Understanding the Boundary Wire - Grouw M900 APP Control

The boundary wire (edge wire) defines the mowing area of the lawn mower and ensures efficient operation by preventing it from leaving the designated area.
It creates an electromagnetic signal that is detected by the mower's sensors.

Key Components:

• Boundary Wire: Installed along the perimeter of the working area.
• Signal Generator: Located in the charging station: emits the boundary signal.

Installation Checklist:

1. Plan the layout:
   • Identify obstacles such as trees, flower beds, and paths.
   • Avoid sharp angles: do not use 90° angles at corners but 2 * 45°.
   • Mark off areas such as garden ponds or steep slopes.
2. Install the wire:
   • Lay the wire flat on the ground, bury it, or place it under tiles if necessary (up to 5 cm deep).
   • Ensure a complete loop to the charging station.
   • Use pegs to secure the wire at regular intervals (every 30-50 cm).
   • Ensure there are no loose sections to avoid the mower getting stuck.
   • Be careful not to damage the wire when hammering in the pegs. Excessive hammering can cut the wire and cause faults.
3. Connect to the station:
   • Connect the ends of the boundary wire to the designated ports on the charging station (The wire that comes in under the charging station should be connected to the red terminal marked with a “+”. The wire that does NOT go under the charging station should be connected to the black terminal marked with “S1”.)
   • Test for a stable signal before starting the mower – the charging station's control light should be green.

Common Errors and Troubleshooting

Error Codes and Messages:
Robot lawn mowers often display specific error codes related to issues with the boundary wire or the robot's work being obstructed.

Note that the control light on the charging station should be constantly green. If it is flashing green, it is a sign of poor connections or a break in the wire.

1. “No signal detected” - flashes red in a triangle on the machine's display.
   • Cause: Break in the wire or faulty connection.
   • Solution:
     1. Inspect the wire for visible damage.
     2. Use a cable tester to locate the break.
     3. Repair using waterproof connectors.
2. “Weak signal”, the machine makes periodic errors, runs in circles at times, and stops in the middle of the path due to lack of signal from the edge wire.
   • Cause: Long cable runs, interference, or moisture.
   • Solution:
     1. Start by checking the machine's error messages in the app or on the machine's error memory. If it is boundary wire related, proceed with the points below.
     2. Check that the total cable length does not exceed the manufacturer's limits.
     3. Investigate if nearby devices are causing electromagnetic interference.
     4. Check for moisture in connectors or cables that may have caused oxidation and signal issues. Replace defective connectors and repair damaged cable areas.
     5. Tighten connections at the charging station.
     6. Avoid excess boundary wire coiled up behind the charging station.
     7. Ensure that the boundary wire is not too tightly packed together and disrupting the signal (see the manual for the recommended distance for your model).
3. “Mower runs outside the area”
   • Cause: Incorrect wire placement or signal interference.
   • Solution:
     1. Adjust the boundary wire to ensure proper coverage.
     2. Test the loop's continuity using the station's indicator – check if the charging station lights up green.
     3. Check if similar products are installed in the area, e.g., at a neighbour's. Adjust the distance between boundary wires and charging stations according to the manual for your model.
4. “Intermittent connection”
   • Cause: Loose connection links or physical damage.
   • Solution:
     1. Secure the wire's connections again.
     2. Replace worn or corroded connection links/connectors.
     3. Check the output terminal and the ends of the boundary wire for corrosion/rust.

Alternative Solutions:

• Boundary Wire Tester: Detects breaks or weak points in the wire.
• Check the charging station for insects:

Insects can find their way into the charging station, which can cause damage or disruptions in its function. The inspection should include the following:

-Inside the charging station: Check for cobwebs, dead insects, or live pests that may affect the electrical components.

-Ventilation openings: Ensure that the ventilation openings are free from blockages such as insects or dirt.

-Charging points: Inspect the charging contacts for insect residue that may hinder proper charging.

-General area around the charging station: Inspect the area around the station for insect nests or signs of activity that may lead to recurring issues.

• Test Area: An effective method for diagnosing faults in the boundary wire is to build a test area (approximately 2 m x 1.5 m) in a small size and try the robot within this area.
  If the machine works fine in the test area, the fault is likely in the boundary wire in the garden (see video: https://www.youtube.com/watch?v=BTnutx7QYEM).