- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
That is correct....I can't believe this guy was an electrician.. Are you sure it is not metal conduit all the way?
Garage not grounded
- Thread starter Joey94
- Start date
- Status
That is correct....I can't believe this guy was an electrician.. Are you sure it is not metal conduit all the way?
ptonsparky
Tom
- Occupation
- EC - retired
Yes.
ptonsparky
Tom
- Occupation
- EC - retired
The proper one. Installing a GFCI device would help...it would still hurt, but better than a poke in the eye with a sharp stick.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You do a continuity test to see if the emt is continuous. My bet is something isn't done properly but you could use the emt as the ground if it is continuous throughout. That would be the only reason I can see as to why he didn't run an equipment grounding conductor.
ptonsparky
Tom
- Occupation
- EC - retired
EMT in earth is most likely rotted away if it as been there for any length of the.
So I used two different outlet testers. One shows there is grounding. The other one shows green for a second and than turns red saying there is bad grounding. Also when I plug it in, the light fixture starts making a noise.
The third picture is the connection from the garage to the house. The garage is connected with liquid tight felxible conduit but the junction box is made out of plastic and there is no grounding conductor.
The forth picture is the junction box in which the power comes in from the bottom and connects to the JBox with an EMT.
So my question is how is it possible that one tester shows grounding the other doesn’t ? Never happened to me before.
(I’m thinking that there might me a grounding rod in the soil close to another rod? Maybe the testers have different resistance threshold and one is above, the other under the limit of having the resistance enough to show that it is a bad grounding? I’m not sure how these testers work so I might be totally off about it.)
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
First, forget about ground rods. They have nothing to do with your problem.
Second, tell us exactly how many wires, and what colors, supply the garage.
Second, tell us exactly how many wires, and what colors, supply the garage.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Then you have two individual 120v branch circuits. What you want is one 120/240v MWBC. You have enough conductors to do this, but one of the whites should be green (or bare).
For the grounding to function correctly, your EGCs, boxes, conduits, and ground rods all need to be tied to the service neutral back at the main panel through a grounding conductor.
The amount of current needed to light the lamp in those little testers is quite small. Its possible the crappy ground path through the earth flows enough current to light a neon test light. But it most certainly won't flow enough current to trip a 15A breaker from a 120V source.
A detached structure can have either one branch circuit or one feeder feeding it (see article 225). Two branch circuits is generally not allowed unless they have different characteristics (e.g. one is standby power, a 3-way light switching circuit, or something else you can convince the inspector that it is a different enough characteristics to be separate instead of just a larger circuit). A multiwire branch circuit can be considered one circuit. In the old days when you could recolor smaller conductors, you may have been able to turn two blacks and two whites into a multiwire branch circuit with a separate grounding conductor.
Now, you'd need to remove one of the whites and pull a green in its place, and used a double pole breaker to feed the black/black and white.
A detached structure can have either one branch circuit or one feeder feeding it (see article 225). Two branch circuits is generally not allowed unless they have different characteristics (e.g. one is standby power, a 3-way light switching circuit, or something else you can convince the inspector that it is a different enough characteristics to be separate instead of just a larger circuit). A multiwire branch circuit can be considered one circuit. In the old days when you could recolor smaller conductors, you may have been able to turn two blacks and two whites into a multiwire branch circuit with a separate grounding conductor.
Now, you'd need to remove one of the whites and pull a green in its place, and used a double pole breaker to feed the black/black and white.
Got you! That would be the easiest option. And no extra wire needed in that case. Do you have any idea why would the testers show different results ? If I use a multimeter and connect one lead to my hot and the other to the junction box it does reads 120V. So that should mean there is some kind of grounding already?
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Because you are grounded, but through a high resistance path via the garage ground rod. A digital meter, a neon light, and perhaps an LED light can probably get enough current through the earth to show 120V or light up. Try a 100W incandescent lamp from hot to metal box and see if it lights up (and be careful -- you're energizing all grounded metal parts doing this!). Probably won't light very brightly. An old analog meter or a newer digital one with a LoZ button may not indicate 120V, but can't be sure. It just depends on what the resistance is through the ground rods.
Questions3000
Member
- Location
- Chicago
- Occupation
- Electrician
You can also do a continuity check between your metal junction box and the neutral feeding the garage. If there is continuity and you're getting 120V between the metal junction and your garage hot, then you're grounded. If you're not sure if your garage feed was done in heavy wall rigid or pvc then you can also do a continuity test between both ends of the pipe. Run a piece of scrap wire (you can wire nut together a bunch of scrap wire, so long as it's a continuous path) from one end (pipe going into garage) of the conduit run to the other end (house feed). Strip your wire and clamp onto the pipe feeding said end (house feed). Test the continuity between the wire and the feeding pipe at the other end (garage feed). If you have continuity then it was done in rigid and you're grounded.
Is the conduit run feeding your garage going directly into the electrical panel or is it tapping into a junction box within your house?
If it is going directly into your panel then as others have stated, you can then change your garage feed into a multiwire branch circuit. In this case you'd need to identify the white neutral wire that will now become your new equipment grounding conductor at both ends (garage and electrical) with green tape.
If you're not sure which neutral it is at either end, you can do a continuity test to make sure you're changing over the correct wire. For this continuity test you can turn off one of the breakers feeding your garage. Unscrew the wire from the breaker. Locate the hot in your garage that you turned off (remember this wire). Turn off the OTHER breaker feeding your garage (there should be no power in your garage). Unscrew your two neutral wires from the neutral bus terminal. In the garage, wire nut together one of the neutral wires and the first hot that you turned off (the one I told you to remember) . In your panel, you should now have 2 loose neutral wires and 1 loose black wire. Check the continuity between the black wire and each of the neutral wires. The neutral wire with the continuity (your meter should beep) is going to be your new equipment grounding conductor that you'll be marking with green tape. If you have a grounding bar (that is bonded to your neutral terminal) in the panel then attach that wire to the grounding bar. Reconnect your other neutral wire.
Since this is now a multiwire branch circuit you'll need a two pole breaker for your two garage hots. Don't turn anything on yet, because you still have to rework your neutrals and grounding conductors in the garage. If your garage is run with EMT and metal junction boxes (double check your locknuts and connectors) then you can bond your new equipment grounding conductor directly to the box and your garage should be grounded. You need to separate your equipment grounding conductor from your neutrals in your garage as well. At the first junction box going into the garage from the electrical panel connect all of your white neutral wires together and bond your new grounding wire to the enclosure. It looks like you have a plastic box for your first junction box, so you'll need to do another continuity test (or pull on it and see which one is moving) to identify the neutral wire that you'll be changing into a grounding wire. Grounding wires spliced together and bonded to your metal enclosure. Neutral wires spliced together and kept separate from the grounds.
IF your garage feed is tapped from a junction box inside your house, then the process is the same. Turn off your garage feed breakers. Identify the neutral that will be converted into a grounding wire at both ends. Label said neutral at both ends with green tape. Bond the new equipment grounding conductor to either the metal junction box enclosure (assuming everything is done in EMT) or splice to your equipment grounding conductors within your junction box (If everything isn't done in EMT). MOST importantly, you must now trace back those neutrals back into your panel and rework them within all the junction boxes associated with those circuits. Don't forget to change the garage circuits to a 2 pole breaker.
Those testers are nice in a pinch and great for testing out the outlets you've installed on a job, but they can be unreliable at times. Especially the cheap commercial electric ones. Your multi-meter is your testing tool for troubleshooting.
Dsg319
Senior Member
- Location
- West Virginia
- Occupation
- Wv Master “lectrician”
Didn’t read all the comments as I have a head ache. But from first hand experience do not trust those little gadgets to show wether or not you have a low impedance ground fault path.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If he is using a solenoid tester, or a low-impedance meter, or a voltmeter in parallel with a real load.
Another C10
Electrical Contractor 1987 - present
- Location
- Southern Cal
- Occupation
- Electrician NEC 2020
make sure 1 set blk/wh isn't a switch leg. They use to do that back in the day from the rear porch
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
In the context of this discussion it's key to point out that this only would have been code compliant under old code if the ground rod GEC were connected to the neutral in the panel, and the neutral was bonded to the exposed metal parts/EGCs with a bonding jumper. Otherwise the receptacles will still read open ground. Ground rods do not provide grounding! (Well, they do, but you still read that right.
) However, since there is only a branch circuit and no distribution panel, I don't believe that would ever have been compliant, and the ground rod is also not required in that case.
Seven-Delta-FortyOne
Goin’ Down In Flames........
- Location
- Humboldt
- Occupation
- EC and GC
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
It is if you strip off the insulation at both ends.
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