VBT-75 S2 USER’S MANUAL REV 1
2
1.0 INTRODUCTION
1.1
General Description and Features
The VBT-75 S2 is Vanguard's second generation microprocessor-based, portable, 75kV dc
vacuum bottle tester. This lightweight, portable tester is designed for testing circuit-breaker
vacuum bottles in the field and at the shop.
Test voltages can be selected from 10 kV dc to 75 kV dc in 5 kV steps. The high-voltage test time
can be set from 5 seconds to 2 minutes. The test voltage is raised to the selected voltage and
held for the test time duration. The test voltage and leakage current are displayed on the LCD
during testing. After the test time duration has elapsed and the leakage current did not pass the
pre-set value of 100 µA, 200 µA, or 300 µA, the test voltage is returned to zero and a "Pass"
message is displayed. If a flash-over condition occurs, such as bottle failure, the test voltage is
immediately turned off, a “Failure” message is displayed on the LCD screen, and the “TEST FAIL”
LED light on the unit is also illuminated.
The presence of high voltage is indicated by an audible tone and an illuminated “HIGH
VOLTAGE” LED light. For additional operator safety, an “ARM” switch must be held down during
testing.
The VBT-75 S2 features a back-lit LCD screen (20 characters by 4 lines) that is viewable in both
bright sunlight and low-light levels. A turn-and-press knob is used to control the unit. The VBT-
75 S2's firmware can be updated in the field via the unit's built-in USB Flash drive port.
The VBT-75 S2 is furnished with a 10-foot test cable that is terminated with a quick-disconnect
test clip. A transportation case is also included.
