Installation Manual
Introduction
DDR series is a DIN Rail type DC-DC converter with main features including DIN rail-type easy installation, ultra
slim width, 2:1 wide input voltage, fanless design, -40~+70
℃
wide operating temperature, 4kVdc I/O isolation,
150% peak load, current sharing, DC OK, adjustable output voltage and full protective functions.
This series of models has various input options: 9~18V / 16.8~33.6V / 33.6~67.2V / 67.2~154V and various output
options: 12V / 24V / 48V and can be used for industrial & railway control, security control, communication system
and other fields. Suitable applications include DC buck/boost regulator, increasing system insulation level and
voltage drop compensation along cable...etc.
Installation
（
1
）
Always allow good ventilation clearances, 5mm left and right, 40mm above and 20mm below, around the unit
in use to prevent it from overheating. Also a 10-15 cm clearance must be kept when the adjacent device is a
heat source.
（
2
）
The appropriate mounting orientation for the unit is vertical, the input terminals at the bottom and output on
the top. Mounting orientations other than that, such as upside down, horizontal, or table-top mounting, is not
allowed.
（
3
）
Use copper wire only, and recommended wires are shown as below.
AWG
18 16 14 12 10
Rated Current of
Equipment (Amp)
7A 10A 15A 20A 30A
Cross-section of
Lead(mm
2
)
0.8 1.3 2.1 3.3 5.3
Note: 1. Current each wire carries should be de-rated to 80% of the current suggested
above when using 5 or more wires connected to the unit.
2. The maximum allowable wire cross-sectional area for the terminal of the
SDR-75 is 12AWG/2.5 mm
2
.
Make sure that all strands of each stranded wire enter the terminal connection and the screw terminals are
securely fixed to prevent poor contact. If the power supply possesses multi-output terminals, please make
sure each contact is connected to wires to prevent too much current stress on a single contact.
（
4
）
Use wires that can withstand temperatures of at least 80°C, such as UL1007.
（
5
）
Recommended wire strapping length is 5mm (0.197”).
（
6
）
Recommended screwdriver is 4mm, slotted type.
（
7
）
The recommended torque setting for terminals is shown as below.
Model I/P
O/P
DDR-120
6.9 kgf-cm (6 Lb-in)
6.9 kgf-cm (6 Lb-in)
DDR-240
8.06 kgf-cm (7 Lb-in)
5.13 kgf-cm (4.45 Lb-in)