QUINT-PS/24DC/24DC/ 5/CO
105537_en_02
PHOENIX CONTACT
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17
Operating modes
17.1
Series operation
Two DC/DC converters can be connected in series to
double the voltage. Only devices of the same performance
class should be connected in series. Series connection
should always be used if the output voltage of the module is
not sufficient. For example, DC/DC converters with 24
V
DC
nominal output voltage each supply 48
V
DC in series.
Depending on the specification of the PE connection, output
voltages of +48
V or -48
V as well as ±24
V DC can also be
made available.
Figure 13
Series operation
17.2
Parallel operation
DC/DC converters of the same type can be connected in
parallel to increase both redundancy and power. No further
adjustments to the default setting are necessary.
To ensure symmetrical load distribution, it is recommended
that all cable connections from the DC/DC converters to the
busbar are the same length and have the same conductor
cross section.
Depending on the system, a protective circuit should be
installed at each individual device output (e.g. decoupling
diode or DC fuse) for parallel connection of more than two
DC/DC converters. This prevents high return currents in the
event of a secondary device fault.
17.3
Redundant operation
Redundant circuits are suitable for supplying systems,
which place particularly high demands on operational
safety. If a fault occurs in the primary circuit of the first power
supply unit, the second device automatically takes over the
complete power supply without interruption, and vice versa.
For this purpose, the power supply units to be connected in
parallel must be large enough to ensure that the total current
requirements of all loads can be fully met by one power
supply unit. External decoupling diodes are required for
100% redundancy!
Optimization of redundancy can be achieved by decoupling
and monitoring. Phoenix Contact offers a comprehensive
product range for this purpose (e.
g., QUINT-DIODE or
QUINT-ORING).
Example: diode module
Example: QUINT ORING
+48 V
-48 V
+24 V
-24 V
+
-
+
-
+
-
+
-
+
-
+
-
+
I
N
−
+
I
N
−
+
+
−
−
Σ
=
I
N
+
I
N
−
+
I
N
−
+
+
−
−
Σ
= I
N
+
I
N
−
+
I
N
−
+
+
−
−
Σ
= I
N
