HA243820
Issue 5 Mar 98
Section 3
Page 3 - 13
MODEL 346 INSTALLATION AND OPERATION MANUAL
3.2.6 BATTERY REPLACEMENT
To ensure the protection of accumulated data (Totaliser Values, Trace History, Averages, Maximums, etc.), the
RAM Battery should be changed at yearly intervals. For recorders with annotation, if the battery voltage falls
below a ‘safe’ level, or if the battery is missing, a ‘battery low’ message is printed on the chart after each power-
up.
The Clock and Supplementary Memory Protection Battery is mounted on a small circuit board which is plugged
onto the top of the annotator board (see figure 2.4.5). When changing this battery this board is removed and
discarded (note 2 below), and a replacement board fitted as follows:-
Remove the recorder from its case. Rotate the 1/4 turn fastener and lift the cover between the pen tray and the
servo drive board. Using a gentle rocking motion, carefully unplug the battery board from the top of the anno-
tator board, ensuring that the annotator board remains in place.
Fit the new battery board and close the cover, latching it shut using the 1/4 turn fastener. Return the recorder
to its case.
Notes...
1. During battery changing, data is retained (on the main board) by means of a capacitor fitted on the annotator
board. If the annotator board is removed, or if the battery replacement is not carried out promptly, accu-
mulated data will be lost.
2. Exhausted batteries must be disposed of according to the local environmental regulations covering the type
of battery involved. They should not just be 'thrown away'.
Figure 3.2.6 Battery replacement
Use PLASTIC tool