How to remove residual voltage from the cable?

Lida asks:

Good afternoon. Please tell the teapot. The question is: there is a procedure for checking the integrity of the cable core. When the load is disconnected from the core, a residual voltage of about 300V is stored in it. then we connect the "earth" in this vein. The discharge process is up to 2 hours. How to reduce the time to remove residual voltage to a maximum of 30 seconds?

The answer to the question:

Good afternoon. Why 2 hours? Did you measure or why exactly this time?

The capacity discharge rate is determined by the formula:

T = RC

where R is the resistance in the circuit, and C is the capacitance

If you short-circuit the core to ground, then the discharge rate is limited by the resistance of the line, portable ground, and ground electrode. Personally, in my experience, after turning off the power from a long line, we simply short-circuited with portable grounding, having previously connected it to the grounded part and carried out work.

Perhaps I will give a more correct answer if you describe the situation in more detail.

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