Phoenix Contact QUINT4-PS/12-24DC/24DC/1.3/SC Manual page 28

13.2.1 Redundancy operation
Redundant circuits are suitable for supplying systems and
system parts which place particularly high demands on
operational reliability.
If energy is to be supplied to the load with 1+1 redundancy,
two power supplies of the same type and performance class
must be used. In the event of an error, it must be ensured
that one of the power supplies is able to provide the total
required power for the load. This means that in redundancy
mode, two 1.3 A power supplies supply a load with a
nominal current of 1.3 A, for example. During normal
operation of the power supplies, each power supply
therefore supplies 0.65 A.
Always use cables with the same cross sections and lengths
when wiring the power supplies on the DC output side.
A redundancy module can be used to 100% decouple two
power supplies from one another and to ensure the supply.
A distinction is made here between passive and active
redundancy modules. Optimum decoupling with
simultaneous monitoring and minimal power dissipation can
be achieved with the UNO DIODE redundancy module.
Figure 25 Schematic diagram, redundant operation with
diode
I
N
+ −
+
−
Certain specifications apply in redundancy operation with
regard to the configuration of the keepout areas. In
redundancy operation, the power supplies are operated with
maximum half the nominal power. The keepout areas are
therefore reduced.
The following conditions must be met for 1+1 and n+1
redundancy operation of the power supplies in conjunction
with a UNO DIODE redundancy module.
Only use power supplies with the same performance class
and configuration for parallel connection.
Using the signaling settings, you can monitor whether both
power supplies are being operated with ≤ half the nominal
load. In the case of system extension, an overload is
prevented if one of the power supplies fails.
13.2.2 Increased power
When n power supplies are connected in parallel, the output
current is increased to n x I
110257_en_00
I
N
+ −
= I
Σ
N
+ −
. Parallel connection for
N
QUINT4-PS/12-24DC/24DC/1.3/SC
increased power is used when extending existing systems.
If the individual power supply does not cover the current
consumption of the most powerful load, parallel connection
of power supplies is recommended.
When three or more power supplies are
connected in parallel, each output must be
protected separately, e.g., by a circuit breaker or
decoupling module such as UNO DIODE or
STEP DIODE.
Figure 26 Schematic diagram of increased performance
I
N
+ –
+
–
I
N
+ –
IΣ= 2 x I
N
+ –
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