What are the correct steps for measuring insulation resistance with HD2705 megohmmeter

Release time:

2023-02-16 09:17

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（1） Before the test, remove the resistance of the tested power cable and all external wires, and discharge them to the ground. The discharge time shall not be less than 1min, and the power cable with large capacitance shall not be less than 2min to ensure safety and accurate test results.
（2） Wipe away the dirt on the power cable terminal sleeve or core wire and its insulation surface with a dry and clean soft cloth to reduce surface leakage.
（3） Place the tramegger in a stable and horizontal position to avoid shaking the tramegger with uneven force during operation, resulting in inaccurate readings.
（4） Under no-load condition, turn the crank of the megger to the rated speed (120r/min) and adjust the pointer to "∞".
（5） For multi-core power cables, the insulation resistance of each phase of core wire shall be tested separately. At this time, connect the outgoing line of the measured core wire to the terminal (L) of the megger, and connect the other core wires to the ground (lead package) and then connect them to the ground terminal (E) of the megger. In order to avoid the influence of leakage current on the insulation surface of power cable, the shake down screen should also be used to knock the wall (G) to completely knock the surface insulation out of the indication of the megger. For the power cable that has not yet been laid, a protective ring can be added on the insulation of the two sides of the tested core wire, and the two protective rings can be connected to the shielding terminal (G) of the megger. For the laid power cable, a protective ring can be added on the sleeves or insulation at both ends of the tested core wire with metal flexible wire, and the protective ring at both ends is connected with the shielding terminal of shake down, while another power cable core is used as the circuit of the shielding wire.

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