[JimfromSTL]

I recently rewired my basement workshop. I put in a short section of EMT to carry wires from the overhead joist down to a two-gang receptacle box and then out again to second two gang receptacle box. I ran two circuits so I could control which tools were on which circuits more easily.

I wire-nutted all of the ground conductors together (I ran 12-2 NM - probably should not have but it less than 6 feet total and open at the top)... I also pig tailed the grounds to each of the receptacles in both boxes and I pigtailed to a grounding screw in each EMT box.

So besides running 12-2 in conduit (which I found after I did it that I wasn't supposed to), I am curious how best to test that I have properly grounded the EMT.

I run test lite with one prong in the hot slot on one of the receptacles and the other prong touching the junction box. I get a lit (which I expected) but it did not trip the breaker. I would have thought that the prong-connection for the lit tester would have energized the conduit, which was (hopefully) properly grounded, and that would have tripped the breaker.

So (a) should it have tripped the breaker and if it should have (b) is my ground setup incorrect or is my breaker bad?

[Missouri Bound]

A. The breaker should not have tripped. A breaker trips when there is a short or an overload. A test light is neither. All you did was complete a circuit through ground.

B. Your breaker is not bad.

(and running the cable through the conduit is not prohibited, you are merely protecting it.)

[JimfromSTL]

Thanks.

So how do you test to make sure that the grounding will work as needed / expected - in the case the conduit would get energized? I certainly don't want to actually touch the black to the EMT to see if all works - that seems dubious... is there some process or tool you use to validate that if there is a gound fault it actually will trip the breaker?

And separately, I did touch the conduit when I had the prongs connected but no shock - does that mean that the circuit was completing through the ground (less resistance than me)?

[Missouri Bound]

When you say "test light" I'll assume you mean one of those neon type... very small? The current it draws usually won't shock you. You can purchase a plug in type outlet tester. It will indicate various wiring faults, and indiciate when it's correct. You didn't say, but I take it your receptacles are NOT GFCI. If you install those, they have a test button, and they won't work without a ground.

[JimfromSTL]

My tester is a sperry HET 201 vac/dc device with two prongs that lights if a circuit is present - so it probably does not draw much... and I do have a receptacle tester which shows all the correct lights so I do feel that the receptacle (not GFCI but again I think it should be for a basement outletf) are properly grounded (they showed good before I connected the junction box to the common ground and afterwards - so not much help to verify the EMT ground connection)... the EMT starts and stops along my basement wall with no other connection, so I just wanted to make double sure that if the EMT (vs the receptacle itself) were to get energized that it would fault to the common ground I have have connected everything (receptacles and EMT outlet boxes) to and trips the breaker.

[Missouri Bound]

If your boxes are grounded, and the connection between the boxes and the EMT is solid, the EMT is grounded. A short to the EMT will trip the breaker, but a load through the EMT, such as your test light will just energize it. So yes, it is possible that you could energize the EMT without tripping the breaker. This most likely happens when you have a neutral in contact with the ground... this again will NOT trip the breaker. I would replace your receptacles with GFCI and let them offer protection from any ground fault you may encounter. They aren't not that expensive, and it will give you the peace of mind you are looking for.

[JimfromSTL]

Thanks for the info. It helps.