As the internet gets ever more frustrating to use, mostly coming up with superficial rubbish, it’s an absolute delight to find real, proper, helpful information presented in such a clear and concise manner. I have never seen a more thorough and engaging presentation. I’m watching all your videos - no need to go anywhere else!. Thanks.
I’m learning about steel conduit to be able to run data cabling for CCTV on industrial sites and I already know before watching this video from John’s past videos this is going to be extremely useful. Thanks in advance John 👌
No. Stop. I missed the first 30 seconds of the intro because I was laughing so hard at the cute minions t-shirt. Love your videos and love The dry humour :-)
Hi John, This takes me back to my apprenticeship when the conduit was 1 and 3/4 inch then they changed to 25 and 20mm. I remember bending the conduit using me knee or a length of timber with a hole drilled in it. Then the boss got a bending machine...good times. Copper piro was also a good product but too expensive now. Thanks for you videos. Cheers Dave.
Great video, this brings back memories of threading running couplers on 25mm pipe as a first year apprentice-seeing a yellow Hilmor bending machines still causes flashbacks..
I find using a vacuum cleaner with some flex conduit taped in the end can pull a string through to pull cable. Also can use if drilling through a box want to vacuum the mess as you do.
I'm seeing a lot of comments on US conduit properties which are pretty inaccurate. Here are some common specs for US conduit types: 3/4-inch EMT (21mm inside diameter) Nominal wall thickness 0.049 in., 1.25mm (tubing is not allowed to be threaded) 3/4-inch rigid conduit (21mm inside diameter) Nominal wall thickness 0.107 in., 2.72mm (threaded with tapered threads) Neither of these are bendable with bare hands unless you're really, really tough. For EMT trade sizes up to 1-inch and rigid trade sizes up to 3/4-inch, we generally use a hand bender. Above these sizes there are hand-powered benders, electric benders and hydraulic benders. US practice would be to avoid the combination of bushing, coupling (coupler) and threaded conduit to minimize the number of joints when using the conduit as a ground fault path. We would typically use two lock nuts on boxes with knockouts, one inside, one outside the box to attach the conduit to the box, and a plastic or malleable iron bushing inside the box to cover the end of the conduit and prevent damage to wires. Cast boxes will be similar with factory threaded (tapered) entries. The tapers on the male and female threads form a pretty liquid--tight connection. Set screw connected conduit has a very long tradition, and if installed properly can maintain ground continuity for a very long time especially when steel connectors and couplings are used (versus the zinc fittings which were very popular back in the 70s and 80s). That being said, it has become common practice to pull a separate ground conductor through conduit and not to rely wholly on the piping system for ground faults. This doesn't eliminate best installation practices required for installing conduit with set screw connectors and upon installation the conduit system must perform properly as a grounding conductor. In general, metallic conduit is much more common in the US and Canada than in Europe and the installation of conduit here requires a more advanced level of craftsmanship than outside the US and Canada. Guys who do it often have really turned it into an art form.
Thank you. Love the Show, but 25 years of dealing mainly with Rigid, I was nonplussed when John was acting like America is wired with EMT. There's also IMC, but we didn't use it. Our stuff was mainly in a Class I Division 1 area, so even the Conduit Fittings had thread on covers. Most of our stuff was clad with heavy vinyl like covering for corrosion resistance, but some Stainless Conduit existed in the facility. Thanks for the thorough explanation of the various U.S. Conduits.
To find it the point for certain, measure the amount you need and mark the conduit then bend it at that mark and measure how long it actually came out, next bend subtract the amount of extra for the next bend and it will come out exact, I have used many different types of benders and they are all a bit different as well as the dies used but my method will give you 1 pipe that will need to be cut for the first bend on the end of the pipe and after that you will know exactly how much you need to remove from the next bends to be exact with no wastage.
Great video. What would be great gangs to install on brick wall. Looking for something that won’t go into plaster. I didn’t know what would look nice but be suitable for project. Thanks
This might be answered in a future video but how often is the earth wire attached to the conduit? After a certain distance? Every time the cable is broken out/terminated?
I was glued to this vid from start to finish. Is thete a special tool for tightening the milled nuts like the one you used for the hexagonal ones? Thanks for sharing.
Just about the only time we used a "slip ring" was when we needed ti join to conduits together that were both bent! Simply threading the length of the coupler and ring on one conduit, run the "slip ring" and coupler onto the conduit, offer the two conduits together and thread the coupler over the second conduit tightening the first conduit with the ring! If you needed a Box to be at the right angle to a tube when tight simply try it first and if the box is too far to make it , note the angle it is off and run the die back to the end plus the required angle! We also never used the conduit as an earth but ran a dedicated earth wire! This meant that 1. you did not have to have a lower resistance path because the conduit is steel and the wire copper and 2. When the conduit deteriorates you do have an effective earth path! .... Obviously we earthed the conduit at each light / socket / switch point ;0)
Re the rusty thread, surely this would hinder a good earth connection. Is it the done thing to clean the thread with wire wool or similar then coat the thread with a light grease? Great explanation thank you.
No, normally you cut the thread and then connect it immediately. That one is only rusty because the conduit was supplied with it from the factory and it got left outside in the rain. Rusty bits should be cut off and a new thread done.
Yeah, huge difference between EMT and rigid conduit. Interesting that British sizing is for the OD, not the ID. Trade sizes in the US specify the ID and, unlike US lumber, the actual ID is slightly larger than the nominal value. So-called 1/2" conduit has ID ~0.74" and 3/4" has ID ~0.95". Are the UK threads straight or tapered? The handles on that diestock are pretty small for the size.
Threads are parallel. Conduit has always been sized on the OD. However steel pipes for water or gas (and the fittings that are used with them) are still sized on the ID in inches, even today with most everything else being metric.
@@jwflame Very interesting. US rigid conduit still uses those inch pipe sizes and tapered threads. The tapered threads are a pain for aligning bends-the jam nut you show is going to be much less trouble.
@@PaulSteMarie I think it's the same with garden hoses and fittings as well. In the UK, the threads are straight, whereas in the US I believe you have tapered threads.
Nothing like doing the first fix and then going back to pull the cables only to find the plasterer has filled your boxes full of muck and the plumber has gone through your conduit with a hole cutter....
JW, as always, thanks for your videos, very helpful content. I wanted to ask, can the galvanized steel conduit be used externally? I ask because it does not look like the boxes will be waterproof when you screw a flat top on them? Thanks
i have threaded plenty of conduit for internal work galv conduit is a total waste of money black enamel was allot easier to thread but that was them good old days . but think 18 edition wiring regs are with us metal consumer units plastic conduit could collapse in a fire oh dear , the metal clad system is back . a swan neck bend was the practise piece for a beginer in con duit or two u shaped bends with running couplers i made a right mess of mine . john thank you for these videos you are a person with in depth knowledge . ? the iee used to have lecture nights held around the country to explain things in yours and my terms a bit like the christmas lectures on television i went to two very very good iet now what do these people offer if dont they should . thank you john
@@jwflame Not sure if I'm reading this right but RS seem to be offering 20mm at £2.47/metre while galvanised is £2.58/m. The snag might be that it's listed as 'back order, dispatch when available' so the price might be a for a product that never appears. :) And even so I see offers online for galvanised that are half either price so assume that RS price is well above what would be found at trade counters. Curious memory, black enamel was used throughout the 'new' building at school which was erected 1970-72. Very smart it looked too.
I use wd40 spray or tapping spray when threading metal conduit. Bahco holesaws seem the best for drilling out the backs, it's handy to make a wooden block to secure them instead of drilling between your feet on the floor
@@andrewwallace73 as far as I can see it isn't directly for electrical or building regs purposes but makes it much easier to achieve and maintain hygiene regime required by food standards. For the same reason it's usual to use fixings with extended stand-offs to make it possible to clean behind pipes and conduits.
Hi, where is it legally required in Uk and what installations is it just advisable? Appreciate the factual presentation in contrast to US self promotional vids.
I think it is the company's who are insuring the buildings choice, i did hear of a case where they would not insure the house (thached roof) if the wiring in the loftspace wasnt in steel conduit.
this is complicated work. you can't atach the boxes o the wall untill you finish all circuit. because you can't twist the box on the wall with a conduit atached to the wall. that's why they have the "nasty" way of connecting them.
I have sold conduit systems for over 2 decades and John’s information is quite interesting but makes a number of glaring mistakes in terms of his explanations of certain things, as for his comments on Conlok his knowledge of the product is frankly weak and extremely misinformed.
Steel conduit is much stronger than plastic and is mostly used in industrial situations, plastic conduit would be too easily broken for use in such places.
Sometimes it is necessary. Here in Germany we use such a system to create installations which are vandalism proof. The conduits are stainless steel. The connections are different, here the connections between pipes are not screwed, they're crimped the same way like water pipes (copper or stainless steel). In standard installations we use plastic conduits. The other application where you can use this is your installation is outside and exposed to direct sunlight. Plastic would become brittle over the years. But then you must use water tight variants rated at least IP54.
As the internet gets ever more frustrating to use, mostly coming up with superficial rubbish, it’s an absolute delight to find real, proper, helpful information presented in such a clear and concise manner. I have never seen a more thorough and engaging presentation. I’m watching all your videos - no need to go anywhere else!. Thanks.
62k subscribers, Holly smoke...
Well done and of course we'll deserved. My favourite channel.
I’m learning about steel conduit to be able to run data cabling for CCTV on industrial sites and I already know before watching this video from John’s past videos this is going to be extremely useful. Thanks in advance John 👌
No. Stop. I missed the first 30 seconds of the intro because I was laughing so hard at the cute minions t-shirt. Love your videos and love The dry humour :-)
John's straight face and his hilarious shirts always make me giggle like a school girl.
I've heard John fancy's school girl...
Hi John, This takes me back to my apprenticeship when the conduit was 1 and 3/4 inch then they changed to 25 and 20mm. I remember bending the conduit using me knee or a length of timber with a hole drilled in it. Then the boss got a bending machine...good times. Copper piro was also a good product but too expensive now. Thanks for you videos. Cheers Dave.
Don't forget to mention that with legacy conduit installations the boxes have 2BA threads, which is a larger thread diameter than M4.
Great video, this brings back memories of threading running couplers on 25mm pipe as a first year apprentice-seeing a yellow Hilmor bending machines still causes flashbacks..
Fortunately my bending machine isn't yellow. instagram.com/p/BX8Qa_Nj8Xl/
I was just about to say the self same thing LOL
That's one swanky bending machine :)
I find using a vacuum cleaner with some flex conduit taped in the end can pull a string through to pull cable. Also can use if drilling through a box want to vacuum the mess as you do.
Exalent vid as per with all John's vids.. & top tee-shirt very informative look forward to next part thank you
I'm seeing a lot of comments on US conduit properties which are pretty inaccurate. Here are some common specs for US conduit types:
3/4-inch EMT (21mm inside diameter) Nominal wall thickness 0.049 in., 1.25mm (tubing is not allowed to be threaded)
3/4-inch rigid conduit (21mm inside diameter) Nominal wall thickness 0.107 in., 2.72mm (threaded with tapered threads)
Neither of these are bendable with bare hands unless you're really, really tough. For EMT trade sizes up to 1-inch and rigid trade sizes up to 3/4-inch, we generally use a hand bender. Above these sizes there are hand-powered benders, electric benders and hydraulic benders.
US practice would be to avoid the combination of bushing, coupling (coupler) and threaded conduit to minimize the number of joints when using the conduit as a ground fault path. We would typically use two lock nuts on boxes with knockouts, one inside, one outside the box to attach the conduit to the box, and a plastic or malleable iron bushing inside the box to cover the end of the conduit and prevent damage to wires. Cast boxes will be similar with factory threaded (tapered) entries. The tapers on the male and female threads form a pretty liquid--tight connection.
Set screw connected conduit has a very long tradition, and if installed properly can maintain ground continuity for a very long time especially when steel connectors and couplings are used (versus the zinc fittings which were very popular back in the 70s and 80s). That being said, it has become common practice to pull a separate ground conductor through conduit and not to rely wholly on the piping system for ground faults. This doesn't eliminate best installation practices required for installing conduit with set screw connectors and upon installation the conduit system must perform properly as a grounding conductor.
In general, metallic conduit is much more common in the US and Canada than in Europe and the installation of conduit here requires a more advanced level of craftsmanship than outside the US and Canada. Guys who do it often have really turned it into an art form.
TIL NEC only requires a separate grounding conductor in EMT or conduit for health care facilities.
Thank you. Love the Show, but 25 years of dealing mainly with Rigid, I was nonplussed when John was acting like America is wired with EMT. There's also IMC, but we didn't use it. Our stuff was mainly in a Class I Division 1 area, so even the Conduit Fittings had thread on covers. Most of our stuff was clad with heavy vinyl like covering for corrosion resistance, but some Stainless Conduit existed in the facility. Thanks for the thorough explanation of the various U.S. Conduits.
Great, comprehensive intro to the subject. Thanks!
Any chance please JW you can do a video about how to measure to bends etc and how to finding bending point on conduit bending former please
Yea if you could JW that would be handy👍
Please do this would be very useful.
Yes pls mate I'd appreciate that aswell
To find it the point for certain, measure the amount you need and mark the conduit then bend it at that mark and measure how long it actually came out, next bend subtract the amount of extra for the next bend and it will come out exact, I have used many different types of benders and they are all a bit different as well as the dies used but my method will give you 1 pipe that will need to be cut for the first bend on the end of the pipe and after that you will know exactly how much you need to remove from the next bends to be exact with no wastage.
Mentorcase Thanks for that bug I’m sure a lot of people prefer to see/watch than reading to pick it up quicker
12.26 I’m impressed. This great tool .. and yet I’ve seen John tighten screws with the end of a pair of pliers. 😐 Love you, John!
Loving that shirt John!! 😍
Great video. What would be great gangs to install on brick wall.
Looking for something that won’t go into plaster. I didn’t know what would look nice but be suitable for project. Thanks
Thank you for excellent video.
Fantastic video!
Here in the United States we use 6/32 screws for switches and receptacles, and 8/32 screws for light fixtures. The screws have 32 threads per inch.
Excellent video, Dr. Nefario, thank you ;-)
This might be answered in a future video but how often is the earth wire attached to the conduit? After a certain distance? Every time the cable is broken out/terminated?
Thanks a very useful instruction.
Female bushes are used on control panels used on machines in factories and so on.
Thanks for sharing.
this is probably equivalent to Intermediate Metal Conduit or Rigid metal conduit in the US.
I was glued to this vid from start to finish. Is thete a special tool for tightening the milled nuts like the one you used for the hexagonal ones? Thanks for sharing.
john will you soon make a video about flexi conduit and the accesories involved in using / installing
Are conduit boxes fixed to the wall? There doesn't appear to be any fixing points?
They are screwed to the conduit, the conduit is fixed to the wall.
Thanks John
Just about the only time we used a "slip ring" was when we needed ti join to conduits together that were both bent!
Simply threading the length of the coupler and ring on one conduit, run the "slip ring" and coupler onto the conduit, offer the two conduits together and thread the coupler over the second conduit tightening the first conduit with the ring! If you needed a Box to be at the right angle to a tube when tight simply try it first and if the box is too far to make it , note the angle it is off and run the die back to the end plus the required angle! We also never used the conduit as an earth but ran a dedicated earth wire! This meant that 1. you did not have to have a lower resistance path because the conduit is steel and the wire copper and 2. When the conduit deteriorates you do have an effective earth path! .... Obviously we earthed the conduit at each light / socket / switch point ;0)
Nice shrirt very informative. Thanks
John should be a college lecturer
Golden 👍
will those bush wrenches do the locking nut/ring for swa glands too?
Would be interested to see part 3…….
Re the rusty thread, surely this would hinder a good earth connection. Is it the done thing to clean the thread with wire wool or similar then coat the thread with a light grease? Great explanation thank you.
No, normally you cut the thread and then connect it immediately. That one is only rusty because the conduit was supplied with it from the factory and it got left outside in the rain.
Rusty bits should be cut off and a new thread done.
@pmailkeey czcams.com/video/tdQKskNMNbw/video.html
Seriously cool stylin bro ;-)
Any reason for the brass screws?
Peter Hurst. So they dont rust and bind in the thread.
Joseph Nicholas is that the same reason for coming back to metal CU because they are a 1000 years old?
Yeah, huge difference between EMT and rigid conduit.
Interesting that British sizing is for the OD, not the ID. Trade sizes in the US specify the ID and, unlike US lumber, the actual ID is slightly larger than the nominal value. So-called 1/2" conduit has ID ~0.74" and 3/4" has ID ~0.95".
Are the UK threads straight or tapered? The handles on that diestock are pretty small for the size.
Threads are parallel. Conduit has always been sized on the OD. However steel pipes for water or gas (and the fittings that are used with them) are still sized on the ID in inches, even today with most everything else being metric.
@@jwflame Very interesting. US rigid conduit still uses those inch pipe sizes and tapered threads. The tapered threads are a pain for aligning bends-the jam nut you show is going to be much less trouble.
@@PaulSteMarie I think it's the same with garden hoses and fittings as well. In the UK, the threads are straight, whereas in the US I believe you have tapered threads.
Nothing like doing the first fix and then going back to pull the cables only to find the plasterer has filled your boxes full of muck and the plumber has gone through your conduit with a hole cutter....
What's the advantages of metal conduit over SWA/Armoured cable?
Metal Conduit is far tougher than steel wire strands wrapped around cable. It also won't degrade due to UV light like plastics may.
Do people bury conduit in walls? I’ve only ever seen in factories/workshops and occasionally domestic outdoor wiring.
Yes, very common in older apartment buildings / flats.
JW, as always, thanks for your videos, very helpful content. I wanted to ask, can the galvanized steel conduit be used externally? I ask because it does not look like the boxes will be waterproof when you screw a flat top on them? Thanks
Yes, it can be used externally. Rubber gaskets are used to seal between the lid and the box, www.yesss.co.uk/circular-conduit-box-rubber-gasket
@@jwflame ahh yes thank you, obvious really, I should have checked. Thanks for your response, and keep up the good work with the videos.
Can you use the steel conduit outside into a light (side entry) using just a Bush and coupler? I don’t see how it’s ip rated against rain?
Definitely no IP rating with metal fixtures and components. That's what you see with plastic parts.
What is meant by class 1,2, 3 & 4 in steel CONDUIT (BS 4568) , Is this specification still in use?
That standard was withdrawn years ago. The classes referred to the protection of the steel, such as primer, enamel paint or zinc galvanising.
What about stainless steel I’ve put it in a school kitchen
Wiring minions. Making more CNC stuff?
6.24 wow! Are you sure you have enough of those screws?
6:24 - How many lids could he fit with those? I'm guessing 100 perhaps.
Are you, John, wearing your pyjama?! :D
i have threaded plenty of conduit for internal work galv conduit is a total waste of money black enamel was allot easier to thread but that was them good old days . but think 18 edition wiring regs are with us metal consumer units plastic conduit could collapse in a fire oh dear , the metal clad system is back . a swan neck bend was the practise piece for a beginer in con duit or two u shaped bends with running couplers i made a right mess of mine . john thank you for these videos you are a person with in depth knowledge . ? the iee used to have lecture nights held around the country to explain things in yours and my terms a bit like the christmas lectures on television i went to two very very good iet now what do these people offer if dont they should . thank you john
Black conduit was cheaper in the past, but now it's rather difficult to find and is either the same price or more expensive than the galvanised.
@@jwflame Not sure if I'm reading this right but RS seem to be offering 20mm at £2.47/metre while galvanised is £2.58/m. The snag might be that it's listed as 'back order, dispatch when available' so the price might be a for a product that never appears. :) And even so I see offers online for galvanised that are half either price so assume that RS price is well above what would be found at trade counters.
Curious memory, black enamel was used throughout the 'new' building at school which was erected 1970-72. Very smart it looked too.
Conduit 101
I use wd40 spray or tapping spray when threading metal conduit.
Bahco holesaws seem the best for drilling out the backs, it's handy to make a wooden block to secure them instead of drilling between your feet on the floor
When I was an apprentice we used Starrett holesaws, and Temaxol cutting compound.
good video, my request pls add meterial names on next upload videose sir,
Sure,,
What about hospital saddles
Much more robust and less plasticy than our arrangements in the US...
Suggest more muted, plain, less gaudily-decorated wardrobe in future?
OMG... EMT is so much easier to use!
It is important to use pipe dope on threads otherwise electricity will leak 😂
In the us they call steel conduit rigid conduit.
What about stainless steel conduit?
It exists, and is very expensive compared to galvanised steel.
@@jwflame Do you know if it's compulsory in comercial kitchens?
@@andrewwallace73 as far as I can see it isn't directly for electrical or building regs purposes but makes it much easier to achieve and maintain hygiene regime required by food standards. For the same reason it's usual to use fixings with extended stand-offs to make it possible to clean behind pipes and conduits.
Hi, where is it legally required in Uk and what installations is it just advisable? Appreciate the factual presentation in contrast to US self promotional vids.
Im sure the lighting has to be in metal conduit if the building has a thatched roof.
Legally required - probably nowhere, but there are many situations where it is desirable or even essential.
I think it is the company's who are insuring the buildings choice, i did hear of a case where they would not insure the house (thached roof) if the wiring in the loftspace wasnt in steel conduit.
Usefull in workshop or garage instalations.
Paul F plastic is good enough for most workshops.
I'm surprised that these old slotted screws are still being used after all this time.
>
this is complicated work. you can't atach the boxes o the wall untill you finish all circuit. because you can't twist the box on the wall with a conduit atached to the wall. that's why they have the "nasty" way of connecting them.
I am that moron
Wire whool
wollywotsit Whollywhotsit?
COOL WHIP ;)
whire whool
Lol stewey
I have sold conduit systems for over 2 decades and John’s information is quite interesting but makes a number of glaring mistakes in terms of his explanations of certain things, as for his comments on Conlok his knowledge of the product is frankly weak and extremely misinformed.
Do elucidate!
I think the closest thing we have here in Amerikkka would be called IMC which has a thinner wall thickness than rigid conduit.
I wonder if JW ever laughs
Perhaps.
twitter.com/group_e5/status/1121878173241810945
never take any notice of anyone who spells wire wool,as whire wool
I’m not having a go but I’m pretty sure your not a Sparks. I could pick it apart but I won’t.
Oh come one, give it a go. Doubtless everyone would benefit from your critique.
I'm assuming you are superstitious..
First
Don't use this metal conduit anymore. It was the standard 1,000 years ago before plastic was invented. Same goes for plumbing.
Steel conduit is much stronger than plastic and is mostly used in industrial situations, plastic conduit would be too easily broken for use in such places.
In the us they use it for underground piping in commercial buildings.
Sometimes it is necessary. Here in Germany we use such a system to create installations which are vandalism proof. The conduits are stainless steel. The connections are different, here the connections between pipes are not screwed, they're crimped the same way like water pipes (copper or stainless steel). In standard installations we use plastic conduits.
The other application where you can use this is your installation is outside and exposed to direct sunlight. Plastic would become brittle over the years. But then you must use water tight variants rated at least IP54.
Excellent points. I was referring it to DYI stuff in general. I would point out that steel conduit does tend to rust over time even galvanized.
We've installed a fence and doors 20 years ago which are made of hot-dip galvanized steel. No rust until now.