Siemens S5-135U/155U - Manual (Page 97)

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System Manual
C79000-G8576-C199-06
Whether or not you require a lithium battery depends on what type of backup
you require for your system. The following table will help you to decide.
IF... THEN...
You require long backup times and do not want to
supply an external backup voltage, you need a lithium battery.
You require redundant backup and do not want to
supply an external backup voltage, you need a lithium battery.
Short backup times are sufficient, you do not need a lithium
battery.
You do not require redundant backup, you do not need a lithium
battery.
The lithium battery must be ordered separately (see Ordering Information).
The backup battery (type C) contains lithium (more than 0.5 g) and is
delivered separately from the power supply unit, because of special shipping
regulations.
Depending on the manufacturer, the battery’s plus pole may have a protective
cover. You must remove this cover before you place the battery in the battery
compartment.
!
Caution
Improper replacement of the battery can result in the danger of explosion.
If should only be replaced by the same type or an equivalent one
recommended by the manufacturer. Used batteries should be disposed of
according to the manufacturer’s instructions.
The backup battery must be fitted before the programmable controller is
started up. Without a backup voltage, the PLC will remain in the Stop state
after system voltage is switched on.
Only use battery compartments marked -A1155-B21 (red label).
Fit the lithium battery in the following steps:
Step Action
1 Slide the battery compartment cover (A) downwards.
2 Pull the battery compartment (B) out.
3 Insert the lithium battery in the battery compartment.
Important: Ensure correct polarity.
4 Slide the battery compartment in.
5 Close the cover.
Starting up with a
Lithium Battery
When do you
Require a Lithium
Battery?
Notes Relating to
the Lithium Battery
How to Fit the
Lithium Battery
Central Controllers and Expansion Units Power Supply Units