Rockwell Automation 1772-LV,D17726.6.1 A and I MNL MINI-PLC-2/15 PROCESSO - Manual (Page 11)

Controller Components
Chapter 2
2Ć6
Terminal Strip
AC input connections are made to the terminals on the Power Supply labeled L1
and L2. L1 is the high side of the AC line and L2 is the low side (Figure 2.2).
Power Supply Indicators
The two indicators on the front of the System Power Supply (Figure 2.2) are:
DC ON
BATTERY LOW
The red DC ON indicator illuminates when the System Power Supply is
operating properly; that is, the AC line voltage and DC output voltages are
within their normal ranges. If this indicator is OFF, the incoming AC voltage
may be low, the AC line fuse may have blown, or the Power Supply may have
overloaded or been shorted.
Figure 2.3
External Battery Backup
Battery Pack
(Cat. No. 1771-BB)
MiniĆPLCĆ2/15 Processor
(Cat. No. 1772ĆLV)
MiniĆPLCĆ2/15 Processor
Transport Cable
(Cat. No. 1772ĆCD)
10105-I
In some “brownout” situations, it is possible that the DC ON indicator might be
illuminated while the Processor is disabled. This is because the Power Supply
can supply the output voltage to maintain Processor logic, even through the AC
line voltage has dropped below the normal range.
The BATTERY LOW indicator flashes when the Battery Pack voltage is low,
the batteries are not installed or they have been installed with incorrect polarity.
At this level, the batteries can support Processor memory for approximately one
week, however memory content should be checked and reentered if necessary.