Specifications

1-800-927-9474

20-10

Three Phase MegaPAC Technical Description (cont)

Upon power-up, all outputs are first disabled to limit the inrush current, and to allow the

unregulated 300Vdc to reach correct operating levels for ConverterPAC assemblies. The

internal housekeeping supply comes up within 500 ms after input power is applied, at which

time the AC Power OK signal asserts to a TTL “1,” indicating that the input power is OK. The

low-voltage power outputs come up within 10-20 ms after the AC Power OK asserts to a TTL

“1.” Output ramp-up time from Enable or General Shutdown is 10-20 ms. Output fall time from

Disable is dependent on load, but typically a few hundred microseconds.

Three Phase MegaPAC Interface Connections

Input Power Connections (J1)

Input AC power is applied to a plug-in connector, J1, that accepts soldered terminals with a

maximum wire size of 12 AWG. For operation on high voltage DC input, input power may be

connected to any two input lines. A fault-clearing device, such as a fuse, at the power supply

input is required per safety agency conditions of acceptability. A user-accessible input fuse is

not present within the unit. For an output of 2000W with operation on 208Vac, 3Ø input, a 20A

slow-blow fuse in each input line is acceptable. Input power cables should be shielded to

minimize radiated noise effects.

The Three Phase MegaPAC can also operate from a single phase 230Vac input; however, the

output power must be limited to 1200W.

Signal Ground (J10)

Signal Ground on J10 pins 1, 2, 12, and 15 is an isolated secondary ground reference for all J10

interface signals. This is not the same as Earth Ground on input power connector J1.

Enable/Disable and General Shutdown (GSD) (J10)

The Enable/Disable control lines allow individual ConverterPAC outputs to be sequenced either

on or off via TTL compatible HCMOS control inputs. For DualPACs, both outputs are

sequenced together. In parallel arrays, only the driver ModuPAC needs to be sequenced. The

GSD control line on J10-5 allows simultaneous shutdown of all ConverterPAC outputs. An

internal jumper, JP2, selects polarity, either active-high or active-low. A jumper, JP1, selects a

pull-up or pull-down source for the HCMOS control inputs.

Applications Manual

Figure 13.

Enable/Disable and

General Shutdown

10K

74HC86

+5V

JP1

+5V

JP2

Enable/Disable

General Shutdown

Signal Ground 1, 2, 12, 15

1 µF

2N2222

J10