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Retrofitting an old current converter by implementing
SINAMICS DCM:
When retrofitting an old current converter in a B6C / (B6)A(B6)C connection (for other
types/circuit types please consult us) with 6RA80, the following procedure is possible:
Replace the converter and insert the new semi-conductor fuses prescribed for 6RA80. Other
existing components such as the converter transformer or an existing commutation reactor
and overvoltage protection can be kept. Any existing smoothing reactor in the direct current
circuit should also be kept.
As the old converters did not usually include a closed-loop controlled field device, which
made a commutation reactor superfluous, a commutation reactor must be retrofitted for the
field circuit if the field supply is used in 6RA80. Its rated alternating current should be equal
to the rated current of the motor field; if this is not known, dimension it for the rated current of
the field power supply unit.
New 6RA80 converters emit no higher radio interference than older products used
previously, which means it is not necessary to retrofit the interference suppression filter when
retroftting with 6RA80, as long as the plant operator does not make higher demands than for
the old device.
Selection of replacement converter see here:
http://support.automation.siemens.com/WW/view/en/26117006