electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Longer set screws in the T and some duct seal! (kidding)
Installing a Smaller EMT Conduit Into a Set-Screw Hub of a Larger Size
- Thread starter britcollector
- Start date
- Status
Longer set screws in the T and some duct seal! (kidding)
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I have it! Wrap a strip of metal around the end of the 3/4" EMT until it will barely fit into the T; then tighten the setscrews.
britcollector
Member
- Location
- New York
- Occupation
- Engineer
I solved it. I stuck the 3/4 EMT into the 1-1/4 hub and squeezed the body in a vise until I couldn't move the EMT.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
I hope you're joking!
britcollector
Member
- Location
- New York
- Occupation
- Engineer
I was.... LOL
Oldmaster2
Member
- Location
- PA
- Occupation
- Master Electrician
Use a short piece of conduit with a connector. Install theaded coupling.Put reducing bushing in coupling.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Serious response: get a reducing bushing, either 1-1/4-to-3/4 or 1-1/2-to-3/4, whichever has a large-enough OD, and grind the outer threads off along with enough material to end up with a smooth puck that will just drop in the T-condulet, tighten screws.
Fun response:
"Why don't they make something that will work?"
Fun response:
"Why don't they make something that will work?"
kwired
Electron manager
- Location
- NE Nebraska
Low power control conductors?
kwired
Electron manager
- Location
- NE Nebraska
I was thinking along similar lines, machining something that will fit, could turn the reducing bushing down in a lathe I guess.
1-1/4 bushing should be larger OD than OD of 1-1/4 EMT, once threads are cut off it might be close to same size.
britcollector
Member
- Location
- New York
- Occupation
- Engineer
The supplier of the equipment provided a specification that reads in part: '...each unit requires a dedicated ground back to the facility load center ground buss'. There would be possible warranty issues if I don't comply. I REALLY hate it when a specifying engineer writes specifications without verified justification. I suspect he pulled off of a hospital general spec for an MRI installation or some other sensitive equipment.
kwired
Electron manager
- Location
- NE Nebraska
I might have misunderstood what you have. Apparently is the power circuits to multiple CNC machines. I was thinking wiring within a machine.
That said if using a conduit body instead of pull/junction boxes you might be pulling separate EGC's anyhow because you might not have room to splice them in the conduit body(ies).
MNSparky
Senior Member
- Location
- Minneapolis, MN
- Occupation
- Electrical Contractor - 2023 NEC
I've never seen a EMT to rigid coupling but I guess they are made. Pretty spendy, about $20 per fitting for 1-1/4" from Garvin. Might be more cost effect to go with the male EMT connector to rigid coupling with a reducing bushing in it. Or by the time you're done messing around it might be more cost effective to just replace all the conduit bodies with ones with threaded hubs.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
My suggestion starts with about 90% of that work already done.
Yeah, but where's the fun in that?
synchro
Senior Member
- Location
- Chicago, IL
- Occupation
- EE
A coupling for 1" GRC has a nominal O.D. of 1.53", and the O.D. of 1-1/4" EMT is 1.510".
So if the "T" condulet openings have at least 0.020" clearance for the EMT then a 1" GRC coupling might fit into them. Then you could insert a 1" to 3/4" reducing bushing inside the GRC coupling. You might have to scrape some paint out of the condulet opening, or worst case remove a little metal from the coupling's O.D.
www.alliedeg.us
So if the "T" condulet openings have at least 0.020" clearance for the EMT then a 1" GRC coupling might fit into them. Then you could insert a 1" to 3/4" reducing bushing inside the GRC coupling. You might have to scrape some paint out of the condulet opening, or worst case remove a little metal from the coupling's O.D.
Galvanized Rigid Conduit (GRC) Couplings - Allied Tube & Conduit | Electrical Conduit
Rigid steel couplings are interchangeable with IMC and Rigid (GRC) Steel Conduits and Super Kwik-Couple Conduits.
www.alliedeg.us
britcollector
Member
- Location
- New York
- Occupation
- Engineer
I have a lathe and could turn custom spacers, but I just don't have the time to make 15 of them...and I don't have the room to stack up various fittings to make the size reduction. Anyway, I've ordered threaded type-T conduit bodies and reducer bushings, and will sell the screw type ones I already have for what I paid ($6 each w/covers). Using threaded bodies is the cleanest, easiest way to do it. I was just trying to save a few $.
Thanks everyone for all your great suggestions. I do appreciate it!
Be safe!
Last edited:
kwired
Electron manager
- Location
- NE Nebraska
Sometimes saving a dollar or two cost you ten to twenty more in some other way.
Beaches EE
Senior Member
- Location
- NE Florida
- Occupation
- Electrical Engineer / Facilities Manager
While there are creative ways to solve this one, be mindful of approved uses of fittings, connectors and such and especially of home-made parts. As kwired said, sometimes it's more cost effective to spend a bit more upfront.
- Status