When I calculate a command for a VFD, I try to include the whole derivation in the rung comments. That helps future troubleshooters (frequently including myself !) figure out what ratios and limits I was considering.
I presume you're sending the speed reference value to the PowerFlex 700H drive over Ethernet or ControlNet.
For those who haven't used them, the PowerFlex 700H was a large-frame version of the PowerFlex 700. "H" for "Heavy" or "Huge" or "Honking"; they ranged from 200 to 1000 horsepower.
The size of the drives is why I'm a little hesitant to give Internet advice. A value of 280.86 for 60 Hz isn't an intuitively obvious value.
Have a look at the
PowerFlex 700H Programming Manual.
The PowerFlex 700H could be configured for speed-related parameters to all be in units of Hz or units of RPM. There's a parameter (Parameter 79, Speed Units) that automatically goes through and converts them all from Hz to RPM if you change that parameter. PLEASE don't mess with it, but it's worth looking at to see the value.
Then go to Page 24 and look at the diagram for Parameter 83, the Overspeed Limit. This shows you the relationship between Min Speed, Max Speed, Max Frequency, and Overspeed Limit.
PowerFlex 700H drives don't use engineering units on the network reference. Instead, the full range of the value sent from the PLC is a 16-bit signed integer.
So for most PowerFlex 700H drives, the value of 32767 in the network reference should give you the Max Frequency (Parameter 55).
You can look at that value directly in whatever tag is sent out to the drive, or indirectly as Parameter 272 (Drive Ref Result).
This is different from the PowerFlex 755 family drives, which use actual engineering units, where "30.0" would be 30.0 Hz. It's just speculation, but maybe your integrator copied some code or got confused between 750-family drives and the older 700-family.
So I guess my only really usable advice is... "be careful".