Introduction; Variant Dependent Options; Filters - Siemens MICROMASTER 420 Reference Manual

4.1

Introduction

Several options are available for use with Siemens Standard inverters. These are
intended to assist product selection, installation and commissioning in certain
applications.
4.2

Variant Dependent Options

4.2.1

Filters

MICROMASTER 420 inverters are designed to minimize conducted and radiated
interference. However, they are power electronic products and generate significant
levels of interference over a wide electromagnetic spectrum.
In many applications it is possible to operate without filters or with the built in filter
only. However, in order to achieve higher levels of attenuation an external filter
may be required. In particular, an external filter will be needed to meet residential,
commercial and light industrial levels.
The purpose of RFI filters is to reduce the conducted levels of interference from the
inverter to the supply. It is not intended to reduce radiated interference or
attenuate interference into the inverter. The filter should be fitted to the mains
input to the inverter and will be damaged if installed in the inverter output.
The filters are designed to mount underneath the inverter to minimize space
requirements. Units are also available with built in filters.
Detailed installation drawings are contained in the CD-ROM supplied with the
inverter.
Figure 4-1
66
MAINS INPUT
FILTERED OUTPUT
Inverter with Filter.
FILTER
MICROMASTER 420 Reference Manual
Issue A1