Substation O&M personnel often encounter this problem: a vacuum circuit breaker shows no external abnormalities during routine inspections and its open/close indicators are normal, yet after several years in service the vacuum degree of the arc-extinguishing chamber may still decline. Traditional judgment methods rely on the power-frequency withstand voltage test, which requires disassembling the circuit breaker or disconnecting it, takes a long time, and is not sensitive enough to slight air leakage. The DRV-8800 Switch Vacuum Degree Tester adopts the magnetron discharge principle to complete vacuum degree measurement without dismantling the arc-extinguishing chamber, providing on-site O&M personnel with a quantifiable means of comparison.
The power-frequency withstand voltage method judges whether the arc-extinguishing chamber breaks down by applying high voltage; it can only give a qualitative conclusion of "pass" or "fail", and its ability to distinguish arc-extinguishing chambers whose vacuum degree is in a critical state is limited.
The DRV-8800 Switch Vacuum Degree Tester controls the discharge process through a magnetic field, measures the gas ionization current inside the arc-extinguishing chamber, and converts it into a vacuum degree value. Its measurement range is 9.999×10⁻⁵ Pa to 1×10⁻¹ Pa, covering the common operating range of vacuum circuit breakers.
By comparison, this method does not rely on disassembly and dismantling, nor does it require high-voltage breakdown of the arc-extinguishing chamber, making it suitable for general testing while the circuit breaker is installed.
Compared with portable withstand voltage testers, the DRV-8800 records measurement results in numerical form, making it easy to build historical data archives for equipment and track vacuum degree trends.
The instrument panel uses a Chinese menu, and the test process proceeds step by step according to prompts; after wiring is completed, discharge and acquisition can be completed automatically. Test data can be stored and exported, making it convenient for O&M personnel to archive and compare. The unit has a portable structure and is suitable for on-site use in switchgear cabinets.
The instrument is suitable for vacuum degree testing of vacuum circuit breakers at voltage levels from 10kV to 35kV, and can be used for routine tests and condition assessment in substations, power distribution rooms of industrial and mining enterprises, and maintenance workshops. For arc-extinguishing chambers with abnormal vacuum degree, the instrument provides numerical indications for O&M personnel to make comprehensive judgments in combination with other testing methods.
