PowerFlex 70

Good afternoon,

Recently, I bumped up the min. and max. frequency (located b/w Parameters 80-85) up to 130 Hz from 120. When I did this, the drive stayed at 0 Hz when it should have driven up to 130. I lowered both the min and max back down to 120, and then the drive proceeded to accelerate to 120 Hz like normal. Shouldn't this drive have a max cap at 180 Hz? I'm unsure why it won't accelerate whenever I bump up the the min and max above 120?

Thanks.

What is the value of Parameter 55?

There is an excellent diagram that goes along with Parameter 83 in the PowerFlex 70 User Manual that illustrates the relationship between Min/Max Speed, Max Frequency, and Over Speed Limit. An annotated screenshot of that is attached to this post.

My guess is that alive15 was seeing an Alarm code of 23, indicating a "MaxFreq Conflict".

Max Speed + Overspeed Limit must be <= Max Frequency

With default values: 120 + 10 <= 130

But when you increase Max Speed to 130, then the addition of the Overspeed Limit exceeds the Max Frequency and you get that MaxFreq Conflict and the drive gives you a configuration alarm and won't run.

The configuration fix for this, of course, is to set Parameter 55 (Max Frequency) to 140 Hz or higher.

The PowerFlex 70 will allow a Max Frequency value of up to 400 Hz on the standard models and 500 Hz on the Enhanced Control models.

The span of the 16-bit or 32-bit reference on the PowerFlex drives can be set for a top end at Max Speed *or* Max Freq on the Enhanced Control drives, so before discussing that we should know what model alive15 is using.

I am commissioning a squadron of PowerFlex 70's today and this has been a helpful refresher on that scaling so I can remember to document it in my commissioning notes !

Ken Roach said:

...

I am commissioning a squadron of PowerFlex 70's today and this has been a helpful refresher on that scaling so I can remember to document it in my commissioning notes !

Click to expand...

So is "squadron" the appropriate term of venery for PowerFlex 70s, or all PowerFelx drives, or all drives collectively regardless of brand? If there isn't one yet, I hereby nominate it!

I've used "gaggle" in the past, seemed like the right term at the time. Sometimes I want to refer to them like a collections of crows; a "murder"...

Parameter 55 was 130 Hz. I bumped it up to 170 Hz, and this allowed it to work.

Is it better to keep the over-speed limit low around 10? Couldn't you split it with parameter 55, like have both set at 70 Hz to get 130 Hz also? What parameter # is the over-speed limit by the way?

Thanks.