Examining The Compatibility Of The Motor And Drive; Protecting The Motor Insulation And Bearings - ABB ACS880-07 Hardware Manual

66 Guidelines for planning the electrical installation

Examining the compatibility of the motor and drive

Use an asynchronous AC induction motor, permanent magnet synchronous motor, AC
induction servomotor or ABB synchronous reluctance motor (SynRM motor) with the drive.
Several induction motors can be connected to the drive at a time.
Select the motor size and drive type from to the rating tables in chapter
basis of the AC line voltage and motor load. Use the DriveSize PC tool if you need to tune
the selection more in detail.
Make sure that the motor withstands the maximum peak voltage in the motor terminals.
See the Requirements table
bearings in drive systems, refer to section
below.
Note:
•
Consult the motor manufacturer before using a motor whose nominal voltage differs
from the AC line voltage connected to the drive input.
•
The voltage peaks at the motor terminals are relative to the supply voltage of the drive,
not the drive output voltage.
•
If the motor and drive are not of the same size, consider the following operation limits
of the drive control program:
•
motor nominal voltage range 1/6 ... 2 · U
•
motor nominal current range 1/6 ... 2 · I
in scalar control. The control mode is selected by a drive parameter.

Protecting the motor insulation and bearings


The drive employs modern IGBT inverter technology. Regardless of frequency, the drive
output comprises pulses of approximately the drive DC bus voltage with a very short rise
time. The pulse voltage can almost double at the motor terminals, depending on the
attenuation and reflection properties of the motor cable and the terminals. This can cause
additional stress on the motor and motor cable insulation.
Modern variable speed drives with their fast rising voltage pulses and high switching
frequencies can generate current pulses that flow through the motor bearings. This can
gradually erode the bearing races and rolling elements.
Optional du/dt filters protect motor insulation system and reduce bearing currents.
Optional common mode filters mainly reduce bearing currents. Insulated N-end (non-drive
end) bearings protect the motor bearings.
on page 67. For basics of protecting the motor insulation and
Protecting the motor insulation and bearings
N
N
of the drive in DTC control and 0 ... 2 · I
Technical data on
N