User's Manual

30 LS420 Universal User Manual V2.91 2003-01-21.doc
3.3 Changing Anti-two-block Batteries V1.5
ALWAYS replace all four batteries of a two-block sensor at the
same time.
Replacing just one, two or three batteries will cause the un-
changed batteries to reverse polarity. This means that all batteries will need to
be changed again within the next couple of days or even hours…
• Batteries should be changed when reduced to 10 – 20 % of full charge.
• The following items are necessary to successfully change the batteries of the anti-two-
block:
a) A monkey wrench.
b) Four new, high-quality, alkaline “C”-cell batteries (Duracell Ultra or Energizer E2 rec-
ommended).
Step 1)
Remove the anti-two-block from the crane and clean off dust and grime.
During the following operations the interior of the anti-two-block
must be protected from dirt and humidity at all times.
Do not unscrew the white nylon hex bolt of the antenna.
Do not unscrew the small screw to the left of the antenna.
Do not remove the small black plastic plug on the bottom of the anti-two-block.
Step 2)
Place the anti-two-block on the edge of flat surface. Using a monkey wrench, partly
unscrew (about a half-inch) the large white nylon hex bolt through which the wire rope passes.
Step 3)
Carefully remove the plunger assembly, without
separating it from the cover, and place it on a clean and dry sur-
face.
Step 4)
The four batteries will easily slide out.
Step 5)
Insert the four fresh, clean, top quality, alkaline “C”
cells according to +/- schema printed on the back of the sensor.
Step 6)
Replace the plunger
assembly. Correctly align the bot-
tom cover before screwing in the
white nylon hex bolt through which
the wire rope passes. This hex
bolt should be well tightened with
the monkey wrench.
If battery replacement has been successful the LED on the bottom of the sensor will flash red
when the wire rope is pulled and the “Low Batt” icon of the cabin-mounted display will no longer
be lit. Use the test function of the cabin-mounted display unit to confirm new battery status.
Step 7)
Reinstall the anti-two-block.