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Page 20
Interface Connections (Cont.)
Gate IN/Gate OUT (J10-13, 25)
The 3 Phase MegaPAC - EL can be paralleled with other 3 Phase MegaPAC - ELs and the
4kW MegaPAC - EL can be paralleled with other 4kW MegaPAC - ELs to increase output
power. Paralleling the chassis is similar to paralleling VI-200 (QPAC-L) or Maxi
(QPAC-XQ) DC to DC converters. The Gate Out (or PC) pin of the ConverterPAC in slot
#10 is available on J10-25, and can be used to provide input to the Gate In (or PC) pin
of the ConverterPAC in slot #1 of a different 3 Phase MegaPAC - EL and 4kW MegaPAC -
EL. The ConverterPAC in slot #1 of the second chassis must be a booster, and additional
boosters can be connected in parallel to it. The ConverterPAC in slot #10 of the first 3
Phase MegaPAC - EL or the 4kW MegaPAC - EL must be either a driver or a booster in
a parallel array. ConverterPACs paralleled from chassis to chassis must be of the same
type, voltage, and power.
The 3 Phase MegaPAC - EL and 4kW MegaPAC - EL are configured at the factory to allow
box-to-box paralleling using the ConverterPACs originally shipped in the chassis. Since
the MegaPAC is a field configurable supply, the proper configuration must be verified
before paralleling from chassis to chassis. The last two digits of the 4kW MegaPAC - EL
part number will identify whether slot #1 and slot #10 were configured for use with
VI-200 (QPAC-L) or Maxi (QPAC-XQ) DC to DC converters.
Using the example of MX7-410108-32, the last two digits, "-32," identify the type of
module in slot #1 and slot #10, respectively. A "3" indicates the chassis is configured to
parallel box-to-box using a Maxi converter. A "2" indicates the chassis is configured to
parallel box-to-box using a VI-200 converter. The above example shows the chassis is
configured for a Maxi converter in slot #1 and a VI-200 converter in slot #10.
When connecting multiple chassis in parallel, the signal ground on J10 of each chassis
should be tied together. Chassis outputs should be tied together near the power supply
and then cabled to the load. Using separate cables to provide power to the load will limit
the supplies' ability to current share properly.
Auxiliary Vcc +5V/0.3A (J10-16, 17)
The Vcc on J10-16, 17 is an auxiliary 5 V regulated power source (see Figure 8 and
Connector Pin Identification of page 17). It is +5Vdc +/–5% with respect to Signal
Ground and can supply 300 mA maximum. It is short-circuit-proof, but if shorted all
outputs will shut down through the Enable/Disable circuitry. The Auxiliary Vcc typically
powers user circuitry or is used with the Power Good circuitry to provide a pull-up
reference for the outputs of the DC Power Good circuit on a ConverterPAC. If used for
this purpose, a J10 Signal Ground must also be connected to the P2-1 Signal Ground pin
of the ConverterPAC.
Figure 8.
Auxiliary Vcc
78M05
Auxiliary Vcc
16, 17
0.1 µF
Signal Ground
J10
1, 2, 12, 15
+5V/300 mA
