Can you please explain how a defect rectifier can cause extensive DC to flow? A defect rectifier almost always means a short circuited diode, which will increase the AC current, and not cause any DC leakage.

NB! I am an electronic engineer with more than 35 years of experience, I do know what I am talking about.

>A faulty rectifier can give you a DC earth fault.
>
>>>>Earth faults are very hard to find, they come and go, so you have to monitor over an extended period.
>>>
>>>Will do. Thanks.
>>
>>An earth failure will not create the errors in the pictures that you see. The power lines carry AC, which in the event of an earth failure will result in a alternating magnetic field. You will need DC to create a stable magnetic field which may cause the errors you reported.