Vacon Plc
Phone: +358-201 2121
Fax:+358-201 212 205
Service: +358-40-8371 150
E-mail: [email protected]
Page 42
Vacon
Pump and fan control with autochange
torque of the motor. The motor's name plate data,
parameter 1
.
13, the motor's nominal current and
the drive's nominal current I
CT
are used to find the
scaling ratio for the internal torque value. If other
than nominal motor is used with the drive the
accuracy of the torque calculation is decreased.
7. 14
Underload protection
Operation:
0 = Not in use
1 = Warning
2 = Fault
Tripping and warning will display the same message code. If tripping is set active
the drive will stop and activate the fault stage.
Deactivating the protection, by setting parameter to 0, will reset the underload time
counter to zero.
7. 15
Underload protection, field weakening area load
The torque limit can be set
between 20.0—150 % x T
nMotor
.
This parameter gives the value for
the minimum allowed torque when
the output frequency is above the
field weakening point.
Refer to the figure 6-23.
If parameter 1
.
13 is adjusted, this
parameter is automatically
restored to the default value.
Figure 6-23
Setting of minimum load.
7. 16
Underload protection, zero frequency load
The torque limit can be set between 10.0—150 % x T
nMotor
.
This parameter gives value for the minimum allowed torque with zero frequency.
Refer to the figure 6-23. If parameter 1
.
13 is adjusted, this parameter is automatically
restored to the default value.
7. 17
Underload time
This time can be set between 2.0—600.0 s.
This is the maximum allowed time for an underload state. There is an internal up/
down counter to accumulate the underload time. Refer to the figure 6-24.
If the underload counter value goes above this limit the protection will cause a trip
(refer to the parameter 7
.
14). If the drive is stopped the underload counter is reseted
to zero.
Par. 7
.
15
UMCH7_15
Par. 7
.
16
f
5 Hz
Underload area
Torque
Fieldweakening
point par. 6
.
3
