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Toshiba offers a compact vacuum checker (Type CI35-1D, see Figure 32) which enables a quick and
easy check on vacuum interrupter internal pressure. Alternatively, any commercially available AC high
potential tester may be used which is capable of delivering at least 25 milliamperes at 22 kV for a period
of one minute.
Figure 32 Toshiba Portable Vacuum Checker
PRECAUTIONS:
Applying abnormally high voltage across a pair of contacts in vacuum may produce X-rays. The radiation
may increase with the increase in voltage and/or decrease in contact spacing. X-radiation produced
during this test with recommended voltage and normal contact spacing is extremely low and well below
the maximum permitted by standards. As an additional safety measure, it is recommended that all
personnel keep at least 1 meter (3.3 ft) away from the vacuum circuit breaker while this test is
performed.
Radiation exposure hazard. X-rays may cause illness or injury.
Stay at least 1 meter (3.3 ft) away from the circuit breaker
during the vacuum check test .
Hazardous voltages are present during dielectric testing which
can result in severe injury or death. Only qualified personnel
should conduct this testing.
See Figure 33 for sample withstand voltage test circuit.
Figure 33 Sample Withstand Voltage Test Circuit
WARNING
WARNING