6.7.1
Unit changeover
Description
Using the unit switchover function, you can switch over parameters and process variables for
input and output to an appropriate system of units: US units, SI units or relative variables as
a %.
Independent of this, you can define the units for process variables or change over to
percentage values.
The following options are available:
●
●
●
The motor standard, the unit system as well as the process variables can only be changed
with STARTER or Startdrive offline.
Restrictions for the unit changeover function
● The values on the rating plate of the inverter or motor cannot be displayed as percentage
values.
● Using the unit changeover function several times (for example, percent → physical unit 1
→ physical unit 2 → percent) may lead to the original value being changed by one decimal
place as a result of rounding errors.
● If the unit is changed over into percent and the reference value is then changed, the
percentage values relate to the new reference value.
Example:
– For a reference speed of 1500 rpm, a fixed speed of 80% corresponds to a speed of
– If the reference speed is changed to 3000 rpm, then the value of 80% is kept and now
Reference variables for unit changeover
p2000 Reference frequency/speed
p2001 Reference voltage
p2002 Reference current
p2003 Reference torque
r2004 Reference power
p2005 Reference angle
p2006 Reference temperature
p2007 Reference acceleration
Converter with CU250S-2 Control Unit
Operating Instructions, 01/2016, FW V4.7 SP6, A5E31759476B AE
Changing over the motor standard (Page 266) IEC/NEMA
Changing over the unit system (Page 267)
Changing over process variables for the technology controller (Page 267)
1200 rpm.
means 2400 rpm.
Advanced commissioning
6.7 Application-specific functions
265