ML120.244
MiniLine-2
24V,
5A,
S
INGLE
P
HASE
I
NPUT
22.
A
PPLICATION
N
OTES
22.1.
P
EAK
C
URRENT
C
APABILITY
The power supply can deliver peak currents up to several milliseconds.
This helps to start current demanding loads. Loads such as solenoids, contactors and pneumatic modules often have a
steady state coil and a pick-up coil. The inrush current demand of the pick-up coil is several times higher than the
steady-state current and usually exceeds the nominal output current. The same situation applies when starting a
capacitive load.
The peak current capability also ensures the safe operation of subsequent circuit breakers of load circuits. The load
branches are often individually protected with circuit breakers or fuses. In case of a short or an overload in one branch
circuit, the fuse or circuit breaker need a certain amount of over-current to open in a timely manner. This avoids
voltage loss in adjacent circuits.
The extra current (peak current) is supplied by the power converter and the built-in large sized output capacitors of
the power supply. The capacitors get discharged during such an event, which causes a voltage dip on the output. The
following two examples show typical voltage dips:
Fig. 22-1
Peak loading with 2x the nominal
current for 50ms, typ.
Fig. 22-2
Peak loading with 5x the nominal
current for 5ms, typ.
10ms/DIV
Output
Voltage
Output
Current
24.5V
0A
10A
16V
1ms/DIV
Ou
tpu
t
Vol
tag
e
Output
Current
24.5V
0A
25A
10.5V
Peak load 10A (resistive load) for 50ms
Output voltage dips from 24V to 16V.
Peak load 25A (resistive load) for 5ms
Output voltage dips from 24V to 10.5V.
Peak current voltage dips
typ.
from 24V to 16V
at 10A for 50ms, resistive load
typ.
from 24V to 16V
at 25A for 2ms, resistive load
typ.
from 24V to 10.5V
at 25A for 5ms, resistive load
22.2.
B
ACK
-
FEEDING
L
OADS
Loads such as decelerating motors and inductors can feed voltage back to the power supply. This feature is also called
return voltage immunity or resistance against Back- E.M.F. (Electro Magnetic Force).
This power supply is resistant and does not show malfunctioning when a load feeds back voltage to the power supply.
It does not matter whether the power supply is on or off.
The maximum allowed feed-back-voltage is 35Vdc. The absorbing energy can be calculated according to the built-in
large sized output capacitor which is specified in chapter 6.
Apr. 2013 / Rev. 1.1 DS-ML120.244-EN
All parameters are specified at 24V, 5A, 230Vac input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany
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