QT40.241 Datasheet, PDF (26/29 Pages) PULS GmbH – THREE PHASE INPUT

Q-Series
QT40.241, QT40.242
24V, 40A, THREE PHASE INPUT
24.5. CHARGING OF BATTERIES
The power supply can be used to charge lead-acid or maintenance free batteries. (Two 12V batteries in series)
Instructions for charging batteries:
a) 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
27.8V
27.5V
27.15V
26.8V
Battery temperature
10°C
20°C
30°C
40°C
b) Use a 50A or 63A circuit breaker (or blocking diode) between the power supply and the battery.
c) Ensure that the output current of the power supply is below the allowed charging current of the battery.
d) Use only matched batteries when putting 12V types in series.
e) The return current to the power supply (battery discharge current) is typ. 35mA when the power supply is
switched off (except in case a blocking diode is utilized).
24.6. OUTPUT CIRCUIT BREAKERS
Standard miniature circuit breakers (MCB’s or UL1077 circuit breakers) are commonly used for AC-supply systems and
may also be used on DC 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.
Fig. 24-9 Test circuit
Maximal wire length^*) for a fast (magnetic) tripping:
0.75mm² 1.0mm² 1.5mm² 2.5mm²
C-2A
28m
38m
54m
78m
C-3A
26m
35m
50m
74m
Power Supply MCB
AC
+
Load
+
C-4A
C-6A
C-8A
19m
12m
9m
26m
38m
58m
16m
24m
32m
12m
17m
25m
Wire length
DC ^-
S1... Fault simulation switch
S1
-
C-10A
7m
C-13A
4m
B-6A
19m
B-10A
11m
10m
15m
21m
5m
7m
11m
26m
35m
59m
17m
26m
37m
B-13A
10m
13m
21m
32m
B-16A
8m
11m
14m
24m
B-20A
4m
6m
8m
14m
*) Don’t forget to consider twice the distance to the load (or cable length) when calculating the total wire length (+ and – wire).
Dec. 2016 / Rev. 2.4 DS-QT40.241-EN
All parameters are specified at 24V, 40A, 3x400Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone [phone] Germany
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