Due to demolition or relocating conduit I probably removed hundreds of ground screws that myself or dedicated co-workers installed and never came across one loose listed green screw that connected a ground wire to the threaded hole in a 1900 or 2100 box. Tried to always ask for ground screws with a hex head so we could use a nut driver to get them tight. Have done work in a lot of machine shops, tool & die shops, injection molding plants and places that had large machinery and found at least triple the amount of loose cover screws in those places then in drop ceilings of offices & stores. I made up a temporary power take off to use while replacing or upgrading services. Had a 30' long cord with alligator clamps to a 1900 box with two GFCI receptacles and an in line fuse holder. The cord got tossed around sitting in my van and cover screws would come loose. Installed #8 lock washers on the two cover screws and might have taken a year or two and they came loose. I stored the cord under a shelve in the van because it was more practical then hanging it on something tio only get in the way.
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- Thread starter Jpflex
- Start date
Retired and not sure if still made but one supply house sold 1900 covers for devices that were painted with a light gray paint that at a distance looks like regular bare steel covers. So to my thinking painted surface would not provide a reliable ground path especially during a short. Another reason I always ran a copper ground wire spliced to ground wire in conduit or MC cable then to box ground screw.
Rick 0920
Senior Member
- Location
- Jacksonville, FL
- Occupation
- Electrical Instructor
Many reasons. Loose screws. Someone removing the cover and then the device is no longer grounded. The things that I do that are above minimum standards are usually based on cost and time involved. If it's pennies to do and takes a few seconds extra, I'm doing the better practice. It has nothing to do with is it adequate. It's just a better installation IMO.
Greg1707
Senior Member
- Location
- Alexandria, VA
- Occupation
- Business owner Electrical contractor
What do mean about installing the cover upside down?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
I don't understand why, and I'm skeptical that, all these cover screws are spontaneously loosening up
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
If you remove a raised industrial cover, the receptacle comes with it. Also, if you are removing this cover you should have the power off and it doesn't matter if the device is grounded. Plus, you wouldn't have anything plugged in if you have the cover off.
Covers with a slot that are usually at a 45 degree angle from top of box. If installed slots facing up and screws come loose cover can fall off. Found it several times on flat covers where you open up a ceiling title and a cover drops to the floor belief exposing an open 1900 or 2100 box.
In deeper 1900 & 2100 boxes have seen as many as 6 separate circuits shoe horned into the box . Unplugging something especially a computer while opening a cover to check on adding a tap off is not allowed . Qualified worker wearing g proper PPE should be allowed.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
Am I understanding correctly that you are saying it is typical to leave a device energized and plugged in while removing the cover to look inside the box? If so, so what if the EGC path is broken for a few minutes? IMO if you are going to work on it hot, it's safer to have the cover isolated from ground.
For every "better" we can just go up the chain to another point and then what? For example, if using a ground wire instead of relying on the box is better, then what if the ground wire is loose? And if you use loctite on the ground screw, what if there is no MBJ at the panel? And if you exothermically weld the neutral to the EGC, what if a squirrel chews through the neutral? And if you genetically engineer a virus to kill all squirrels, what if it mutates and I miss the St. Patty's Day parade in Savannah in 2020?
Down here on planet Earth it sure is easy to come up with wacky what-ifs that most likely no one will ever see.
Down here on planet Earth it sure is easy to come up with wacky what-ifs that most likely no one will ever see.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
You've already missed it. You would have to have the squirrel mutate into a time machine to go back to 2020!
Problem I run into was the the fire / alarm tech would install a wall wart that screws onto the outlet box using that middle screw.
Then when someone bumped it and broke the tab on the wal wart it the receptacle is completely loose in the mulberry cover and short out.
They did change the design of the covers so now they take 3 screws instead of one, but I still see lots of the old ones in the wild or people just ignore the outer two screws.
Many of them have now eliminated the middle screw altogether, so now there is no choice but to use the outer screws.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
Wow, rough day at work today. Came in this morning and all the 4sq covers all loosened up and were laying all over the floor.
- Occupation
- Licensed Electrician
Maybe use half phillips head screws and half slotted in the boxes and see if one is more apt to loosen up over time.
I wss an electrician for 50 years and we always installed a ground wire to receptacles mounted on 1900 or 2100 covers. Most of the boxes that I opened were the same way. Being the ground is only used during a short circuit or a down stream appliance, machine etc grounds out so for the very short time we were not overly concerned over losing s ground.. Over the years with more computers and electronics it can take up to several days get approval for a 5 minute shut down. At a.large Research they started having shutdown meetings at least four months for mandatory extended three year switchgear & large ( over 400 amp ) rack out circuit breakers testing & cleaning. Of course a week before set in stone entire Saturday night shutdown several departments wanted shut down moved back. Several times on feeders or circuits 400 amps & lower we would splice in SER cable to an energized equipment that company said could not be shut down. After tying in the phased out cable we would cut the existing wires to reroute conduit.