Datasheet

CD10.482
CD-Series
DC/DC Converter 48V/48V, 5A, 240W
PRELIMINARY
22.2. OUTPUT CIRCUIT BREAKERS
Standard miniature circuit breakers (MCB’s or UL 1077 circuit breakers) are commonly used for AC-supply systems and
may also be used on 48V branches.
MCB’s are designed to protect wires and circuits. If the ampere value and the characteristics of the MCB are adapted to
the wire size that is used, the wiring is considered as thermally safe regardless of whether the MCB opens or not.
To avoid voltage dips and under-voltage situations in adjacent 24V branches which are supplied by the same source, a
fast (magnetic) tripping of the MCB is desired. A quick shutdown within 10ms is necessary corresponding roughly to
the ride-through time of PLC's. This requires power supplies with high current reserves and large output capacitors.
Furthermore, the impedance of the faulty branch must be sufficiently small in order for the current to actually flow.
The best current reserve in the power supply does not help if Ohm’s law does not permit current flow. The following
table has typical test results showing which B- and C-Characteristic MCBs magnetically trip depending on the wire cross
section and wire length.
The following test results indicate the maximal wire length for a magnetic (fast) tripping. The wire length is always
two times the distance to the load (+ and – wire).
Fig. 22-3 Test circuit for maximum wire length
Test results for maximum wire length:
0.75mm² 1.0mm² 1.5mm² 2.5mm²
C-2A
43m 54m 82m 117m
C-3A
21m 28m 41m 66m
C-4A
9m 11m 15m 23m
C-6A
3m 3m 4m 6m
B-6A
11m 13m 20m 30m
MCB
DC/DC
Converter
DC
DC
+
-
+
-
Load
Wire length
S1... Fault simulation switch
S1
B-10A
2m 2m 3m 4m
22.3. CHARGING OF BATTERIES
The device can be used to charge lead-acid or maintenance free batteries. Four 12V SLA or VLRA batteries are needed
in series connection.
Instructions for charging batteries:
a) Ensure that the ambient temperature of the Device is below 45°C.
b) Set output voltage, measured at no load and at the battery end of the cable, very precisely to the end-of-charge
voltage.
End-of-charge voltage 55.6V 55.0V 54.3V 53.6V
Battery temperature 10°C 20°C 30°C 40°C
c) Use a 10A circuit breaker or blocking diode between the Device and the battery.
d) Ensure that the output current of the Device is below the allowed charging current of the battery.
e) Use only matched batteries when putting 12V types in series.
f) The return current to the Device (battery discharge current) is typ. 6mA when the Device is switched off (except in
case a blocking diode is utilized).
g) Do not use the devices for battery charging in mounting orientations other than the standard mounting
orientation or in any other condition where a reduction of the output current is required (e.g. altitude).
July 2018 / Rev. 0.1 DS-CD10.482-EN All values are typical figures specified at 48Vdc input voltage 48V, 5A output load,
25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone [phone] Germany
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