QUINT-PS/24DC/24DC/ 5/CO
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14
SFB technology
SFB (Selective Fuse Breaking) technology reliably switches
off faulty current paths in the event of a short circuit. In this
case, it supplies up to six times the nominal current for 12
ms. SFB technology therefore reliably triggers standard
circuit breakers. Faults are located reliably and important
system parts remain in operation.
14.1
Circuit breaker tripping characteristics
Typically, a circuit breaker trips within 3 ... 5 ms. Fast
enough to avoid voltage drops of parallel connected loads.
Figure 9
Quick tripping of circuit breakers with SFB
technology
14.2
Installation notes
To use the SFB technology of the QUINT DC/DC converter,
you must observe the following requirements:
–
When designing the secondary side, consider the
configuration matrix that describes the maximum cable
lengths depending on the performance class of the DC/
DC converters, the conductor cross section, and the
circuit breaker.
–
Make sure that the source to be supplied is able to
deliver a corresponding current pulse to supply the DC/
DC converter. For
example, this can be achieved by
upstream connection of a QUINT SFB power supply
(see accessories) or suitable battery capacity.
–
Ensure the lowest possible cable impedance at the
input of the DC/DC converter by using short cable
lengths and large cable cross sections.
14.3
Deactivating SFB technology
The DC/DC converter is equipped with an additional SFB
switch which can be used to deactivate SFB technology.
The SFB switch is located on the top side of the housing and
is accessible for suitable tools, such as a small screwdriver
through the vents.
Figure 10
Position of the SFB switch
The current configuration matrix can be found
in the product download area.
Observe the maximum distance between the
source to be supplied and the DC/DC
converter.
(see also SFB configuration)
t
I [A]
6x I
N
I
BOOST
I
N
3-5 ms
If conditions cannot be observed, SFB
technology can be deactivated.
Switch position
SFB technology status
left
ON (default setting)
right
OFF
Activating/deactivating SFB technology must
only be performed when the DC/DC converter
is switched off.
QUINT PO
WER
+
-
Input D
C 24V
Ou
tpu
t DC
24
V
5 A
-
-
+
+
DC
OK
Ι<
Ι
N
DC OK
Boost
18-29.5 V
-
U >
IN
19.2V
U
<9.6V
IN
!
ON
OFF
SFB
