and the instrument should be used in a spacious, safe, and reliable location as much as possible.
2. The equipment under test must be disconnected from the live state, with high-voltage leads removed for maintenance, and cleaned. Only after preliminary insulation tests are satisfactory can the instrument be used for testing, to prevent damage to the instrument during voltage application due to poor insulation of the equipment under test.
3. Determine the wiring method based on the installation condition of the equipment, and select the corresponding wiring method in the menu options.
4. Correctly select the test voltage level according to different equipment, and choose the required voltage in the corresponding menu options.
5. In case of special situations that endanger safety during testing, the main power can be urgently turned off.
6. Disconnect the power switch on the panel and clearly disconnect the 220V test power supply before making any wiring changes or concluding work; when repeating tests on the same equipment, press reset and measure again, or choose to repeat after the previous test is completed.
7. To ensure measurement accuracy, especially when the loss of small capacitance test samples is small, it is essential to ensure good insulation of the low-voltage terminal (or secondary terminal) of the equipment under test, and measure in an environment with relatively low humidity.
8. When testing large capacitance samples, the grounding of the instrument and the grounding of the test sample should not be at the same grounding point, to prevent the impact of counter voltage or traveling waves on the safety of the instrument during grounding discharge.
9. The instrument comes with a voltage boosting device; attention should be paid to the insulation distance of the high-voltage leads and personnel safety; 10. The instrument should be reliably grounded; poor grounding may cause machine protection or danger.
10. After the instrument is started, except for special circumstances, it is not allowed to suddenly turn off the power, to avoid overvoltage damage to the equipment;
11. The special high-voltage wire (HVx) provided with the instrument has been tested and qualified at the factory, but during measurement, it should still be kept away from the human body and the low-voltage test line (Cx); neither the high-voltage core wire nor the high-voltage shielding wire should be grounded or connected to the low-potential part of the test circuit.
The core wire and shielding wire of the CX input line must not contact the high-voltage part of the test circuit.
12. The instrument should be protected from moisture and severe vibration.
13. When on-site interference is significant and power frequency measurement cannot yield definite results, use heterodyne frequency measurement; otherwise, use power frequency measurement.
14. If after issuing a measurement command, the measurement result does not appear on the screen for a long time (1 minute), it may be due to excessive capacitance of the test sample or a system crash; restart the instrument and lower the test voltage before measuring again.
15. A short circuit in the test sample will prevent measurement, and the instrument will automatically protect itself. When a section of paper extends from the paper outlet at the top of the machine, press the button to stop paper feeding. The paper is allowed to be pulled outward.
Instrument Structure
Measurement circuit: all calculations such as Fourier transform, complex number operations, range switching, and variable frequency power supply control.
Control panel: printer, keyboard, display, and communication relay.
Variable frequency power supply: uses SPWM switching circuit to produce high-power sine wave regulated output.
Step-up transformer: boosts the variable frequency power supply output to the measurement voltage, with maximum reactive power output of 2KVA/1 minute.
Standard capacitor: internal Cn, measurement reference.
Cn current detection: used to detect the current of the internal standard capacitor, 10μA～1A. Input resistance <2Ω.
Cx positive wiring current detection: only used for positive wiring measurement, 10μA～1A. Input resistance <2Ω.
Cx reverse wiring current detection: only used for reverse wiring measurement, 10μA～1A. Input resistance <2Ω.
Reverse wiring digital isolation communication: uses precision MPPM digital modulation and demodulation to transmit the reverse wiring current signal.
