Vicor Mini MegaPAC AC-DC Switcher - Manual (Page 14)

UG:110 vicorpower.com Applications Engineering: 800 927.9474 Page 14
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 10 AWG. The maximum torque recommended is
10 lb-in. 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. Mini MegaPACs are normally
shipped for operation from a 230 Vac source. To operate from a 115 Vac source, a
strapping wire should be connected from S1(J9-5) to S2 (J9-4). Strapping wires are
included with every shipment. When operating from a 300 Vdc source, remove strap.
A fault clearing device, such as a fuse or circuit breaker at the power supply input, is
required per safety agency conditions of acceptability. It should be sized to handle the
start-up inrush current.
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 J2A and J2B. 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 have 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.
If units do not have 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 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 and BatPACs. Sense pins
can be accessed on J1A/J1B on dual output units.
Figure 3.
Input Panel Connectors
115V OPERATION
JUMPER FOR
J9-5 120 VAC
J9-4 120 VAC
J9-3 AC NEUTRAL
J9-2 AC HOT
J9-1 EARTH GROUND
J9 INPUT CONNECTIONS L2 S2 L1/N
HERE.
EARTH
JUMPER
230 VAC
AS IS
-OR-
115 VAC
WITH S1-S2
DO NOT
RUN W/O
GROUND
S1