33
EMITTER
Live
Neutral
Earth
Fuse box
Earth independant from the circuit
to be traced (radiator, plumbing...)
WARNING :
In conclusion to the large loop connection, connecting the
Emitter directly in an electrical socket is prohibited.
Connecting to a large loop
If the Emitter is directly connected to an electrical socket, the outward
pulsed current is carried by one of the wires (live) and the return by the
other (neutral).
In this case the conducting wires being in parallel the emitted magnetic
fields are equal but in opposite directions. They then have a tendency to
cancel each other and the Receiver only detects the difference between
the two (insignificant). This big loss of signal makes detection difficult and
it becomes impossible as soon as the user moves away from the circuit.
To avoid this weakening, the user connects up so that "one of the currents,
outward or return, is separated". This is the large loop connection which
consists of connecting :
- One of the leads to the live side of the socket
- The other lead to an earth or negative of another socket which doesn’t
follow the same route as the circuit to be traced.
NB : This large loop connection of the Emitter solves this problem in the
majority of cases. If RCDs are used in the circuit then the polarity
of the LOCAT must be connected as shown in the diagram. Failure
to do so will cause the RCD to trip.
Connecting to a large loop
