Siemens MICROMASTER 420 - Functions

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MICROMASTER 420 Reference Manual
Issue A1
27
2.13
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Operation from Unearthed Supplies
The MICROMASTER 420 can be used on unearthed input supplies. In order to do
this it is necessary to remove the Y Caps (See Appendix D in the Operating
Instructions), and also to fit an output choke. (See Chapter 4, Options or choose
the Options category on the CD-ROM supplied with the inverter.) If a fault
condition occurs on the input of the inverter, the inverter will continue to function
and if there is an earth fault on one output phase, the inverter will continue to
operate. If there are two or more earth faults on the inverter output, the inverter will
trip on overcurrent F0001.
It is recommended that an external earth fault detection device be used to warn the
user when a fault condition has occurred so that the condition can be rectified
before it happens again. This will allow an uninterrupted operation.
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Connection of a 400 V 3-phase supply to a single phase or 3-phase 230 V
inverter will destroy the inverter.
2.14
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Multi-Motor Connection
Will follow with next version of Reference Manual.
2.15
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Control Modes (P1300)
Expand this section with graphics and method.
The various modes of operation of the MICROMASTER 420 control the
relationship between the speed of the motor and the voltage supplied by the
inverter. There are four modes of operation:
2.15.1 Linear V/f Control
Can be used for variable and constant torque applications, such as conveyors and
pumps.
2.15.2 Flux Current Control (FCC)
This control mode can be used to improve the efficiency and dynamic response of
the motor.
2.15.3 Quadratic V/f Control
This mode can be used for variable torque loads, such as fans and pumps.
2.15.4 Multi-point V/f Control
Expert mode only.