Thales 421, Эксплуатация и обслуживание, Страница: 160 / 256

LLZ 421
Maintenance Operation and Maintenance
ILS 420
6−18
Ed. 01.10 SOAC
Caution should be observed when mixing high−density acid with water. The acid should
be added to the water in a thin stream whilst stirring with a clean wooden rod. If water is
added to the acid, the latter will splash dangerously.
Splashes of acid should be neutralized and salts removed using a lukewarm soda solu-
tion (100 g soda to 1 l water).
Care should be taken to ensure that no soda solution gets into the cells. After treating with
the soda solution, clean with clear water and wipe dry.
Sufficient ventilation should be provided for the battery compartment. The acid vapors are
aggressive; be careful of clothing.
Specially marked and stored test leads should be used for battery measurements on ac-
count of the acid residues which may be present.
The following points should be observed in order to prevent false acid density measurements with
the areometer:
a) The areometer float should not stick to the side or hit the top, and should always be clean.
b) When the battery is charged or discharged a period of about 30 minutes should be waited before
commencing measurements in order to allow time for the acid density between and above the
plates to become uniform.
c) If specially purified water is used for topping up, no measurements should be performed for the
next few hours.
d) If the temperature should deviate substantially from the reference temperature of +20 °C, this
should be taken into consideration when performing measurements (the density decreases with
higher temperatures and increases with lower temperatures).
6.4.1.2.5 Filling the Batteries with Acid
A particular quantity of accumulator acid is required for each battery type. This quantity is specified
by the manufacturer or is defined by the cell levels (acid level indicator or max. marking on the cell
box). The tolerance of the accumulator acid density is ± 0.01 kg/l.The acid temperature should not
35 °C, since heat is developed internally following filling, and higher acid temperatures may
cause the maximum permitted battery temperature to be exceeded.
In hot climates with the associated high ambient temperatures it is particularly difficult to cool down
the batteries during the day. We therefore recommend slowly filling the batteries half full in such re-
gions, then filling them right up the next day after they have cooled down during the night.
NOTE: The battery should not be removed from its transport packaging until immediately prior
to startup (see also Section 6.4.1.1).
6.4.1.3 Startup
Initial charging or activation.
6.4.1.3.1 General
The initial charging fully activates the plates, and for this special rules and data apply which deviate
from the standard values for battery operation and charging procedures. If the initial charging proce-
dure is not performed in accordance with the specifications, the plates will only be partly activated;
coarse sulphates will be produced, and the batteries will not reach their full capacity. Such damage
can only sometimes be eliminated by means of a time−consuming desulphating procedure. As men-
tioned above in 6.4.1.1, the batteries may be supplied non−filled in either a dry pre−charged state,
or a non pre−charged state.
This is not apparent externally except from the color of the plates. The positive plate of activated bat-
teries has a brown coloring (PbO
2
), whilst the negative plate is light grey (Pb).