TOS8870A INTRODUCTION 1
INTRODUCTION
General
Model TOS8870A is a combination of an withstanding voltage tester and an insulation resistance
tester, and it is capable of performing withstanding voltage test and insulation resistance test in one
continuous process.
As for the withstanding voltage tester, the Tester can provide a maximum output voltage of 5 kV
and an output capacity of 500 VA, and can be used for withstanding voltage test in compliance with
JIS, UL, CSA, BS and other major electrical standards and ordinances. As for the insulation resis-
tance tester, the Tester has two ranges of 500 V/ 1 000 M
Ω
and 1 000 V/ 2 000 M
Ω
.
The Tester can perform a PASS-FAIL judgement function when in either the withstanding voltage
or insulation resistance test mode. A PASS-FAIL judgement is with a window comparator type.
When in withstanding voltage test, the Tester is capable of generating a FAIL judgement not only
when the detected leakage current is greater than the high limit reference value preset on the front
panel of the Tester but also when it is less than the low limit reference value (which is continuously
adjustable down to one-half of the high limit reference value), thereby contributing to make PASS-
FAIL judgement including test of open circuiting of leadwires and imperfect contacting of connec-
tions.
The Tester is incorporated with a function to deliver signals representing the result of PASS-FAIL-
judgement and the state of the Tester, and a remote control function. The signals namely are TEST
ON, PASS, READY, and FAIL alarm (contact signals). The Tester is incorporated also with a
remote control function for test set/reset. These features can be utilized for automatic test with
labor economization.
Its sequence circuit is designed with full attention to noise to prevent erroneous operation which
could be caused by noise.
• Although many safety features are incorporated in the Tester, a deadly accident may
occur when the operator touches the device under test (DUT) or the probe.Safety
guards around DUT should be considered for safe operation.Also, other precaution,
which deemed necessary for the tester and the devices, shall be maintained under
positive control.
WARNING
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