Does anyone know exactly how the SureTest knows that there is “No Ground” on a circuit? I see this a lot actually and it is sometimes intermittent for example I check the receptacle a second time and there is no indication of no ground. Now if I am on a non-GFCI circuit I test the ground impedance and if is showing greater than 3 ohms. I know the general rule of thumb is less then 1 ohm to protect people and less than .25 ohms to protect equipment.
Is it simply a continuity test to the panel that should be strapped and bonded? In other words by checking continuity between ground and neutral? That does not trip the GFCI but the impedance test does?
I really want to fully understand this. I check voltage drops on my inspections and tag the outlets or “receptacles” of the specific value if >5%. I comment on the <10% drops with a generic explanation of voltage drops, what is and is not required and why they are important, and the ones >10% get a different comment about safety issues when high power demand is made on a lower voltage circuit increasing the current and heat in the wire. I am starting to bring in grounds to the fold and marking those also with a green sticker indicating a ground failure. Often times these are circuits with surge protectors being used and IMO having no ground or a high impedance ground, will negate the ability of a surge protection device to do it’s job. My thought is that often times what the SureTest is getting a high impedance ground and calling it “no-ground” which…might as well be the same right?