Functions, monitoring, and protective functions
9.3 Drive functions
Drive converter cabinet units
334
Operating Instructions, 07/07, A5E00288214A
9.3.12
Unit changeover
Description
Parameters and process variables for input and output can be switched to a suitable units
system (SI units, US units or referenced variables (%)) with the help of the unit changeover
function.
The following constraints apply to the unit changeover:
●
Unit changeover is only possible for the "VECTOR" and "A_INF" drive object.
●
Type plate parameters of the converter and/or motor can be switched between SI and US
units but not to referenced values.
●
Once the changeover parameters have been switched, all parameters assigned to a
group of dependent units are switched to the new unit together.
●
A separate parameter is available for selecting technological units (p0595) for the
representation of technological variables in the technology controller.
●
If a changeover is made to referenced variables and the reference variable is
subsequently changed, the % value entered in a parameter will not change.
Example:
–
A fixed speed of 80% corresponds, for a reference speed of 1500 rpm, to a value of
1200 rpm.
–
If the reference speed is changed to 3000 rpm, the value of 80% is retained and is
now 2400 rpm.
Constraints
●
When a unit changeover occurs, rounding to the decimal places is carried out. This can
mean that the original value might change by up to one decimal place.
●
If a referenced form is selected and the reference parameters (e.g. p2000) are changed
retrospectively, the referenced values of some of the control parameters are also
adjusted to ensure that the control behavior is unaffected.
●
Changing the reference variables (p2000 to p2007) in the STARTER in offline mode can
cause parameter value limit violations, leading in turn to error messages when the values
are loaded to the drive unit.
