C.A.T4 and Genny4: Locating MethodsFollow
LOCATING SMALL DIAMETER CABLES
C.A.T4 and Genny4 have been designed to increase the likelihood of detecting smaller cables such as telephone lines or CATV, particularly service drops from the road or pathway to a property. The Small Diameter Locate frequency transmitted from the Genny4 is designed to ‘jump’ onto these cables using one of three methods:
Signal jumping through external insulation/coatings
With the Genny4 switched off, plug the direct connection leads into the Genny4 and connect the black lead to the earth stake or suitable ground point. Clip the red lead directly onto the cable insulation to allow the Small Diameter Locate signal to jump onto the metallic wires inside. If clipping on is not possible, place the red clip as near to the cable as possible, which may include clipping to the protective cover of the service. Alternatively, run the red lead around a non-metallic casing or conduit containing the target utilities, and clip it to itself to achieve this effect.
Switch on the Genny4 and set the C.A.T4 to Genny mode to locate the buried cable. Note that the signal boost function will not have a significant effect in this mode.
Signal jumping from an accessible cable
If a small diameter cable runs close to, or parallel to, a more accessible cable – e.g. a street lighting cable, the Small Diameter Locate signal may be able to jump from one cable to another. Use the Direct Connection or Signal Clamping methods as described below to transmit both signals to the accessible cable. When scanning an area for underground utilities, the jumping Small Diameter Locate frequency can be differentiated from the standard Genny signal by a different audio tone.
Connection to a power cable sheath should only be undertaken by qualified personnel.
Direct Connection is an effective way to apply the Genny4 locate signal to a specific cable or pipe network so that it can be traced from above ground. Connections can be made to any metallic part of the pipe or cable such as valves, meters, junction boxes, street lights, pipeline markers or other access points.
With the Genny4 switched off, plug the Direct Connect lead into the accessory socket. Attach the red lead to the pipe or cable (if necessary, clean the connection point to ensure a good electrical contact). If the jaws of the clip do not open far enough, and if the connection point is a suitable material, use the supplied magnet.
Connect the black lead to the earth stake which should be secured in the ground 3 – 4m away from, and at right angles to the target line.
Alternatively the black lead may be clipped to a valve box, manhole cover or another earthed point. Use the earth spool lead to extend the earth connection if necessary.
Switch the Genny4 on. A good connection is indicated by a drop in loudspeaker tone. If there is no tone, or if the power boost LED flashes, replace the batteries.
Use the C.A.T4 to scan the area for the target pipes or cables (see 'Locating with C.A.T4 on the C.A.T4 and Genny4: Locating Methods 2 article ).