Precautions
1. This instrument can only be used on de-energized equipment; the grounding terminal should be reliably connected to the grounding grid,
and the instrument should be used in a spacious, safe, and reliable location as much as possible.
2. The equipment under test should be disconnected from the live high-voltage leads and switched to maintenance state, cleaned, and after preliminary insulation tests are satisfactory, the instrument can 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 situation 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. If a special situation endangering safety occurs during testing, the main power can be urgently turned off.
6. Only after disconnecting the power switch on the panel and clearly disconnecting the 220V test power supply can wiring changes be made or work be completed; 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, ensure that the low-voltage terminal (or secondary terminal) of the equipment under test has good insulation and measure in an environment with relatively low humidity.
8. When conducting experiments with large capacitance test samples, the grounding of the instrument and the grounding of the test sample should not be at the same grounding point to prevent counter-voltage or traveling waves from affecting the safety of the instrument during grounding discharge.
9. The instrument comes with a voltage boosting device; pay attention to the insulation distance of the high-voltage lead 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, do not suddenly turn off the power to avoid overvoltage damage to the equipment;
11. Although the special high-voltage wire (HVx) provided with the instrument has been tested and qualified at the factory, it should still be kept away from the human body and the low-voltage test wire (Cx) during measurement; neither the high-voltage core wire nor the high-voltage shield wire should be grounded or connected to the low-potential part of the test circuit.
The core wire and shield wire of the CX input line should 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 stable results cannot be obtained with power frequency, use offset 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 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 the paper extends from the paper outlet above the printer head, press the button to stop paper feeding. The printing 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 stabilized 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 connection current detection: Only used for positive connection measurement, 10μA～1A. Input resistance <2Ω.
Cx reverse connection current detection: Only used for reverse connection measurement, 10μA～1A. Input resistance <2Ω.
Reverse connection digital isolation communication: Uses precision MPPM digital modem to transmit the reverse connection current signal.
