28/78 SUREWAVE SFC USER MANUAL
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Specifying transformer
The SureWave SFC requires a TN network. The most common and recommended transformer
configuration is using an output transformer with DYN11 vector group, and the SFC with input
RFI grounded. This gives the SFC a solid ground reference where no additional earth fault detec-
tion is required, and also allows single phase loads to utilize the converted power.
In general, there is nothing special about the SureWave SFC transformers, except for an EMC
screen (shielding); any quality transformer manufacturer will be able to provide a suitable solu-
tion. Please see ABB document 2UCD030000E003 for more detailed information.
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Sizing Transformers
When specifying a transformer, the engineering application team must be aware and take in to
account the required power output of the SureWave SFC. If an input transformer is being used
allowance must be made for the converter losses which will be around 4%. If both an input and
output transformer is employed, allowance must also be made for the additional losses of the
additional transformer.
If using an output transformer allowance must be made for internal transformer losses. Also, be
aware the rated power is rated at the SureWave SFC output terminals, not after transformer
losses.
