Finding A Break In The Boundary Wire - Husqvarna Automower 305 Technical Manual

6.5 Finding a break in the boundary
wire
A break in the loop wire is normally due to inadvertent
physical damage to the wire, e.g. using a spade while
gardening. In countries with frozen soil, sharp stones
that move in the ground can also damage the wire.
Breaks can also be due to too high a tension in the
wire during installation.
Cutting the grass very short immediately after the
installation can damage the wire's insulation. Some
kinds of damage to the insulation only produce
a break several weeks or months later. To avoid
this, the maximum cutting height should always be
selected the first week after the installation and then
reduced by 1-2 steps per week until the required
cutting height has been reached.
A wire break can be found by using Husqvarna's
break detection tool or with the manual method that
is described below. Regardless of whether a break
detection tool is used or not, the procedure is the
same; step by step halving the stretch of the wire
where the break might be until there is only a very
short distance left.
A description of how the break detection tool is used
is available in a separate service bulletin. There is a
description below of how to search for breaks without
access to the break detection tool.
1. Check that the LED in the charging station
flashes blue, which indicates a break in the
boundary wire. For further information
about the charging station's LED, see
"6.4 Troubleshooting loop signal" on
page 83.
2. Check that the boundary wire connections to
the charging station are properly connected
and not damaged.
6. TROUBLESHOOTING
3012-998
3. Disconnect all connections from the
charging station and then measure the
resistance in the boundary wire. A value
over 20 ohm indicates that there is a break.
If the measured value is less than 20 ohm
and the LED still flashes blues, the fault
is in the charging station's cabling or the
circuit board. See "5.5 Replacing the circuit
board, charging station" on page 57.
A2 A1
4. Connect the power to the charging station.
Change the connections between guide
wire and boundary wire in the charging
station.
a) Change connection A1 and Guide.
Check whether the LED is flashing yellow.
b) Put A1 and Guide back in their original
positions. Then change A2 and Guide.
Check whether the LED is flashing yellow.
If the LED is flashing yellow (i.e. the
boundary loop is intact but the guide wire is
not connected) in test a) then the break is
somewhere in the boundary wire between
A1 and the position where the guide wire is
connected to the boundary wire (thick black
line in the illustration below).
3020-059
3020-060
English - 85