Specifications
12
1-800-927-9474
20-3
PFC MegaPAC Interface Connections
Chassis Input Power Terminals (J9)
Input AC power is applied to terminal block J9, using a pressure screw terminal that accepts a
maximum wire size of 12 AWG. The maximum torque recommended is 10 in-lbs. J9-1 (GND)
is Earth Ground for safety; J9-2 (L2) is the Hot connection; J9-3 (L1/N) is the other Hot or input
Neutral connection.
Chassis Output Power Terminals
Depending on the ConverterPAC used, there are two types of output power terminals available
in the PFC MegaPAC. For single output assemblies (ModuPAC/RamPAC/BatPAC), these
terminals are two 1/4-20 plated steel bolts. The positive polarity of the output is the upper bolt.
For DualPACs there is a 6-pin Molex connector for each output (J1A, J1B). For both connectors
pins 1 and 4 are the +Output, and pins 2 and 5 are the –Output. Pins 3 and 6 are duplicates of
the remote sense pins present on J2A and J2B. The top connector, J1B, provides the first voltage
listed on the DualPAC, while the bottom connector, J1A, provides the second voltage. Each
power output is isolated; thus outputs of positive or negative polarity may be configured by the
user through proper selection of an output reference terminal.
In order to minimize parasitic cable inductance and reduce EMC, the output power cables
should be routed in close proximity to one another, and large current loops should be avoided.
To avoid excessive voltage drop, do not undersize power cables, especially for high current
outputs. Excessive cable inductance coupled with large capacitive loading can introduce
instability in switching power supplies. This problem can be avoided with proper system design.
Consult Vicor’s Applications Engineering Department for assistance with applications that use
long cable lengths and excessive load capacitance.
Figure 1.
Input Connector J9
PFC MegaPAC
J9 Input Power Connection
3
2
1
Input: 85-264Vac
Earth Ground
L1
L2
F1
3
2
1
J9
Fuse
L1
L2
Ground
AC-DC
+
-
DC-DC
DC-DC
+Sense
+Out
-Sense
-Out
J2-2
J2-3
-P
+P
Positive
Output
Logic
Ground
Negative
Output
+Sense
+Out
-Sense
-Out
+
-
J2-2
J2-3
-P
+P
+
-
Figure 2.
Output Power
Connections
MegaPAC™ Family AC-DC, DC-DC Switchers