User`s manual

Battery life and replacement procedure Maintenance and inspection
MELSEC System Q, Hardware 10 – 21
Replacement procedure of SRAM card battery Q3MEM-4MBS and Q3MEM-8MBS
 Remove a memory card protective cover of the CPU module at power-on status of the
programmable controller (refer to section 5.1.3).
 With a flat-blade screwdriver, etc., remove the battery holder locking switch from the LOCK
position (also refer to section 5.2.3).
 Remove the battery holder from the SRAM card.
 Remove the old battery from its holder.
 Insert a new battery into the holder in the correct direction.
 Insert the battery holder into the SRAM card.
 Set the battery holder fixing switch to the LOCK position.
% Set the memory card protective cover on the CPU module.
& Monitor SM52 to verify on/off. If the special relay is still set, indicating with SD52 a low CPU
battery voltage, retry the replacement.
The following figure shows some of the steps for replacing the buffer battery,
NOTE Insert or remove the battery in the horizontal direction along the battery holder fixing guide.
Failure to do so may damage the latches of the battery holder.
Fig. 10-7: Replacing SRAM card batteries Q3MEM-4MBS and Q3MEM-8MBS
Battery holder
Battery
fixing guide
Battery holder latches
Remove memory card protective cover
Remove battery holder
Insert new battery
+ (positive)