Siemens A1 Manual De Usuario
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MICROMASTER Applications Handbook
9.3
Braking Modules and Braking Resistors
During regeneration (see section 8.2.2) it may be necessary to dissipate the
energy that is returned to the inverter. MICROMASTER MM420 units do not have
the capability to dissipate regenerated energy.
energy that is returned to the inverter. MICROMASTER MM420 units do not have
the capability to dissipate regenerated energy.
Some Siemens inverters have a built in ‘braking chopper’ and require only an
external resistor to allow controlled dissipation. The resistors can be supplied as
optional parts to the inverters, and fit alongside the inverters. They are specially
designed to operate with the high voltages present in the DC link, and are of
metalclad, IP54 design. Braking resistors for operation with earlier
MICROMASTERs were designed to mount underneath the inverters. Other
resistors can also be used, but care must be taken to ensure they are of adequate
voltage and power rating.
external resistor to allow controlled dissipation. The resistors can be supplied as
optional parts to the inverters, and fit alongside the inverters. They are specially
designed to operate with the high voltages present in the DC link, and are of
metalclad, IP54 design. Braking resistors for operation with earlier
MICROMASTERs were designed to mount underneath the inverters. Other
resistors can also be used, but care must be taken to ensure they are of adequate
voltage and power rating.
9.4 EMC
Filters
MICROMASTER 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.
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.
However, in order to achieve higher levels of attenuation an external filter may be
required. In particular, an external filter will be needed in order to meet residential,
commercial and light industrial levels.
However, in order to achieve higher levels of attenuation an external filter may be
required. In particular, an external filter will be needed in order to meet residential,
commercial and light industrial levels.
The purpose of EMC 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. It should be fitted to the input supply to the
inverter and will be damaged if installed in the inverter output.
the inverter to the supply. It is not intended to reduce radiated interference or
attenuate interference into the inverter. It should be fitted to the input supply to the
inverter and will be damaged if installed in the inverter output.
The filters are designed to mount underneath the MICROMASTER to minimize
space requirements. Full installation instructions and information concerning the
appropriate filters are given in the Reference Manual.
space requirements. Full installation instructions and information concerning the
appropriate filters are given in the Reference Manual.
9.5 PROFIBUS
Module
Siemens Standard Drives incorporate an RS485 serial interface as standard. In
order to operate on a PROFIBUS system a separate conversion module is
required. The PROFIBUS module and the PROFIBUS system is described in
section 8.4.2.
order to operate on a PROFIBUS system a separate conversion module is
required. The PROFIBUS module and the PROFIBUS system is described in
section 8.4.2.
9.6
Input and Output Chokes
Chokes can be fitted to the input of the inverter to reduce harmonic distortion and
to reduce the effect of supply disturbance on the inverter. Chokes are also
recommended where supply impedance is less than 1%.
to reduce the effect of supply disturbance on the inverter. Chokes are also
recommended where supply impedance is less than 1%.
Chokes are fitted to the output of the inverter to allow operation with long cables.
The choke compensates for the stray capacitance of the cables. Recommended
chokes for different cable lengths and inverters are available.
The choke compensates for the stray capacitance of the cables. Recommended
chokes for different cable lengths and inverters are available.