Extech Instruments CB20 User Manual page 6

Receptacle Wiring Test
1.
Plug the Transmitter / Receptacle tester into the outlet.
2.
The three LED's will indicate circuit condition. The diagram lists all of the conditions that the
CB20 can detect. The LED's in this diagram represent the view from the GFCI button side of
the transmitter. When viewing the other side of the transmitter the LED's will be a mirror
image of those shown here.
3.
The tester will not indicate the quality of the ground connection, 2 hot wires in a circuit, a
combination of defects, or reversal of ground and neutral conductors.
Receptacle GFCI Test
1. Before using the tester, press the TEST button on the installed GFCI receptacle, the GFCI
should trip. If it does not trip, do not use the circuit and call a qualified electrician. If it does
trip, press the RESET button on the receptacle.
2. Plug the Transmitter / Receptacle tester into the outlet. Verify that the wiring is correct as
described above.
3. Press and hold the test button on the tester for at least 8 seconds, the indicator lights on
the tester will shut off when the GFCI trips.
4. If the circuit does not trip, either the wiring is incorrect, or the wiring is correct and the GFCI
is defective.
CORRECT WIRING
GFCI TESTING IN PROGRESS
HOT ON NEUTRAL WITH HOT OPEN
HOT AND GROUND REVERSED
HOT AND NEUTRAL REVERSED
OPEN HOT
OPEN NEUTRAL
OPEN GROUND
OFF
ON
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