Vicor PFC MegaPAC-HPEL Power Factor Corrected AC-DC Switchers - Manual (Page 6)

UG:119 vicorpower.com Applications Engineering: 800 927.9474 Page 6
Installing ConverterPACs as Drivers
ConverterPACs can be installed in empty slots by simply sliding in the new
ConverterPAC and securing the screw at the base. Power and interface connections can
be made after the ConverterPAC has been installed.
Installing Booster ConverterPACs to Increase Output Power
ConverterPACs can be paralleled for more power. Additional power to an output is
obtained by connecting one or more boosters in parallel with a single driver. The
driver can be placed in any open slot. All boosters should be inserted in the slots to the
immediate right of the driver as viewed from the output end of the MegaPAC. Figure
2 shows a driver placed in slots #1 and 3, boosters placed in slots # 2 through 4. After
inserting the driver and boosters, they are paralleled using bus bars across the positive
and negative output studs. Drivers should not be paralleled with each other. Bus bars
between a driver and booster(s) should never be disconnected. For help in identifying
boosters and drivers, refer to the Part Numbering section on Page 8. Please note that
total output voltage should not exceed the converter baseplate-output isolation rating of
400 V. For detailed guidelines on how outputs should be placed in series, please refer to
the Applications Note (Creating High Voltage Outputs) available on the website
at
www.vicorpower.com .
ConverterPAC Functional Description
ConverterPACs are the family of slide-in output assemblies used in MegaPAC power
supplies. Most ConverterPACs of the same length are interchangeable within a MegaPAC
or between different AC input MegaPAC chassis. They can be added, moved, or changed
as necessary. A key feature of the Extended Length ConverterPAC is the low ripple
and noise output to 10 mV p-p or 0.15%, whichever is greater. The following
Extended Length ConverterPACs can be used in the PFC MegaPAC/EL - Low Noise.
QPAC (L)
The QPAC output assembly consists of a VI-200 DC-DC converter that converts the
unregulated high voltage bus to the desired regulated output voltage. Each QPAC (L) can
provide up to 200 Watts of output power, and booster QPACs can be added in parallel
for more power. Power and slave QPACs can be added in parallel for more power. QPACs
are fused with a PC-Tron, DC-rated, fast-acting fuse. An active preload ensures the
DC-DC converter operates in its highest noise performance range. As the load on the
Figure 2.
Paralleling ConverterPACs
Driver
Bus Bars for Paralleling
Loosen screw to
remove ConverterPAC
Boosters
1 2 3 4 5 6 7 8
+
_ VI-200
QPAC