Vicor 4kW MegaPAC AC-DC Switchers - Manual (Page 5)

UG:107 vicorpower.com Applications Engineering: 800 927.9474 Page 5
Configuring and Reconfiguring MegaPACs
Most ConverterPACs of the same length can be easily added, replaced, or moved by
sliding the assemblies in or out of a MegaPAC chassis. They are driver ConverterPACs
and can be inserted into any available slot. For outputs greater than 200 Watts, a driver
ConverterPAC and one or more booster ConverterPACs will be used. For outputs
greater than 500 Watts (in the 4kW MegaPAC), a driver UniPAC and one or more booster
UniPACs will be used. Arrays of drivers and boosters should be configured so all
boosters are placed in the slots to the immediate right of the driver when looking at the
output end of the MegaPAC.
Prior to removing or installing ConverterPACs, you must remove power from the
MegaPAC and wait 5 minutes. Failure to do so can result in personal injury or
damage to the supply.
Take standard ESD precautions when handling ConverterPACs.
Removing ConverterPACs
ConverterPACs can be removed by loosening the captive screw at the base. Once this
screw has been loosened, the ConverterPAC will slide out of the chassis. Once a
ConverterPAC has been removed, the empty slot MUST be filled with either another
ConverterPAC of the same length or an airblock. If the slot is left empty, it will
provide an airflow escape and cause failure to the power supply.
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 to 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 10. Please note that
total output voltage should not exceed the converter baseplate-output isolation rating of
400V. For detailed guideline on how outputs should be placed in series, please refer to
the Applications note available on the website at
www.vicorpower.com .
Driver
Bus Bars for Paralleling
Loosen screw to
remove ConverterPAC
Boosters: Slots 2, 3, 4
1 2 3 4 5 6 7 8
L1 L2 L3
9 10
Figure 2.
Paralleling ConverterPACs