Black finish screws used for earthing to metal case.( possibly non conductive)

MisterBill2

Joined Jan 23, 2018
18,568
The reason for doing an actual test instead of an ohm meter test is to verify that the connection can carry some current. And in a real world situation it would verify the integrity of the device safety ground. THAT is the reason that the expensive leakage current testers also provide a ground bond test. But those testers us a lot more than one amp.
AND what sort of bozo would be "exposed to mains voltage" if they were actually qualified to be doing the test at all???
 

MaxHeadRoom

Joined Jul 18, 2013
28,697
The reason for doing an actual test instead of an ohm meter test is to verify that the connection can carry some current. And in a real world situation it would verify the integrity of the device safety ground. THAT is the reason that the expensive leakage current testers also provide a ground bond test. But those testers us a lot more than one amp.
AND what sort of bozo would be "exposed to mains voltage" if they were actually qualified to be doing the test at all???
I have been in the electrical business for several decades and have never seen a HV, high current ground test.
The typical unit used is a resistance Megger, 25/50v, this measure down to very low Ohmic resistance, the very high voltage (500v/1kv) is reserved for insulation resistance test.
https://embed.widencdn.net/pdf/plus/megger/atbsdycpsk/DET3Series_DS_USen.pdf
We always had to use a ground Megger to test actual earth ground resistance back to the grounded supply transformer neutral.
Max.
 
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MisterBill2

Joined Jan 23, 2018
18,568
Well the good news is that a bunch of years back when folks started to be concerned about leakage currents from the mains to different parts of appliances a bunch of companies started selling testers to see just how much leakage there really was. And when that the ird pin came out they added a test to not only verify that it was connected, but that it could carry enough current tester does.teo pop a fuse. And that is part of the test sequence.
Cerainly the megger is a great device for tracking down the fault, but to verify equipment the testers are the best choice.
 

shortbus

Joined Sep 30, 2009
10,045
AND what sort of bozo would be "exposed to mains voltage" if they were actually qualified to be doing the test at all???
AND what bozo would suggest that someone do it in a forum that gets so many inexperienced people on it? I hope you don't think that the presense of a 110V light bulb makes thing safe. But from some of your answers over time you probably do.:(
 
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