Vacon Plc
Phone: +358-201 2121
Fax:+358-201 212 205
Service: +358-40-8371 150
E-mail: [email protected]
E-mail: [email protected]
Vacon
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Pump control with autochange
6. 8
Overvoltage controller
6. 9
Undervoltage controller
These parameters allow the over/undervoltage controllers to be switched out of
operation. This may be useful, for example, if the mains supply voltage varies more
than -15%—+10% and the application will not tolerate this over-/undervoltage, the
regulator controls output frequency according to the supply fluctuations.
Over/undervoltage trips may occur when controllers are switched out of operation.
7. 1
Response to the reference fault
0 = No response
1 = Warning
2 = Fault, stop mode after fault according to parameter 4.7
3 = Fault, stop mode after fault always by coasting
A warning or a fault action and message is generated if 4—20 mA reference signal
is used and the signal falls below 4 mA. The information can also be programmed
via digital output DO1 and via relay outputs RO1 and RO2.
7. 2
Response to external fault
0 = No response
1 = Warning
2 = Fault, stop mode after fault according to parameter 4.7
3 = Fault, stop mode after fault always by coasting
A warning or a fault action and message is generated from the external fault signal
in the digital input DIA3. The information can also be programmed into digital output
DO1 and into relay outputs RO1 and RO2.
7. 3
Phase supervision of the motor
0 = No action
2 = Fault
Phase supervision of the motor ensures that the motor phases have approximately
equal current.
7. 4
Earth fault protection
0 = No action
2 = Fault message
Earth fault protection ensures that the sum of the motor phase currents is zero.
The overcurrent protection is always working and protects the frequency converter
from earth faults with high currents.
Parameters 7. 5—7. 9 Motor thermal protection
General
Motor thermal protection is to protect the motor from overheating. Vacon CX/CXL/CXS drive is
capable of supplying higher than nominal current to the motor. If the load requires this high current
there is a risk that motor will be thermally overloaded. This is true especially at low frequencies.
With low frequencies the cooling effect of the motor is reduced and the capacity of the motor is
reduced. If the motor is equipped with an external fan the load reduction on low speeds is small.