KP Series
AC-DC Converters >100 Watt
Rugged Environment
Edition 4/4.99
4/23
MELCHER
The Power Partners.
Rs ext
Ri
RNTC
Iinr p
Ui rms
Ci
04001
Input Fuse
A fuse mounted inside the converter protects the module
against severe defects.
Table 3: Fuse Specication
Module
Fuse type
Fuse rating
LKP 5000 1
slow-blow
SP T
4 A, 250 V
1 Fuse size 5
× 20 mm
Input Under-/Overvoltage Lock-out
If the input voltage remains below approx. 110 V AC or ex-
ceeds approx. 280 V AC an internally generated inhibit sig-
nal disables the output(s). When checking this function the
absolute maximum input voltage rating
Ui abs should be
considered! Between
Ui min and the undervoltage lock-out
level the output voltage may be below the value defined in
table:
Output data (see: Technical Information: Measuring
and Testing).
Input Transient Protection
A VDR together with the input fuse and a symmetrical input
lter form an effective protection against high input tran-
sient voltages.
Fig. 2
Equivalent circuit diagram for input impedance
Electrical Input Data
General Conditions
–
TA = 25
°C, unless T
C is specied.
– Pin 18 connected to pin 14,
Uo adjusted to Uo nom (option P); R input not connected.
Table 2: Input data
Input
LKP
Characteristics
Conditions
min
typ
max
Unit
Ui
Operating input voltage
Io = 0…Io nom
187
255
3
Ui nom Nominal input voltage
TC min…TC max
230
Ii
Input current
Ui nom, Io nom 1
1.25
Arms
Pi o
No-load input power
Ui min…Ui max
710
W
Pi inh
Idle input power
unit inhibited
2
3
Ri
Input resistance
TC = 25°C
480
m
RNTC
NTC resistance 2
3200
4000
Ci
Input capacitance
52.8
66
79.2
F
Ui RFI
Conducted input RFI
EN 55022
B
Radiated input RFI
Ui nom, Io nom
B
Ui abs
Input voltage limits
–400
400
V DC
(without damage)
–400
400
VP
1 With double output modules, both outputs loaded with Io nom.
2 Initial switch-on cycle. Subsequent switch-on/off cycles increase the inrush current peak value.
3 AC frequency range 47...63 Hz.
Inrush Current Limitation
The modules of the versions -5, -6, -7 incorporate an NTC
resistor in the input circuitry which - at initial turn on - re-
duces the peak inrush current value by a factor of 5...10 to
protect connectors and switching devices from damage.
Subsequent switch-on cycles within short periods will
cause an increase of the peak inrush current value due to
the warming-up of the NTC resistor. See also:
E option.
Inrush Current Peak Value
The inrush current peak value (initial switch-on cycle) can
be determined by following calculation:
Ui rms
√2
Iinr p = ––––––––––––––––
(
Rs ext + Ri + RNTC)