multiple motors simultaneously? What installation procedures, recommendations and programming parameters should be changed for this application?

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?

PF softstarter has an F38 Hall ID fault. This may occur when power pole or control module components are replaced in the field.

What are the differences between the options Normal, Up-To-Speed and External Bypass when configuring an auxiliary contact on a PF Softstarter? What terminals can be used on an PF Soft Starter to close and indicate that the unit is running?

Why is there voltage present on the load side terminals when using an PF/PCS soft starter and the motor is stopped with three phase power supplied to the input side of the controller?

What do F1, F2, or F3 Line Loss faults mean on the PF soft starter? These are pre-start faults. If these occur while the application is running, it would indicate that the control power could be momentarily dropping out and then doing a flying start. The pre-start fault would then be occurring during this re-start.

What will cause an Open Bypass fault code F13, F14, or F15 on a PF soft starter? What testing and troubleshooting steps can be taken to determine the cause of these faults?

Several scenarios may cause faults indicating a shorted SCR on PCS, PF or the PCE module of PCEC softstarters. Troubleshooting these faults can differ depending on the softstarter involved.

What do the faults of the LED Flashing 8, 11 or 12 times mean on a PCS softstarter? The PCS Troubleshooting guide defines LED Fault Flashes from 1 through 6, however 8, 11 and 12 are unpublished in the literature.

What are recommendations to protect PCS, PF and PCEC soft starters if a motor has a phase to phase fault? Circuit breakers and fast acting SCR fuses, which are normally located on the line side of the P Series soft starter, will not be effective to protect against a phase to phase fault on the motor side of the circuit.

When using any of the PCS or PF Softstart products, which starting mode or profile should I select? What is the difference between Current Limit and Soft Start starting modes? Which starting mode can reduce High Inrush Currents, Excessive Starting Torque, Peak Demand Utility Charges, Damage, Loss or Spillage of Product?

If the motor is not to full speed by the end of the PF softstarter ramp time when will the bypass engage? The PF soft starter product provides an enhanced up-to-speed detection scheme.

What will cause an open gate phase fault on the PF Softstarter? How do I troubleshoot these faults? The PF controller measures EMF and current. Both are used to determine if the SCRs are conducting.

How do I know if this is caused by bad line, faulty load or a suspect PF?

What is the cause or source of a 24 Volt Loss F45 fault? How can this fault be cleared? The F45 fault on PF softstarters can be caused by several conditions.

How does the Rotation Check and the Phase Reversal protection function on the PCS reduced voltage starter? Rotation Check is started when a start command is given to the PCS product. When there is a zero cross between 2-phases, a reading is taken and is stored in the PCS product's microprocessor. After so many degree changes in the voltage, another reading is taken and stored in the microprocessor and then repeated. At this time, a comparison is done in the microprocessor against known rotation patterns. Based on this comparison, the PCS knows whether the motor is going in a forward or reverse direction. (ROK29085)

Once the PF softstarter synchronizes itself to the incoming line power, it will continue to verify that all 3 line voltages are present (Note: For the PF softstarter to properly sync, at least one line must be detected). Several conditions will cause an F1 Line Fault.

What is the maximum three phase power cable length between the motor and PCS/PF Soft Start controller? Is there a need to connect a line reactor to eliminate grounding capacitor effect in long cable or wire runs?

Do I need to de-rate PCS/PF Soft Starters for higher altitudes? Above how many feet or meters must I derate the soft starter and what are the derating factors? What are the effects on the PCS/PF soft starter when used at altitudes above 2000 meters and why is derating necessary?

A PCS controller ramps the motor up to speed. At speed, the auxiliary contact closes. The PCS controller then stops the motor and restarts the motor continuously, and appears to pulse the motor. Why does the PCS soft starter continually start and stop the motor?

Why is my PF soft starter tripping on F40 No-load fault? The F40 fault is typically NOT a failure with the PF soft starter but improper parameter programming of the soft starter or an issue with other devices connected to it.

The PFD soft starter is generally able to stop the motor in about 1.5 times the maximum period it takes to successfully start the motor without faulting. In most applications the stop time will vary depending upon several factors.

What is the difference between a PCS and PCE softstarters? Will PCS work in an elevator application? The PCS and PCE (or PCEC) softstarters look similar, but have one major difference in the function of the 97/98 terminals.

What are the thread and bolt sizes used on the PCS and PF bus bars to mount the lugs? PCS and PF Softstarter hardware varies by unit size and is not available as renewal parts. Replacement parts can be obtained from your local hardware store. Follow these guidelines for specifications on each sized unit.

The PF Softstarter can be used in a variety of medium to heavy duty industrial applications that require special stopping, starting, ramp up or braking needs. Specifications and application techniques can be different for each application.

The softstarter has been given a start command and it displays "starting", however nothing is happening. What could be wrong?Answer: When the softstarter is given a start command it will indicate that it is starting and then check to see if the line and load connections appear correct and that the incoming power is good. If the softstarter enters this state, there are three possible reasons.

If the motor does not reach running speed at the end of the PCS soft start or current limiting period, what will the motor performance be?

Factors such as short and long term power requirements, power stability under varying loads, or possible future expansion should be taken into account when determining the necessary capacity of a generator for your PCS or PF Softstarter.

Surges or pressure transients occur in centrifugal pumping systems when any sudden change of flow is introduced. PFB Softstarters with Pump Control can reduce water hammering and fluid surges.

The softstarter typically is not the cause of the fuses blowing or a breaker tripping. Excess current demand can result in fuses blowing or breakers tripping.

The PF softstarters between 5 and 480 Amps are fitted with 2 sets of connection lugs on the load side (at the bottom of the unit). This is for the purpose of delta wiring a motor. See page 3-4, fig.3.5, of PF Softstarter User manual.Where a motor needs to be star wired (as in fig 3.4, same page of above publication), the motor cables should be connected to terminals 2/T1, 4/T2 and 6/T3. If a star wired motor is connected to terminals 8/T4, 10/T5 and 12/T6, the motor will run continually as soon as power is applied to L1, L2 and L3. Hence it will appear that the bypass contactor is short circuit. (ROK48493)

The PCS and PF can be used with a reversing starter to control the operation of a motor in either direction. The reversing contactor (or starter) can be wired before or after the softstarter, but the preferred way is to wire the contactor ahead of the softstarter (line side) in order to provide isolation. This will work with a softstarter with a minimum of a 1 second delay in the reversing cycle. Note: A softstarter cannot be "programmed' to switch a motor between forward and reverse. A separate reversing contactor must be used as described above. (ROK45932)

The LED comes on continually or faults out but there is no output. Check the setting of LINE / DELTA dip switch 15.

For additional information please contact your nearest authorized distributor, sales representative, or call our customer service or technical support lines.

A small percentage of Frame-2 PCE/PCEC Softstarters manufactured between February 2018 and August 2020 may experience phase-loss / open-load (four flash) faults as a result of an anomaly with the internal bypass contactors.

Feb 2024