Data sheet, Test configurations, Design considerations – GE Industrial Solutions EBVW025A0B Barracuda Series User Manual

Page 7: Safety considerations

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GE

Data Sheet

EBVW025A0B Barracuda™ Series; DC-DC Converter Power Modules

36-75Vdc Input; 12.0Vdc, 25.0A, 300W Output

April 15, 2013

©2012 General Electric Company. All rights reserved.

Page 7

Test Configurations

Note: Measure input reflected-ripple current with a simulated
source inductance (LTEST) of 12 µH. Capacitor CS offsets
possible battery impedance. Measure current as shown above.

Figure 12. Input Reflected Ripple Current Test Setup.

Note: Use a 1.0 µF ceramic capacitor and a 10 µF aluminum or
tantalum capacitor. Scope measurement should be made
using a BNC socket. Position the load between
51 mm and 76 mm (2 in. and 3 in.) from the module.


Figure 13. Output Ripple and Noise Test Setup.

Note: All measurements are taken at the module terminals. When
socketing, place Kelvin connections at module terminals to avoid
measurement errors due to socket contact resistance.

Figure 14. Output Voltage and Efficiency Test Setup.

Design Considerations

Input Source Impedance

The power module should be connected to a low

ac-impedance source. A highly inductive source impedance
can affect the stability of the power module. For the test
configuration in Figure 12, a 220μF electrolytic capacitor, C

in

,

(ESR<0.7 at 100kHz), mounted close to the power module
helps ensure the stability of the unit. If the module is subjected
to rapid on/off cycles, a 330μF input capacitor is required.
Consult the factory for further application guidelines.

Safety Considerations

For safety-agency approval of the system in which the power
module is used, the power module must be installed in

compliance with the spacing and separation requirements of
the end-use safety agency standard, i.e., CAN/CSA† C22.2 No.
60950-1-07, 2nd Edition + A1:2011 (MOD), ANSI/UL*60950-1-

2011, IEC 60950-1 (2nd edition); am1, and VDE‡ (EN60950-1,
2nd.
If the input source is non-SELV (ELV or a hazardous voltage

greater than 60 Vdc and less than or equal to 75Vdc), for the
module’s output to be considered as meeting the requirements
for safety extra-low voltage (SELV), all of the following must be
true:

The input source is to be provided with reinforced

insulation from any other hazardous voltages, including
the ac mains.

One V

IN

pin and one V

OUT

pin are to be grounded, or both

the input and output pins are to be kept floating.

The input pins of the module are not operator accessible.

Another SELV reliability test is conducted on the whole

system (combination of supply source and subject
module), as required by the safety agencies, to verify that
under a single fault, hazardous voltages do not appear at

the module’s output.

Note: Do not ground either of the input pins of the module

without grounding one of the output pins. This may

allow a non-SELV voltage to appear between the
output pins and ground.

The power module has safety extra-low voltage (SELV) outputs
when all inputs are SELV.
The input to these units is to be provided with a maximum 15 A
fast-acting (or time-delay) fuse in the unearthed lead.
The power module has internally generated voltages
exceeding safety extra-low voltage. Consideration should be
taken to restrict operator accessibility.


LOAD

CONTACT AND

SUPPLY

I

I

CONTACT

V

I

(+)

V

I

(–)

V

O1

DISTRIBUTION LOSSES

RESISTANCE

I

O

V

O2

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