General Tools and Instruments CL10 - Manual (Page 10)

Locating a Cable or Line Break Using Two Transmitters
Attempts to locate a cable or line break by feeding
the transmitter’s signal into a conductor from one
end may not succeed if stray electromagnetic fields
are present. One way to solve this problem is to
attach a second transmitter to the conductor at its
opposite end.
Additional transmitters (Part No. CL10T) are available
from General. For more details or to order, enter
“CL10T” in the SEARCH box at
www.generaltools.com.
Before you begin, make sure that the circuit is dead
(unpowered) and that all transmitters and all cables
or lines not being investigated are properly grounded,
as in Fig. 8.
To proceed, connect both transmitters as shown in Fig. 8. Then follow Steps 3 and 4 of the
procedure detailed in “Locating a Cable or Line Break Behind a Wall” on p. 8.
However, following Step 4 press and hold the CODE SEL. button of the second transmitter. This
will cause the text CODE F on the left side of the LCD to begin flashing. Press the ▲ button five
times to change the code from F to C. Then press and hold the CODE SEL. button again to save
the setting.
With the first transmitter sending Code F and the second transmitter sending Code C, complete
the procedure by performing Steps 5 through 9. The same CL10 receiver will display different
codes on either side of the cable or line break. When the receiver displays no code, it is
positioned directly at the break, where the codes overlap.
The use of two transmitters is particularly effective at pinpointing breaks in electric floor heating
systems characterized by extremely long conductors. There are only two constraints on the
technique:
1. If a shield mat is located above the heating wires, no ground connection may exist. If
necessary, separate the shield from the ground connection.
2. In addition to ensuring good grounding, make sure that there is considerable distance
between the grounding terminal of the transmitter and the target line. If this distance is too
short, it may be impossible to precisely locate the line.
10
Fig. 8. Using two transmitters to
locate a cable or line break