TROUBLE SHOOTING
Drive motors
Two, 12 V DC motors with reversible direction of rotation are used to drive the lawn mower forwards. The two drive motors can rotate in different directions at the same time to give the lawn mower a tight turning circle and increase manoeuvrability.
A gearbox is engaged after the drive motors to give the lawn mower increased traction. The speed is registered by a tachom- eter which is connected to the motors. The speed of the motors is then governed by the microprocessor.
The cables from the drive motors are connected to the connec- tor X9 (left) and X8 (right) on the circuitboard in the box. The voltage to the drive motors should be 12 V.
Red cable (+) and black cable
Supply cable
Sensors
A sensor (coil) is mounted on top of the front bracket between the front wheels, see the diagram below, so that the lawn mower can sense the electromagnetic field emitted by the loop cable.
Sensor
The lawn mower uses two different systems to sense the electromagnetic field:
1.The lawn mower should, with a loop length of 300 m – at a distance of max. 35 meters from the loop cable (see diagram) sense that the loop cable is generating an electromagnetic field, see diagram, (with a 500m loop length - max 25 m). If it does not sense the electromagnetic field an error signal, 3 beeps/sec. is sounded.
NOTE! The maximum cutting area to achieve a good cutting result is approx. 1200m2.
2.The lawn mower should sense the increase in the electro- magnetic field as it approaches the loop cable and because of this turns just in front of the loop cable.
The sensor is sensitive to moisture and dirt. If, for example, grass sticks between the sensor's pins this will cause signal leakage and the lawn mower will possibly signal that it cannot sense a signal from the loop cable (3 beeps/second). The unused (smaller) pin can be cut off and insulated using silicon if the problem frequently recurs.
The part of the cable harness that runs from the sensor is connected to terminals 15 and 16 on the connector X1 on the circuitboard. (Arbitrary pole reversal.)
Moisture sensor
Using the keyboard (press C0) you can activate the moisture sensor which is located under the box so that the lawn mower can determine whether the grass is too moist to give an accept- able mowing result.
A copper rivet and a zinc plate form a galvanic element that when wet generates a voltage of 0.7V, which can be measured on the cables on the inside.
The moisture sensor only measures moisture in long grass, that is, it will not react to short, moist grass.
The cables connected to the rivet are connected to connector X5 on the circuitboard.
Cable
6 – English
