Vacuum Degree Tester

Vacuum circuit breaker is a high voltage instrument used in electric power system. Its core element is vacuum interrupter. The vacuum interrupter works based on vacuum conditions, its quality is not easy to detect as oil switch or SF6 switch. Traditionally, the users of vacuum circuit breakers determine vacuum degree of interrupters by means of the test method for dielectric strength at power frequency, which can only rough estimate an interrupter with heavy degree of vacuum.

ZKY-2000 Type vacuum degree tester is designed for estimating vacuum degree of a vacuum interrupter, based on the principle of magnet controlled discharge, taking single-chip computer as main control unit, with fully automatic testing process. Its sampling design adopts ionic charge for scaling, instead of traditional electric current peak method. In this way, interference from transient state electric source during testing is effectively suppressed, testing becoming more stable and reliable. Because of a computer as the main control unit, electric leakage current produced from environmental factors can be easily taken off from this tester. One of the most important features of this tester is to realize dismount-free testing of vacuum interrupter, directly displaying vacuum degree value, helping the user master vacuum state in interrupter in detail, providing reliable basis for regularly replacing interrupter, providing powerful guarantee for safely running electric network, overcoming the weakness of the test method at power frequency of only judging whether an interrupter is scrapped or not.

This tester is with high measuring precision and powerful anti-interference capacity, simple to operate, easy to carry, greatly applicable for site testing for power supply units. This tester is one of necessary instruments for production, installation, adjustment, testing and maintenance of vacuum circuit breakers.

Pull two contacts of the interrupter to certain separation, applying high voltage pulse, sending great current through coil around the outside of interrupter, so pulse magnetic field synchronizing with high voltage is generated in the interrupter. Under the action of pulse magnetic field, electron in the interrupter is in helical motion, impact ionization between electron and residual gas molecule is generated, resultant ionic current is approximately proportional to density of residual gas, i.e., vacuum degree. For different vacuum tubes, in the condition with the equal vacuum degree, the values of ionic current will be different. After obtaining value of ionic current, by means of ionic current-vacuum curve, calculation for vacuum degree will be automatically finished by the computer, and value of vacuum degree is displayed.

1.    Measuring range for vacuum degree: 9.999×10^-1 to 1×10^-5

2.    Measuring range for ionic current: 9.999×10^-1 to 1×10^-7

3.    Measurement error: <10%

4.    Measurement resolution: 10^-5 Pa

5.    Allowable environmental temperature: -20℃ to 50℃

6.    Air humidity: ≤80%RH

7.    Power supply: AC, 220V, 50Hz±10%

8.    Overall dimension: 420×290×210mm

9.    High voltage output: pulse 30kV, 15kHz

10. Weight: 8kg

(1)   There are two purposes with this tester:

1.    Used for quality control for interrupter in vacuum interrupter production line and warehouse-in inspection for interrupter in circuit breaker manufacturer.

2.    Used for detecting vacuum degree of vacuum interrupter mounted on the switching machine. These detecting is mainly used for estimating bearing capacity of vacuum interrupter in routine overhaul and capacity test of power supply departments.

(2) Wiring:

Connect output terminal of magnetic controlled current in the panel to magnetic coil via wire to let contacts of the interrupter at separation state (coil covers outside the interrupter), connect high voltage line and signal input line separately to dynamic and static terminal of the interrupter. Note: high voltage line shall be overhead (shown as in the figure).