I. Reference for the use of matching current limiting resistors in DC high voltage generators
Theoretically, a current limiting resistor R (see Figure 9) should be set in both AC and DC high voltage test circuits. Its purpose is to limit the current when the test object Cx discharges or breaks down, so as not to damage the test equipment during high voltage short circuits. However, in practice, for various reasons, the current limiting resistor is not used. Therefore, when designing our products, our company considered that if the current limiting resistor is not used, the high voltage lead falling to the ground will not damage the tester. In addition, we have designed a current limiting resistor that is very easy to install. For this reason, the following suggestions are made for the use of current limiting resistors:
1. When our company's products are used for DC high voltage tests on zinc oxide arresters, ordinary valve type arresters, high voltage switches, power transformers and other power equipment, the current limiting resistor can be omitted.
2. When testing power cables, a current limiting resistor should be connected in series in the high voltage circuit (simply screw the matching current limiting resistor onto the high voltage output bolt at the top of the voltage doubling cylinder).
II. Use of the discharge rod for DC high voltage generator
1. The special discharge rod must not directly contact the high voltage DC discharge. It should maintain a certain distance. When the tip of the discharge rod initially produces corona discharge and the voltage on the test object gradually drops to 20% of the test voltage, then touch the discharge rod to the microammeter shell for discharge. Finally, directly hang the ground wire at the grounding end of the discharge rod on the test object.
2. Special attention: Do not directly discharge the ground wire on the shell of the high voltage microammeter, to avoid damage to the high voltage microammeter caused by strong impulse discharge current.
3. Wiring diagram is shown in Figure 4 Schematic diagram of grounding wire for test circuit
