GE Industrial Solutions QBDW033A0B Barracuda Series - Manual (Page 8)

GE
Data Sheet
QBDW033A0B Barracuda Series; DC-DC Converter Power Modules
36-75Vdc Input; 12.0Vdc, 33.0A, 400W Output
May 9, 2013 ©2012 General Electric Company. All rights reserved. Page 8
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 11. 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 12. 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 13. 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 10, a 100μF 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.,
UL60950-1 2
nd Ed., CSA C22.2 No. 60950-1 2 nd Ed., and
VDE0805-1 EN60950-1 2 nd Ed.
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
30 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