DS_V48SC3R325_06262013

E-mail: DCDC@delta.com.tw

http://www.delta.com.tw/dcdc

P8

Basic insulation based on 75 Vdc input is provided

between the input and output of the module for the

purpose of applying insulation requirements when the

input to this DC-to-DC converter is identified as TNV-2 or

SELV.

An additional evaluation is needed if the source is

other than TNV-2 or SELV.

When the input source is SELV circuit, the power module

meets SELV (safety extra-low voltage) requirements. If

the input source is a hazardous voltage which is greater

than 60 Vdc and less than or equal to 75 Vdc, for the

module’s output to meet SELV requirements, all of the

following must be met:



The input source must be insulated from the ac

mains by reinforced or double insulation.



The input terminals of the module are not operator

accessible.



A SELV reliability test is conducted on the system

where the module is used, in combination with the

module, to ensure that under a single fault,

hazardous voltage does not appear at the module’s

output.

When installed into a Class II equipment (without

grounding), spacing consideration should be given to

the end-use installation, as the spacing between the

module and mounting surface have not been evaluated.

The power module has extra-low voltage (ELV) outputs

when all inputs are ELV.

This power module is not internally fused. To achieve

optimum safety and system protection, an input line fuse

is highly recommended. The safety agencies require a

normal-blow fuse with 20A maximum rating to be

installed in the ungrounded lead. A lower rated fuse can

be used based on the maximum inrush transient energy

and maximum input current.

Soldering and Cleaning Considerations

Post solder cleaning is usually the final board assembly

process before the board or system undergoes electrical

testing. Inadequate cleaning and/or drying may lower the

reliability of a power module and severely affect the

finished circuit board assembly test. Adequate cleaning

and/or drying is especially important for un-encapsulated

and/or open frame type power modules. For assistance

on appropriate soldering and cleaning procedures,

please contact Delta’s technical support team.

FEATURES DESCRIPTIONS

Over-Current Protection

The modules include an internal output over-current

protection circuit, which will endure current limiting for an

unlimited duration during output overload. If the output

current exceeds the OCP set point, the modules will shut

down, and will try to restart after shutdown(hiccup mode).

If the overload condition still exists, the module will shut

down again. This restart trial will continue until the

overload condition is corrected.

Over-Voltage Protection

The modules include an internal output over-voltage

protection circuit, which monitors the voltage on the output

terminals. If this voltage exceeds the over-voltage set

point, the protection circuit will constrain the max duty

cycle to limit the output voltage, if the output voltage

continuously increases the modules will shut down, and

then restart after a hiccup-time (hiccup mode).

Over-Temperature Protection

The over-temperature protection consists of circuitry that

provides

protection

from

thermal

damage.

If

the

temperature exceeds the over-temperature threshold the

module will shut down.The module will restart after the

temperature is within specification.

Remote On/Off

The remote on/off feature on the module can be either

negative or positive logic. Negative logic turns the module

on during a logic low and off during a logic high. Positive

logic turns the modules on during a logic high and off

during a logic low.

Remote on/off can be controlled by an external switch

between the on/off terminal and the Vi (-) terminal. The

switch can be an open collector or open drain. For

negative logic if the remote on/off feature is not used,

please short the on/off pin to Vi (-). For positive logic if the

remote on/off feature is not used, please leave the on/off

pin to floating.

Figure 16: Remote on/off implementation