Rugged Environment
AC-DC Converters >100 Watt
T Series
500 Watt AC-DC Converters
Input to output isolation
Single output
• Universal AC input range
• DC output voltage for 24 and 48 V loads
• Battery charging for 24, 36, 48 V batteries with re-
mote temperature control
• Telecom rectifier applications
• Immune to transients and disturbances according to
VDE 160 and IEC/EN 61000-4-2,-3,-4,-5,-6
• 4000 V AC input to output electric strength test
• Very high efficiency, typically 93%
• Power factor
>0.96,
harmonics
<IEC/EN
61000-3-2,
low RFI
• No inrush current, hot plug-in capability
• High power density, 210 W/dm
3
, rugged mechanical
design
• Very compact 19" cassette (28 TE, 3 U, 160 mm),
Safety according to IEC/EN 60950
LGA
C
T Series
111
4.4"
3U
141
5.6"
28 TE
168
6.6"
Summary
The T series of converters are electrically isolated AC-DC
converters with an output power of up to 550 W. For higher
power requirements several units may be connected in
parallel.
The input of the T units is ideally adapted to the mains: Full
power factor correction, no inrush current, low RFI level and
high transient and surge immunity are key design features.
The T units behave similar to a resistive load.
The L-input provides a universal AC-input range from
85...255 V AC. It is the preferred type for 230 V mains,
whereas the U-input range is optimized for 110/120 V
mains. The output delivers an electrically isolated Safety
Extra Low Voltage (SELV) and is short-circuit and no-load
proof. Depending on the type, two output characteristics
are available, intended either for rectifier applications or for
battery charging purposes.
The latter types can be integrated into systems where the
output voltage is backed-up by batteries. The float charge
of the battery can be set by a cell voltage selector switch
according to the battery type used. Moreover these units
feature a temperature sensor input to improve the life ex-
pectancy of the battery.
The rectifier types suit for DC-bus applications at constant
voltage. As the output voltage is SELV, even electrically non
isolated switching regulators such as the Melcher PSR
types may be connected to the T output.
The T 1701 types are especially optimized to build distrib-
uted power systems together with the Melcher CQ-series
DC-DC converters as the signalling capabilities of both
families are matched. Distributed power systems have as
one advantage less power loss over load lines and fewer
regulation problems.
Melcher offers also backplanes for fast and simple set-up of
19" rack systems with T units (see chapter:
Back Planes).
Table of Contents
Page
Page
Functional Features ....................................................... 16
Auxilliary Functions ........................................................ 21
Electromagnetic Compatibility (EMC) ............................ 25
Immunity to Environmental Conditions ........................... 26
Environmental Conditions .............................................. 27
Mechanical Data ............................................................ 28
Safety and Installation Instructions ................................ 30
Description of Options .................................................... 33
Accessories .................................................................... 33
Summary .......................................................................... 1
Type Survey and Key Data .............................................. 2
Type Key .......................................................................... 2
Sensor Type Key .............................................................. 3
Functional Description ...................................................... 4
Electrical Input Data ......................................................... 5
Electrical Output Data of the Rectifier Version ................. 7
Electrical Output Data of Battery Charger Version ......... 10
Control Features of the Battery Charger Version ........... 12
Temperature Sensors ..................................................... 15
MELCHER
The Power Partners.
Edition 4/4.99
1/33
T Series
Type Survey and Key Data
AC-DC Converters >100 Watt
Rugged Environment
Table 1: Type Survey (All typical values at 20
°
C)
Output voltage
Output current
Input voltage range and efficiency
Options
U
o set
at
U
i nom
,
1
/
2
I
o nom
[V DC]
24.25
25.25...27.25...28.25
54.5
48
50.5...54.5...56.5
37.9...40.9...42.4
1
2
3
4
5
6
I
o nom
[A]
16
14.5
10
11
10
11
U
i min
...U
i max
70...140 V AC
UT 1201-7
2, 4
UT 1240-7Z
4, 3
UT 1701-7
5
–
UT 1740-7Z
5, 3
–
η
min 1
[%]
91
91
92
–
92
–
U
i min
...U
i max
85...255 V AC
LT 1201-7
2, 6
LT 1240-7Z
6, 3
LT 1701-7
6
LT 1702-7
2, 6
LT 1740-7Z
6, 3
LT 1840-7Z
3, 6
η
min 1
[%]
91
92
93
93
93
91
D
B1
Efficiency measured at
U
i nom
and
I
o nom
.
Instead of output power limitation, output current limitation.
Output voltage range controlled by input
U
cr
, remote temperature sensor and cell voltage selector switch.
Reduced output power for
U
i
= 70...95 V AC. See
Output Power Limitation.
Reduced output power for
U
i
= 70...100 V AC. See
Output Power Limitation.
Reduced output power for
U
i
= 85...155 V AC. See
Output Power Limitation.
Type Key
Type Key
Input voltage range
U
i
70...140 V, 47...63 Hz ................................ U
85...255 V, 47...63 Hz ................................. L
Series ............................................................................... T
Number of outputs: ........................................................... 1
Output
U
o set
24, 27.25 V .................................................. 2
48, 54.5 V .................................................... 7
40.9 V .......................................................... 8
Recifier version .................................... 01, 02
Battery charger version .............................. 40
Other voltages .................................... 00...99
Ambient temperature range
T
A
–25...71°C .................................................. -7
Customer specific ................................ -0...-6
Auxiliary functions and options
Remote bus voltage monitoring (option) ..... D
Cell voltage selector switch ......................... Z
Input fuse externally accessible ................... F
Baseplate (option) ...................................... B1
1
See
2
L T 1 7 40 -7 D Z F B1
3
4
1
2
also:
Description of Options
as well as data sheet:
Back Planes for the T Series.
Only for T 1240/1740/1840
3
No input for remote temperature sensor
4
With input for remote temperature sensor
Example:
LT 1740-7Z: AC-DC converter, input voltage range 85...255 V
rms
, single output 50.5...56.5 V DC, 10 A, opera-
tional ambient temperature –25...71°C, with cell voltage selector switch.
MELCHER
The Power Partners.
Edition 4/4.99
2/33
Rugged Environment
Sensor Type Key
AC-DC Converters >100 Watt
T Series
Type Key
Series ............................................................................... S
1
Battery nominal voltage
24 V ........................................................... 24
36 V ........................................................... 36
48 V ........................................................... 48
Cell voltage (at 20°C)
2.23 V ..................................................... 2.23
2.27 V ..................................................... 2.27
2
Temperature coefficient
–3.0 mV/K/cell ........................................... 30
–3.5 mV/K/cell ........................................... 35
–4.0 mV/K/cell ........................................... 40
–4.5 mV/K/cell ........................................... 45
other temperature coefficients on request .....
Cable length (2 m) .......................................................... 02
1
2
S 48 - 2.23 - 30 - 02
Only for LT 1240/1740/1840
For units without cell voltage selector switch
MELCHER
The Power Partners.
Edition 4/4.99
3/33
T Series
Functional Description
AC-DC Converters >100 Watt
Rugged Environment
The T unit is a primary controlled AC-DC converter with a
constant switching frequency of 65.5 kHz. The power factor
corrected single step conversion of the line input voltage to
a low output voltage results in extremely high efficiency.
The input voltage is fed via input fuse, filter and rectifier to
the main transformer. The wideband input filter with small
input capacitance generates virtually no inrush current.
Transient suppressors protect the unit against high voltage
peaks and surges. An auxiliary converter generates an in-
ternal supply voltage for the primary control logic. The input
voltage waveform is sensed by the primary control logic to
allow power factor correction.
The main transformer is connected to a rectifier, large out-
put capacitors and an efficient output filter which ensures
low output ripple and spikes and provides the necessary
hold-up time. The output voltage is fed back to the primary
control logic via a signal transformer.
The inhibit signal and the T failure signal are transferred by
a second signal transformer (no opto-couplers!).
System Good and Output voltage OK are each indicated by
a green LED, inhibit and T System Failure by a red LED.
System Good and Power Down are available as open col-
lector signals at the connector. The threshold level of the
Power Down signal can be externally adjusted at the D set
input.
Test sockets at the front panel allow the measurement of
the output voltage.
The battery charger version provides additional features to
control the output voltage. To set it to different battery float
charge voltages, a 16-step selector switch (Z) is standard.
A control input for remote output voltage adjustment, by an
external temperature sensor is available at the multifunc-
tional inhibit/U
cr
control pin. A trim-potentiometer allows fine
adjustment of the output voltage.
Fuse
Output Filter
Input Filter
Input Filter
Input Filter
P~
4
N~
6
8
10
C
y
C
y
C
y
Auxiliary
Converter
C
y
Control
Circuit
Voltage
and
System
Monitor
Isolation 4 kV
rms
Fig. 1
Block diagram
Z
P
MELCHER
The Power Partners.
Edition 4/4.99
4/33
– +
03043
C
y
12
Vo+
14
Vo+
16
Hot-plug +
NTC
18
Hot-plug –
20
Vo–
C
y
22
Vo–
24
Sys In
26
Sys Out
28
i/Ucr
30
D
32
D set
Rugged Environment
Electrical Input Data
General conditions:
–
T
A
= 20°C
AC-DC Converters >100 Watt
T Series
Table 2a: Input Data LT types
Input
Characteristic
Conditions
AC
(47...63 Hz)
min
155
85
230
LT 12xx
typ
max
255
155
min
155
85
230
2.6
4
8
3
98
4
400
B
264
75
6.3
65.536
75
6.3
65.536
4
400
B
264
75
6.3
65.536
98
4
400
B
264 V
rms
V
A
kHz
LT 17xx
typ
max
255
155
min
130
85
230
2.2
4
8
3
%
µF
ms
W
A
rms
LT 18xx
typ
max Unit
255 V
rms
130
U
i
U
i red
Input voltage range
with full output power
Input voltage range with
reduced output power
1
U
i nom
Nominal input voltage
I
i nom
I
i L
P
i 0
P
i inh
PF
Nominal input current
Input current limit
No-load input power
Input power when inhibited
Power factor
2
Input capacitance
3
Switch on delay
Input RFI level
4
Input overvoltage protection
5
Input undervoltage lock-out
Input fuse 5
×
20 mm
Switching frequency
U
i nom
,
P
o nom
1.9
3
U
i min
...U
i max
,
I
o
= 0
U
i min
...U
i max
, inhibit = low
U
i nom
,
I
o nom
U
i nom
U
i nom
,
P
o nom
I
o
=
I
o nom
EN 55014, EN 55011/022
96
6
3
C
i
t
on
u
i RFI
U
i p
U
i L
F
f
tr
Table 2b: Input Data UT types
Input
Characteristic
Conditions
AC
(47...63 Hz)
min
95
70
115
UT 12xx
typ
max
140
95
min
100
70
115
5.2
6
8
3
98
4
400
B
165
65
10
65.536
65
10
65.536
4
400
B
165
V
rms
V
A
kHz
%
µF
ms
W
A
rms
UT 17xx
typ
max
140
100
Unit
V
rms
U
i
U
i red
Input voltage range
with full output power
Input voltage range with
reduced output power
1
U
i nom
Nominal input voltage
I
i nom
I
i L
P
i 0
P
i inh
PF
Nominal input current
Input current limit
No-load input power
Input power when inhibited
Power factor
2
Input capacitance
3
Switch on delay
Input RFI level
4
Input overvoltage protection
5
Input undervoltage lock-out
Input fuse 5
×
20 mm
Switching frequency
U
i nom
,
P
o nom
U
i min
...U
i max
,
I
o
= 0
U
i min
...U
i max
, inhibit = low
U
i nom
,
I
o nom
U
i nom
U
i nom
,
P
o nom
I
o
=
I
o nom
EN 55014, EN 55011/022
98
3.8
5
6
3
C
i
t
on
u
i RFI
U
i p
U
i L
F
f
tr
1
2
3
4
5
The output power is reduced because of the input current limitation
P
o
≈
U
i
[V
rms
]
¥
I
iL
[A
rms
]
¥ h
Power factor as a function of the input voltage and load as well as harmonic distortion see
Power Factor, Harmonics.
Inrush current stays factor 10 below ETS 300132-1.
150 kHz...30 MHz: CISPR 11/22/EN 55011/22 class B, 30...300 MHz: CISPR14/EN 55014
In case of overvoltage the unit switches off temporarily, resulting in reduced output power and increased RFI.
MELCHER
The Power Partners.
Edition 4/4.99
5/33