14
OPERATION PROCEDURE
TOS8870A
7)
Test procedure
1.
To start test, press the START switch.
2.
When the period set by the timer has elapsed, the test voltage is cutoff and PASS judge-
ment is made and the PASS signal is generated in the forms of lamp and buzzer and make-
contact signal for about 50 ms.
3.
When a leakage current larger than the high limit reference value set by the CUTOFF
CURRENT switches has
fl
owed, the FAIL judgement is made and the output is instanta-
neously cutoff and the FAIL alarm with the lamp, buzzer and make-contact are generated.
To reset from the FAIL state, press the STOP switch.
4.
To abort the test being executed (to cutoff the output) for any reason, press the STOP
switch.
8)
Single test without using the timer
The timer built into the tester can be set to a maximum of 999 seconds. When a test time
longer than this is needed, or do not need to set the test time, perform the test without using
the timer. However, note that, when the CUTOFF CURRENT switches are set for 100 mA or
more, the continuous operation time rating of the Tester is up to 30 minutes. When the current
setting is 25.5 mA or less, the Tester may be operated for a longer period.
1.
Set the TIMER ON/OFF switch to the OFF state.
2.
Connect the DUT to the output terminals of the Tester as described in "6) Connecting the
DUT".
3.
Check that the TEST VOLTAGE dial is set at the fully counterclockwise position.
4.
Press the START switch. The DANGER lamp will illuminate to indicate that the test volt-
age is ready to be applied to the DUT.
5.
Gradually turn clockwise the TEST VOLTAGE dial until the necessary test voltage is
obtained.
6.
When the required test time has elapsed or when a condition calling for aborting the test
has occurred, press the STOP switch to cutoff the output voltage. In this case the PASS
signal is not generated.
7.
If a current exceeding the current set by the CUTOFF CURRENT switches
fl
ows in the
DUT during test, the tester issues a FAIL judgment to turn off the power immediately and
then generates a FAIL alarm. This alarm consists of an indicator, buzzer, and make-contact
signals. To cancel this alarm, press the STOP switch.
9)
Reapplication of test voltage (retest)
If the Tester is in the RESET state, the test voltage as set by the TEST VOLTAGE dial can be
delivered again to the output terminal simply by pressing the START switch.
If the Tester is generating a FAIL alarm or is in the PROTECTION state, press the STOP
switch to reset the Tester. If a PASS judgement is made at the end of the test, the auto reset
circuit operates and the Tester is automatically reset.
10) Setting the PASS-FAIL judgement reference values for withstand-
ing voltage test
The PASS-FAIL judgement by the Tester is done in a window comparator system such that
the PASS judgement is made only when the measured leakage current is between the high and
low limit reference values. The FAIL judgement can be made not only when the measured
value is larger than the high limit reference value but also when it is smaller than the low limit
reference value (0 to one-half of the high limit reference value).
