Siemens MICROMASTER 420 Reference Manual

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MICROMASTER 420 Reference Manual
Issue A1
5
2 Engineering Information
This chapter contains Information to assist the user in using the
MICROMASTER 420 in the most efficient way.
Topics include connection details, derating factors and methods of protecting the
motor and inverter.
Examples are given to illustrate the use of the parameter list.
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2.1 Current Limit and Overload Operation ......................................................................8
2.1.1 Current Monitoring Accuracy.....................................................................................9
2.2 Fast Current Limit......................................................................................................9
2.3 Positive Temperature Coefficient Resistor Use.......................................................10
2.4 I
2
t Performance........................................................................................................10
2.5 Internal Overtemperature ........................................................................................10
2.6 Overvoltage and Trip Levels....................................................................................11
2.7 Boost........................................................................................................................11
2.8 Proportional and Integral Control (PI)......................................................................12
2.8.1 What is Closed Loop control?..................................................................................12
2.8.2 Implementation on MICROMASTER 420................................................................12
2.8.3 Setting up the PI controller ......................................................................................12
2.8.4 PI Setpoint ramp times ............................................................................................14
2.8.5 PI Controller Proportional and Integral terms..........................................................14
2.8.6 Ziegler-Nichols method of Optimisation ..................................................................16
2.8.7 PI output limits .........................................................................................................18
2.8.8 Further features .......................................................................................................18
2.9 Braking.....................................................................................................................20
2.9.1 Normal Braking........................................................................................................20
2.9.2 DC Braking ..............................................................................................................20
2.9.3 Vdc Max Controller..................................................................................................21
2.9.4 Compound Braking..................................................................................................21
2.10 Derating Factors......................................................................................................22
2.10.1 Derating with Temperature......................................................................................22
2.10.2 Operation with Long Cables ....................................................................................22
2.10.3 Derating with Altitude...............................................................................................24
2.10.4 Derating with Switching Frequency.........................................................................24
2.10.5 Derating for Sideways Installation...........................................................................25

Siemens MICROMASTER 420 Specifications

General

Power Range	0.12 kW to 11 kW
Output Voltage	0 to input voltage
Input Frequency	47 Hz to 63 Hz
Output Frequency	0 Hz to 650 Hz
Overload Capacity	150% for 60 seconds
Enclosure Rating	IP20
Input Voltage	200 V to 240 V (±10%), 380 V to 480 V (±10%)
Control Type	V/f control
Braking	Optional braking module
Protection Features	Overcurrent, overvoltage, undervoltage, overload, short circuit, ground fault
Cooling	Air-cooled
Ambient Temperature	-10 °C to +50 °C
Communication Interfaces	USS protocol