Power SuppliesPower Supplies
DC-UPS Accupac with electronic charging controller
With transformer equipped power supplies are important
connecting links for the energy supply of electrical
control systems. The distribution transformer brings the high
line-voltage down to an usable secondary voltage level.
In reference to the requirements this voltage might be
converted into direct current (DC) by using rectifier units.
In dependence on the differential line voltages in several
countries, power supplies must be adapted on this circumstances.
The International Standard DIN IEC 38 has
been achieved in order to standardize for many countries
their main line voltage level. F E A S power supply units
are especially designed to cover the whole range of
different voltage levels. The scheduled realization of rearrangement
of international main line voltages is shown as
follows.
The centre piece of any dc power supply is the distribution
transformer. This transformer assured the isolation
between the primary and secondary voltages and supplies
the low voltage (max. 50Vac) which will be used to provide
the power for control circuits or rectifier units. To generate
a safety-low-voltage according to VDE 0551/EN 60742/
IEC 742 a special safety-transformer, equipped with separated
winding coils, is needed in any case. The test voltage
rate for this transformer should be 3,75 kV AC between the
primary and secondary windings. It is relevant, that during
this test an AC-voltage rate from min. 200V and max.450V
is applied on the input side.
Isolating transformers according to VDE 0550 are trans-
formers with reinforced isolation between the primary and
secondary windings.