Help with a Powerflex 40

[bcard519]

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:?

 

[Rampage_Rick]

Is the potentiometer outside the Powerflex? 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.

 

[just the cowboy]

yep I do it that way

yep I do it that way

Is the potentiometer outside the Powerflex? 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.

I do it that way on a lenze drive works great.

 

[Jraef]

The PF40 doesn't have that ability, but I think you can "trick" it onto doing this.

The drive has 2 current limit capabilities and the 2nd one can be called for with a digital input. When the drive has to limit the current under a load, it does so by lowering the frequency until the current drops, over riding all other speed commands.

So what you would do is to experiment with the current limit 2 setting so that it effectively limits the maximum speed. You can't predict what that level of current that will be, hence the experimenting. But let's say that level is 75% of FLC. So you would set Current Limit 2 at 75%, then program one of your digital inputs to call for CL2 when you want to fill the large jug. The analog input will still work the same, but only until it reaches 75% of FLC, then it will stop accelerating even if the dial is turned up.

 

[Aleman]

The PF40 doesn't have that ability, but I think you can "trick" it onto doing this.

The drive has 2 current limit capabilities and the 2nd one can be called for with a digital input. When the drive has to limit the current under a load, it does so by lowering the frequency until the current drops, over riding all other speed commands.

So what you would do is to experiment with the current limit 2 setting so that it effectively limits the maximum speed. You can't predict what that level of current that will be, hence the experimenting. But let's say that level is 75% of FLC. So you would set Current Limit 2 at 75%, then program one of your digital inputs to call for CL2 when you want to fill the large jug. The analog input will still work the same, but only until it reaches 75% of FLC, then it will stop accelerating even if the dial is turned up.

I thought it did have the 2 speed capability. I'm pretty sure I had a machine that had a foot pedal switch to drop speed by half. Used digital inputs 1 and 2 for speed selection switch(es). P038 is set for preset freq. Then A051 and A052 assign the inputs 1 and 2 to preset freq. A071 and A072 set the speeds.

Manual here: http://www.camcoindex.com/Svcman/A-B_Powerflex_40_QuickStart.pdf

 

[Aleman]

Oh. Re read the OP and see that wasn't what he asked. And I was sitting here wondering how did Jraef not know that :ashamed1: