ALLEN BRADLEY 1747-L551 PLC Processor

9–4
Maintaining Your Control System
Installing and Replacing
the Battery of the SLC 5/01
or SLC 5/02 Processor
Back-up power for RAM is provided by a replaceable battery. The
lithium battery provides back-up for approximately five years for the
1747-L511 and two years for the 1747-L514 and 1747-L524. A red
BATTERY LOW LED alerts you when the battery voltage has fallen
below a threshold level.
Once the BATTERY LOW LED goes on, do not remove processor
power or your program may be lost. Replace the battery as soon as
possible. You can replace the battery while the processor is
powered.
For battery installation or replacement do the following:
1. Open the door of the processor.
2. If you are:
installing a battery in a new processor (battery never installed
before), remove the jumper from the battery connector socket.
Store the jumper in safe place for possible future use without the
battery.
replacing an old battery, unplug the existing battery connector
and remove from the retainer clips. The figure below shows
where to install the battery in a SLC 5/01 or SLC 5/02 processor.
3. Insert a new or replacement battery in the holder making sure it is
held in by the retainer clips.
4. Plug the battery connector into the socket. See the figure below.
White
Lead
Red
Lead
Battery
Connector
Retainer
Clips
—LASER—
Lithium
+SANYO
5. Close the processor door.
Publication 1747-6.2