Power Probe ECT 2000 - Manual (Page 10)

10
3. Capacitive Coupling to Parallel Floating Circuits
Another characteristic of the open circuit signal is that it will capacitive couple to parallel fl oating circuits. (See: “Bench Tracing a Wire Harness”
pg. 24)
Fig. 1
Problem circuit not isolated
Signals are all
over the place,
because the
problem circuit
has not been
isolated
4. Travels to ALL Open Ends
In Fig. 1 we are injecting an open circuit signal into a
parallel circuit that has three wires. Two of those wires lead to
open switches and the other leads to the open/break. As you can
see the open circuit signal travels to all open ends. This makes it
necessary to isolate the problem circuit away from the others.
5. Can only be present in a circuit when there is a resistance
greater than 100 ohms
(See: Open Circuit Signal vs Grounded Circuit Signal” pg. 22)
6. Has NO Polarity
The open circuit signal does not have a polarity therefore the ECT
receiver gives no direction indication as to break in the wire. You
will need to logically reason the direction of the break in the circuit
and then continue to trace it.
7. 8 volt amplitude and 4 kilo-Hertz signal
The 4 Kilo-Hertz signal of the open circuit signal can be detected by the SMART receiver. (See: “Locking the Sensitivity for Open Circuits” pg. 14)
You can also use the Power Probe III for open circuit signal detection by direct contact. (See: “Verify an Open Circuit” pg. 23)