Vicor 4kW MegaPAC AC-DC Switchers - Manual (Page 17)

UG:107 vicorpower.com Applications Engineering: 800 927.9474 Page 17
Interface Connections
Chassis Input Power Terminals (J1)
Input AC power is applied to a plug-in connector, J1, that accepts soldered terminals
with a wire size of 12 AWG. For operation on high voltage DC input, input power can be
connected to any two input lines. A fault-clearing device should be installed at the input
of the unit. A user-accessible input fuse is not present within the unit. For an output
of 2,000-4,000W with operation on 208 Vac, 3Æ input, a 20A fuse in each input line is
acceptable. Input power cables should be shielded to minimize radiated noise effects.
Output Power Connections (+P, -P for Single Output, or J1A/J1B for Dual Outputs)
For single output ConverterPACs, these terminals are two 1/4-20 plated steel studs. The
upper stud is positive with respect to the lower stud. For dual output ConverterPACs,
there is a 6-pin Molex connector for each output. J1A pins 1 and 4 are the +Output,
and J1A pins 2 and 5 are the -Output. Pins 3 and 6 are duplicates of the Remote Sense
terminals present on J1B. Use appropriate wire size rated to handle the full output
current, including short circuit levels. Avoid large current loops in output cables; run
power and return cables next to one another to minimize inductive effects. All outputs
are isolated and can provide positive or negative outputs.
Output +/-Sense Connections (J2 for Single Output, or J1A/J1B for Dual Outputs)
Newer power supplies may have some outputs configured with the Autosense feature
that automatically locally senses the output if remote sense is not used. To check if an
output has the Autosense feature, measure the impedance from the + Out to + Sense and
- Out to - Sense pins. If the impedance is 5 ohms, then the output has
Autosense and does not require local sense jumpers.
For units without Autosense, sense connections must be made. When making sense
connections, keep in mind that although all outputs are open-Sense protected, the
+/-Sense terminals MUST be connected to their respective outputs before the 3 Phase
MegaPAC or 4kW MegaPAC is powered up. Regardless of the output polarity configured,
the +Sense should always connect to the +Power output. The -Sense connects to the
-Power output. Sense connections are not required on booster ConverterPACs, BatPACs,
or if the Local Sense option is specified.
J1-4 Earth Ground
J1-1 Line 3
J1-2 Line 2
J1-3 Line 1
J1
Figure 3.
Input Panel Connector