M-Family
DC-DC Converters <100 W
Rugged Environment
7 - 8
Edition 2/96 - Melcher AG
MELCHER
The Power Partners.
7.1
Input fuse
A fuse holder containing a slow-blow type fuse (Dimension:
5
× 20 mm) is mounted in the converter's back plate. The
fuse protects the module against severe defects. It may not
fully protect the module at input voltages exceeding
200 V DC. In applications where the converters operate at
DC source voltages above 200 V DC, an external fuse or a
circuit breaker at system level should be installed.
For applications where the fuse should be inaccessible:
see option F.
Input Under-/Overvoltage Cut-out
If the input voltage remains below 0.8
Ui min or exceeds
1.1
Ui max (approx. values), an internally generated inhibit
signal disables the output(s). When checking this function
the absolute maximum input voltage rating
Ui abs must be
carefully considered (see table "Input Data").
Inrush Current
The C...LM and C/D/LMZ (excluding FM) modules incorpo-
rate a NTC resistor in the input circuitry which (during the
initial switch-on cycle) limits the peak inrush current to
avoid damage to connectors and switching devices. Subse-
quent switch-on cycles within a short interval will cause an
increase of the peak inrush current due to the warming up
of the NTC resistor. Refer also to option E description.
Table 6: Fuse types (slow-blow)
Series
Schurter type
Part number
AM 1000...3000
SPT 10 A
250 V
0001.2514
BM 1000...3000
SPT 8 A
250 V
0001.2513
FM 1000...3000
SPT 5 A
250 V
0001.2511
CM/CMZ 1000...3000
SPT 3.15 A 250 V
0001.2509
DM/DMZ 1000...3000
SPT 2.5 A
250 V
0001.2508
EM 1000...3000
LM/LMZ 1000...3000
U
i DC
________
U
i min DC
2
345
6
1
0.10
1.00
10.00
AM
I
i [A]
LM/LMZ
BM
FM
CM/CMZ
DM/DMZ
EM
350
300
50; 250
40; 200
30; 150
20; 100
10;
50
0
400
0
0.8
2.0
1.0
2.5
1.2
3.0
1.4
3.5
1.6
4.0
0.6
1.5
0.4
1.0
0.2
0.5
AM
BM
CM/CMZ
FM
EM
A…EM
LM
Ii [A]
LM/LMZ
DM/DMZ
t [ms]
LM
A…FM
Fig. 3
Typical inrush current at initial switch-on cycle and at
Ui max [DC] versus time
Fig. 2
Typical input current versus relative input voltage at
nominal output load