System Description

UTM-00355 | Rev 2

Page 255 of 261

 If more than one Base Ranger is in use, ensure that they are further than 10 metres apart to eliminate RF

communication interference.

Basic causes of leakage

 Poorly made joints when joining Harness Wire.

 Re-using Harness Wire.

 Leakage occurs when a damaged Harness Wire lies in water or emulsion. The water and emulsion are

both conductive substances that can result in leakage. The same can occur if a connector is left

submerged in water or emulsion indefinitely. It is advisable to raise the connectors off the ground, or at

least away from standing water, if the ground conditions are very wet.

 Detonator down hole wire – holes not correctly de-sludged, rubbing of down hole line against hole wall, bent

cable when lowering booster into a hole

 Detonator cable damaged around the insulation exposing the steel wire

 Ingress of water or moisture into connector

 Harness wire not properly secured inside connectors

 Short circuits occur when the harness wires are exposed and touch each other.

 SHORTS are typically identified by very high leakage errors - >19mA

T IS ADVISED THAT ONCE THE SYSTEM IS TAGGED

TESTED AND FOUND TO BE READY FOR BLASTING THAT

THE CONNECTED CONTROL EQUIPMENT IS SWITCHED OFF UNTIL BLASTING TIME TO REDUCE THE LIKELIHOOD

OF LEAKAGE CAUSED BY CORROSION

These errors can be located and rectified using the Leakage Test in conjunction with a

Binary Search.