Circuit Breaker Panels; Resistance/Continuity Measurement; Extension Cords; Appliance Cords - GB Instruments GDT-190A Manual Del Propietário

6.3 Circuit Breaker Panels

To test for defective circuit breakers, set the function/range
switch to the appropriate AC V setting. Touch one test lead to
the neutral (buss) terminal strip of the breaker panel and the
other test lead to the terminal on the circuit breaker
(see fig. 7). The tester should read 120V AC.
Figure 7

7. Resistance/Continuity Measurement

For resistance and circuit continuity testing with power OFF:
1) Set the function/range switch to the appropriate ohms
setting. If basic circuit continuity tests are being made,
any of the ohms settings will do.
2) Touch the test leads to the resistor or non-energized
component to be measured. Use the 2000K range when
testing for resistance values in electronic components
such as resistors and potentiometers. If the value of the
component falls within the range of another setting, reset
the function/range switch to that setting for a more
accurate reading.
Common resistance and continuity measurements
Continuity tests are probably the most frequently performed
electrical troubleshooting procedures around the home.
Always remember that continuity checks are to be made with
the power to the circuit turned OFF. Polarity of the test leads is
not a factor in making continuity checks.

7.1 Extension Cords

Unplug the cord. Set the function/range switch to any of the
ohms settings. Touch one of the test leads to one of the metal
prong ends of the cord and insert the other lead in either one
of the receptacle slots on the other end of the cord, making
sure both leads are making good contact (see fig. 8). If the
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display does not change, switch one of the test leads to the
opposite receptacle or prong, making sure of good contact.
If the display still does not change, the cord may need to
be replaced.
Figure 8

7.2 Appliance Cords

Unplug the appliance from its power source. Turn its power
switch to the ON position. Touch the test leads to the metal
prong ends of the cord. The tester should indicate a low
resistance value. If not, flex the cord while the leads are still in
contact with the metal prongs. If the display changes
erratically while the cord flexes, there may be a broken
conductor in the cord. If the display does not change at all
there may be an open circuit in the appliance. Should it be
determined that the cord is not the source of the problem, the
appliance may need to be disassembled in order to pinpoint
the problem. Refer to the owners manual of the appliance.
The manufacturer of the appliance may require that the
appliance be serviced only by a qualified repair technician.

7.3 Fuses

Note: With the power OFF, always remove a fuse from its
socket before testing it. With cartridge fuses, touch the test
leads to each end of the fuse (see fig. 9). If the fuse is good,
the display should read -0- ohms. If the display doesn't
change at all, replace the fuse. On plug-type fuses, touch the
test lead on the bottom contact and the other on the threaded
metal contact (see fig. 10). On time-delay/tamper-proof fuses,
the other metal contact is at the top of the ceramic threads.
Figure 9
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Figure 10