Vacon CX, Руководство пользователя

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Multi-purpose Control Application II Multi-purpose Control Application II Multi-purpose Control Application II Multi-purpose Control Application II Multi-purpose Control Application II
Vacon Plc
Phone: +358-(0)201 2121 Fax: +358-(0)201 212 205
Service: +358-40-8371 150 E-mail: vacon@vacon.com
Par. 7. 6
Par. 7. 7
I
T
f
par. 1. 7
I
UMCH7_91
Par. 7. 9
Overload area
Current
limit
The default value is set assuming that there is no external fan cooling the motor. If
an external fan is used this parameter can be set to 90% (or even higher).
The value is set as a percentage of the
motor name plate data, parameter 1
.....
13,
motor's nominal current, not the drive's
nominal output current. Motor's nominal
current is the current which the motor can
stand in direct on-line use without being
overheated.
If you change the parameter 1 ..... 13 this
parameter is automatically restored to the
default value.
Setting this parameter (or parameter 1 ..... 13)
does not affect to the maximum output current
of the drive. Parameter 1 ..... 7 alone determines
the maximum output current of the drive.
The motor thermal time is specific for the
motor design and it varies between different
motor manufacturers.
The default value for the time constant is
calculated basing on the motor name plate
data given with parameters 1
.....
12 and 1
.....
13. If
either of these parameters is set, this
parameter is set to default value.
If the motor's t
6
-time is known (given by the
motor manufacturer) the time constant
7. 8 7. 8 7. 8 7. 8 7. 8 Motor thermal protection, time constant Motor thermal protection, time constant Motor thermal protection, time constant Motor thermal protection, time constant Motor thermal protection, time constant
This time can be set between 0.5—300 minutes.
This is the thermal time constant of the motor.The bigger the motor the bigger
the time constant. The time constant is the time within which the calculated thermal
stage has reached 63% of its final value.
Figure 6-26 Motor thermal current
I
T
curve.
The current can be set between 10.0—150.0% x I
nMotor
. This parameter sets the
value for thermal current at zero frequency. Refer to figure 6-26.
7. 7 7. 7
7. 7 7. 7
7. 7 Motor thermal protection, zero frequency current Motor thermal protection, zero frequency current
Motor thermal protection, zero frequency current Motor thermal protection, zero frequency current
Motor thermal protection, zero frequency current
parameter could be set basing on t
6
-time.
As a rule of thumb, the motor thermal time
constant in minutes equals to 2xt
6
(t
6
in
seconds is the time a motor can safely
operate at six times the rated current). If the
drive is in stop stage the time constant is
internally increased to three times the set
parameter value. The cooling in the stop stage
is based on convection and the time constant
is increased.