Originally Posted By: bhendry This post was automatically imported from our archived forum.
Hi Jeff,
That's a great picture - rest assured very educational for many. Thanks.
Here's some info from the SureTest people:
"False Ground Indication
The neutral conductor can only be bonded to the ground conductor at the main neutral buss, where a large copper conductor carries all the return and faulted current back to the earth. Sometimes through error or ignorance, the neutral and ground are connected upstream from the service entrance. This condition is referred to as a false or bootleg ground. Common receptacle testers will test this condition as a normal wiring condition."
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
Jeff,
I’ll give you a little tip…you’ll get that reading sometimes if the outlet is within 15’ of the panel. Don’t know why, but it happens to me all the time.
I see that message, and sure enough the panel is on the floor directly below me or near me somewhere.
Originally Posted By: rzimmerman This post was automatically imported from our archived forum.
kmcmahon wrote:
Jeff,
I'll give you a little tip....you'll get that reading sometimes if the outlet is within 15' of the panel. Don't know why, but it happens to me all the time.
I see that message, and sure enough the panel is on the floor directly below me or near me somewhere.
Keven,
My tester states it detects false grounds with 10' of outlet tested. I always assumed it did a resistance test but not sure. The resistance of 10' of 12g wire is very low.
Jeff,
Great pic. Can I add it to my "What you inspector does not know" list which I give to Realtors?
Originally Posted By: jpeck This post was automatically imported from our archived forum.
It is testing the resistance of the ground, and with no resistance, the ground is likely very short, i.e., a false ground as described above.
However, having a receptacle near (within 10-15 feet) the service equipment (notice that I did not say panel) where the neutral is bonded to ground can sometimes produce sufficiently low resistance to trigger the "false ground" indication.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
to get a correctly wired indication of a 3-prong receptacle with a 2-wire system.
In fact, you should only see 2-prong standard receptacles, or 3-prong GFCI receptacles (marked "No Equipment Ground") on a 2-wire system ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong