Use Of Mm4 Input Chokes; Power Losses; Figure 10-18 Power Losses Micromaster 411 / Combimaster 411 - Siemens MICROMASTER 411 Operating Instructions Manual

10 Engineering Information
10.10

Use of MM4 Input Chokes

When the inverter is operating it gives rise to a non-sinusoidal current from the
mains supply with harmonics. The amplitude of the harmonics can be reduced by
fitting input chokes.
When the mains supply impedance is less then 1% it is necessary to use an input
choke with the inverter. It is recommended to use the standard MM4 range of input
chokes, details of which can be obtained from the DA51.2 Catalogue. The choke
must be housed in a mechanical enclosure appropriate to the environment.
10.10.1 Mains Supply Impedance
This is the ratio of the inverter rated power to mains short-circuit power. If the
mains supply impedance is below 1%, the lifetime of the electrolytic capacitors
could be reduced.
The mains short-circuit power may be obtained from the power supply company, or
may be read from the Type Plate of the supplying power transformer.
10.11

Power Losses

Figure 10-18 shows the power loss for the MICROMASTER 411/COMBIMASTER
411 Inverters.
98
%
96
94
92
90
88
0 5 10

Figure 10-18 Power Losses MICROMASTER 411 / COMBIMASTER 411

146
15 20 25 30
Output Frequency
MICROMASTER 411 & COMBIMASTER 411
35 40 45 50
Hz
Issue 03/01
Efficiency at Max Line CSB
Efficiency at Min Line CSB
Efficiency at Max Line CSC
Efficiency at Min Line CSC
Operating Instructions
6SE6400-5CA00-0BP0