Help with a Powerflex 40

Okay so a little background on what I am trying to do.

I have a filler that fills ( as fillers usually do lol) three different size jugs. We use a Powerflex 40 with a potentiometer controlling the speed. On the largest jug the operate usually runs the machine too fast, but we need to run it that fast on the smaller sizes.

I am wondering if its possible with the Powerflex 40 to have one of the digital inputs change the maximum frequency when its active so that the max freq would be a lower value, but the operator would be able to control the speed up to the max freq via the potentiometer.

Is this possible, and if so how.

I see where I can have a preset speed via one of the digital inputs, but I want to be able to still control the speed via the pot, but not above the lower max freq when the digital input is active.

Any input is great. Thanks


Brandon

If I were you I would just set the max Freq to what you want. The POT will still work and the VFD will not go above the Maxuim set. P035 is the Parameter

After reading the manual I believe the answer to your question is NO.

If you have a spare analogue input and output channel on your PLC , you could connect the pot to the PLC which would then limit the pot's setting in logic . The output would then control your inverter's speed with the analog output connected to the inverter .

Paul

Try parameter A069 to set up a secondary speed.

This was suggested to me:

Is the potentiometer outside the Powerflex? ... Tes....Connect a resistor in series with the +10V lead and connect a switch or relay across the resistor.

With the switch or relay closed it will operate as it does now. With the switch open it will lower the 0-10V range.

Assuming a 1k pot, you could add a 250 ohm resistor to give 80% max speed. A 1k resistor would give 50% max speed. I believe you'd need a minimum 2 watt resistor.