YASKAWA CR700

65
YASKAWA AC Drive
CR700
Catalog
｜
KAEP C710617 24
｜
YASKA WA
Notes on Motor Operation
■
Motor Bearing Life
In applications involving constant speed over long
periods, the life of the motor bearing may be shortened.
This is called bearing electrolytic corrosion.
The installation of a zero
-
phase reactor between the
drive and motor, and the utilization of a motor with
insulated bearings are effective countermeasures. Details
can be found in the technical documentation. Contact
your Yaskawa or nearest sales representative for more
information.
Using a Standard Motor
■
Low Speed Range
There is a greater amount of
loss when operating a motor
using an drive than when
running directly from line
power. With a drive, the motor
can become quite hot due to
the poor ability to cool the
motor at low speeds. The load
torque should be reduced
accordingly at low speeds.
The  gure above shows the allowable load characteristics
for a Yaskawa standard motor. A motor designed
speci cally for operation with a drive should be used
when
100% continuous torque is needed at low speeds.
■
Insulation Tolerance
Consider voltage tolerance levels and insulation in
applications with an input voltage of over
440 V or
particularly long wiring distances. Use a drive motor that
has been equipped with isolation countermeasures.
■
High Speed Operation
Problems may occur with the motor bearings and
dynamic balance in applications operating at over
60 Hz.
Contact Yaskawa for consultation.
■
Torque Characteristics
Torque characteristics differ when operating directly from
line power. The user should have a full understanding of
the load torque characteristics for the application.
■
Vibration and Shock
The motor may generate vibrations in the following
circumstances.
(
1
)
Resonance
Take particular caution when using a variable speed
drive for an application that is conventionally run
from line power at a constant speed. Shock
-
absorbing rubber should be installed around the
base of the motor and the Jump Frequency
selection should be enabled to prevent resonance.
(
2
)
Any imperfection on a rotating body increases
vibration with speed.
Caution should be taken when operating above the
motor rated speed.
(
3
)
Subsynchronous Resonance
Subsynchronous resonance may occur in applications
with high load inertia, as well as in motors with a
relatively long shaft. Yaskawa recommends using
Closed Loop Vector Control for such applications.
■
Audible Noise
Noise created during run varies by the carrier frequency
setting. Using a high carrier frequency creates about as
much noise as running from line power. Operating above
the rated speed
(
i.e., above
60 Hz
)
, however, can create
unpleasant motor noise.
Using a Highly Ef cient Motor
■
IE3 Motor
The IE
3 motor has superior features compared to the
standard IE
1 motors. Contact Yaskawa for technical
documents.
50
36
20 60
60
70
80
90
100
25% ED
(
or 15 min.
)
40% ED
(
or 20 min.
)
60% ED
(
or 40 min.
)
Allowable Load Characteristics
for a Yaskawa Motor
Frequency
(
Hz
)
Continuous operation
Torque
(
%
)
Features
Catalog Code /
Selecting the Capacity
Basic
Instructions
Standard
Speci cations
Standard
Connection Diagram
Terminal
Speci cations
Dimensions
Fully
-
Enclosed
Design
Peripheral Devices
and Options
Global Service
Network
Application
Notes