What Is Megger Test?_
A Megger test, performed with a megohmmeter (often branded 'Megger'), applies a high DC voltage (typically 500–5000 V) to assess the integrity of insulation in cables, motors, and power distribution equipment. It detects moisture, contamination, or degradation that could lead to short circuits or ground faults. The test yields a resistance value in megohms (MΩ), with higher values indicating better insulation health.
Technical Details
The test is conducted between conductors and ground (or between phases) after isolating equipment from power sources. For data-center infrastructure, it is commonly applied to AC/DC power feeds, busbars, and PDU whip cables before energization. Results are compared against OEM-specified minimums or industry guidelines (e.g., IEEE 43 for motors), and a sudden drop from baseline may indicate insulation breakdown. The test voltage must not exceed the equipment’s rated insulation voltage to avoid damage.
How Leviathan Systems Works with Megger Test
During commissioning of GPU racks and power distribution units, field crews perform Megger tests on all incoming power cables and busway connections before first power-up. A failed test halts energization and triggers rework of the affected cable or termination.
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