Overcurrent Protection (All Supplies); Timing Diagram - GE 90-30 PLC Series Installation And Hardware Manual

4

Overcurrent Protection (all Supplies)

The 5V logic output is electronically limited to 3.5 amps (7 amps for high capacity supplies). An
overload (including short circuits) is sensed internally and causes the supply to shut down. The
supply will continually try to restart until the overload is removed. An internal fuse in the input
line is provided as a backup. The supply will usually shut down before the fuse blows. The fuse
also protects against internal supply faults.

Timing Diagram

The timing diagram below shows the relationship of the DC input to the DC outputs and to the
Power Supply OK signal (PSOK) generated by the power supply. When power is first applied, the
PSOK signal goes false. This line remains false for a minimum of 20 msec after the +5V bus is
within specifications, then it becomes true.
If input power is interrupted, the +5V bus will remain within specifications and PSOK will remain
true a minimum of 0 milliseconds. PSOK then goes false. The +5V bus will remain within
specifications for an additional 4 milliseconds minimum to allow an orderly shutdown of the
system.
INPUT
POWER
ON
+5V OUTPUT
(5.1V TYP.)
20MS
(MIN)
PSOK
Figure 4-12. Timing Diagram for all Series 90-30 Power Supplies
4-18 Series 90-30 PLC Installation and Hardware Manual – August 2002
VOLTAGE
OVERSHOOT
5% (MAX)
97% (MIN)
MOMENTARY
POWER
LOSS
VOLTAGE
OVERSHOOT
5% (MAX)
HOLD
UP
TIME*
20MS
(MIN)
4MS
(MIN)
*HOLD-UP TIME: 20 ms, minimum for IC693PWR321/330
14 ms, minimum for IC693PWR322
10 ms, minimum for IC693PWR331/332
INPUT
POWER
OFF
HOLD
UP
TIME
10MS
(MIN)
4MS
(MIN)
GFK-0356Q