General Machine Products RD7000 Traceable Rod Detection - Manual (Page 30)

24 RD7000 Operation Manual
7.3.1 Connecting the clamp
Plug the clamp into the transmitter output socket.
Put the clamp around the pipe or cable and ensure that
the jaws are closed. Switch the transmitter on.
The line should be grounded (earthed) on each side of the
clamp for the signal to transfer to the line. Ground the line
if necessary. An insulated cable may be traced even if it
has no actual ground connection, providing a reasonable
length is buried either side of the clamp to provide
capacitive coupling to ground (earth).
7.2.3 Available receiver clamps
Standard clamp
The clamp plugs into the receiver accessory socket and is
used for cable identification at points where the cable can
be accessed. The standard clamp is suitable for cables
up to 100mm (4 inches) diameter.
Small clamp
The small clamp performs the same function as the
standard clamp but is useful in cramped situations where
there is insufficient access for the standard clamp.
The small clamp is suitable for cables up to 50mm
diameter.
7.3 Transmitter clamps
The transmitter clamp fits around a pipe or cable and
safely applies a signal to a live cable without interrupting
or disconnecting the supply. The clamp applies a very
discriminating signal to a target line with reduced coupling
to other lines. A clamp can sometimes be a more effective
method of applying the signal than direct connection.
The target line will carry the strongest signal. The other
lines will carry the weaker return signal. If the system
comprises only two conductors, they may carry equal
signals.
WARNING! When clamping around a power cable
ensure that the clamp is connected to the transmitter
at all times.
The clamp may buzz or vibrate if it is placed around a
power cable that has significant net current flow. This is
normal and does not harm the equipment.
Figure 7.2:
Standard clamp
Figures 7.3 – 7.4: Connecting
transmitter clamps
NOTE: It is not necessary to make a ground connection
from the transmitter when using the clamp.