Earth Terminal fault why troubleshoot.

Voltage too high. You can check from the source, the transformer secondary voltage-voltage-voltage electricity devices in the distribution box.

Ground fault. Can also check from the transformer, and then to the power distribution box grounding. The ground to ground, and normal phase grounding fault lines should be excluded. Power outage with insulation or shake tables to measure, segment measurement, try to only segment measured cable, wire, circuit breakers, switches, power supply lines, really difficult to segment the case, unplug electronic devices, sensor device fuses.

Lower grounding resistance of grounding is the key, at the same time greater contact area. Which guarantees a close to the potential of the land as low as possible "zero level", it can avoided Thunder and lightning from the grounding line as you think "crossdress" back into the possibility of power supply circuit. Which can ensure a sufficient capacity to provide a fault current channels, including Thunder and lightning or a short circuit faults, and so on. Because the actual construction process theory is based on contemporary technology and technological change, so this kind of grounding all right, well, remains to be seen how the specifications for the new standard requirements