Electrical Question

Ted in NE-OH

Well-known Member
I am running a long run of 1/2 EMT with a number of 4in. sq. pull boxes a long the way. Do I need to connect the green ground wire to every pull box when no other connections are being made at the pull boxes?The conduit will be grounded at both ends?
 

I didn't look in the NEC but, no you only need to bond boxes with terminations in them. Do yourself a favor and leave a "loop" in each box anyway. Just in case....

Stan
 
Go with Stan's Idea of 8 inches in each box of all strands. Never have I seen an issue where the extra was a bad thing. Jim
 
While it may have changed since ?? In allllllllll the years in allllllllllll the jurisdictions where I practiced power distribution engineering ANY CONDUCTIVE/METALLIC JUNCTION BOX REQUIRED BONDING TO THE (bare/green) EQUIPMENT GROUNDING CONDUCTOR. With PROPER bonding and jumping and connection methods there are occasions where the raceway might be used as the Equipment Grounding Conductor HOWEVER I was never a fan of such nor did I specify it.

REGARDLESS if its now NEC required or not, I would still bond any conductive/metallic junction box to the Equipment Grounding Conductor to be on the safe side IF REQUIRED OR NOT,,,,,,,,,,, BUT THATS JUST ME yall are welcome to do as you please. Sure it wiLl work if wired that way or not.......


NOTE HOWEVER 1 !!!!!!!!! If there are NO splices,,,,,,,NO internal connections,,,,,,,,NO actual true junction box use (per NEC definitions),,,,,,,,,, perhaps the NEC definition of a JUNCTION BOX may not apply and its ONLY considered as part of the RACEWAY so each box is ONLY part of the raceway and does notttttttttt require each box grounded ?????????????

NOTE HOWEVER 2 The conductive raceway system (conduit and boxes) enclosing conductors DOES ALL NEED BONDED soooooooooooooo if there exists proper low resistance NEC approved connections (requires special terminations/splices etc) so if the boxes are not bonded still the entire metallic raceway system DOES NEED A CONTINUOUS LOW REWSISTANCE CONDUCTIVE PATH and I question if thats the case or not because of all those the box to conduit connections (which MUST be proper and approved???) may not be proper or approved THAT CUTS IN FAVOR OF BONDING EACH BOX but also the conductive raceway system (conduit and boxes) does need bonding SO THE CONNECTIONS FROM CONDUIT TO EACH BOX IN AND OUT NEED TO BE PROPER

NO WARRANTY but I would still bond conductive/metallic junction boxes to the Equipment Grounding Conductor regardless if absolutely required or not I DONT HAVE ANY CURRENT NEC MAYBE SOME KIND GENTLEMAN HERE CAN LOOK IT UP AND CITE WHETHER ITS REQUIRED OR NOT ??????????????? Maybe with NO splices or connections and NO actual NEC defined JUNCTION BOX,, the NEC does NOT require bonding ???? PROVIDED THAT the entire raceway system (conduit and boxes combined) is all properly NEC approved

Where fire and life safety are concerned you may want to consult the NEC and current practicing professional electricians and engineers in addition to anything posted here ME INCLUDED.

Sorry absent any current NEC I cant answer the question but hopefully someone here can look it up and educate all of us, there are some professional electricians on here who are more NEC current than myself SEE WHAT THEY SAY OR CAN LOOK UP FOR US !!!!!!!!!!!!!!!

John T Toooooo longgggggggg retired EE
 
In my pole barn and garages, I first run power to a GFCI outlet, then take power from GFCI to the rest of the outlets.
I'm not an educated EE. I'm not even a licensed electrician. So correct me if I'm wrong, A GFCI will work without a ground wire.

And aren't GFCI required in garages, pole barns, outside outlets??
Other than code, is bonding really that important for 120v?
 
I am renovating an old garage/workshop.A lot of the old wiring was just extension cords to boxes and that sort of mess. Because of the requirement to ground metal boxes I am opting to use PVC and plastic boxes. Ive done this on some other garage type circuits using schedule 80 3/4 PVC because it stays pretty nice and straight. Yes the boxes cost more etc but it makes for a neat relatively dust and moisture resistant installation and I only need to mess with ground wires at devices.
 
George GREAT QUESTIONS heres my rewponse

1) So correct me if I'm wrong, A GFCI will work without a ground wire

A GFCI monitors ONLY the Hot and Neutral conductors by their passing through a Torroid Coil and YES if they are unbalanced by 0.005 amps of fault current it will still trip. It does NOT monitor or measure current in the Equipment Grounding Conductor so YES it can still trip without a ground

HOWEVER ifffffffff the test feature works by shunting 0.005 amps to the EGC and theres no EGC the self test feature wouldnt function.


2) And aren't GFCI required in garages, pole barns, outside outlets?? Other than code, is bonding really that important for 120v?

They are required in garages or pole barns with concrete or dirt floors or outdoors

YESSSSSSSSSSSSSSSSS 120 VAC can kill you dead so proper grounding and bonding is required

John T No warranty Im long retired as a power distribution design engineer but believe this remains true
 
PS in retrospect my best guess NOT researching the NEC is ifffffffffffff the metallic raceway system consisting of junction boxes and conduit ALL PROPERLY BONDED WITH THE RIGHT CONNECTIONS AND TERMINATIONS and ifffffffffff there are no splices inside the boxes and iffffffffffff the system is continuous low resistance, in that case the NEC may NOT require bonding of each junction box to the EGC........

NO WARRANTY PURE GUESS maybe a current practicing professional electrician or engineer can look it up and cite the NEC rules SO WE ALL HAVE THE RIGHT ANSWER versus all our non researched opinions

I would just use (if and where NEC proper) plastic conduit and boxes no worry about grounding or else pull all the way through the conduit no junction pull boxes required

John T
 
If the EMT is installed properly than the NEC allows for it to used as the fault current path in leui of a grounding conductor (green wire in the conduit.) So the answer to your question is that you do not have to ground every box in your run. Now if you are having an inspection than it's up to your municipality and inspector, they can ask for you to go above and beyond code. That said, I've never met an electrician, myself included, that would install EMT conduit without a grounding wire. You're relying on couplings and connectors to make a good connection and carry the fault current, and that's not something that I personally want to depend on. I'd pull the ground wire and at minimum leave a loop in the unspliced boxes like mentioned below. There's also alot more to consider when running EMT, like conduit fill and depending on the number of current carrying conductors, de-rating and properly sizing wire. Best of luck, whatever you do, ensure that it is done safely.
 
Hard bond every box and every device with a ground wire . Using the ground lugs and Mariettes .
Conduit may look good and start out working as a ground system . Do not trust the stuff over the long term .
Do it right and do it now .
Also suspend the conduit and and boxes with three times more clips and screws than required.
I am very tired, still ill , suffering some complications but can not ignore or shut up about electrical safety for you fellows and families .
 
(quoted from post at 14:11:01 01/15/22) Hard bond every box and every device with a ground wire . Using the ground lugs and Mariettes .
Conduit may look good and start out working as a ground system . Do not trust the stuff over the long term .
Do it right and do it now .
Also suspend the conduit and and boxes with three times more clips and screws than required.
I am very tired, still ill , suffering some complications but can not ignore or shut up about electrical safety for you fellows and families .
ood to hear from you. Keep getting better. How many times have all of us seen EMT installations where joints separate? I have seen plenty, myself and could go photograph one right now with wires exposed in the gap!
 
Any boxes with a device require grounding .Box with just a blank cover does not have to be grounded . The green wire will still make contact with several places in the run.
 
Glad you are getting after it. I don't get down very often and the last time was a 3 day stint in the hospital for a antibiotic reaction.
It drove me crazy. I imagined it to be like being in jail....having never been there but imagined. Hang in there and get well. We
miss you.
Mark
 

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