conduit work

[jay sean]

No wonder no one knows how to bend tube any more, Now when you take your AM2, all the containment is fitted for you, all you do is wire.
I was an apprentice to an 'old boy' he never wanted any slip marks on the tube.
The good old days, were it was it needs to be neat, not 'it will do'.

 

[Engineer54]

American pipe is called EMT and is a lot easier to work with than our galv.

EMT Electrical Conduit – Easy Future Wiring Changes

And it's not a screwed conduit system either, coupling is by means of set screws similar to our now obsolete 1/2'' slip conduit, except it has welded seams... The stuff wobbles around like a good in!! lol!!!

 

[john h owen]

Yes I had a look on U tube on their bending methods they use a hand/foot bender, saw them bend a 90 degrees bend a offset/crankset/bridge.

 

[Engineer54]

Yes I had a look on U tube on their bending methods they use a hand/foot bender, saw them bend a 90 degrees bend a offset/crankset/bridge.

They use electrical or hydraulic bending machines for there galvanised Rigid screwed conduit system, that stuff has a pretty thick wall to it. You may, be able to bend there 1/2'' rigid with a manual bender (equivalent to our old 3/4''/20mm ish) but you'll have problems with the 3/4'' and above sizes... lol!!!

Not a lover of Yank conduit systems, as they tend to use, what i would call hexagon shaped knockout back boxes. To say the installations look cheap and nasty is an under statement They do have proper cast conduit boxes but they rarely seem to use them!!

 

[Top Cat]

Anyone remember aluminium conduit?

It was about in the late 70s early 80s. You had preformed threads, pushed the tube on to the reverse side of the thread and had a "ringing" tool to join the 2 parts together.

Absolutely rubbish! Used it in a school, went back 6 months later and found the kids had had great pleasure in kicking the conduit and flattening it!

 

[HENRY]

to bend to measure[doing it in one length of tube] its about1/knowing your front of bend and back of bend marks .2/accurate measuring3/sliding bevel for your angles,sets.4/ holding tube level in bender when bending.been doing it 40 years old skool jib spark .oh yer and now your mark on former for slippage.

 

[john h owen]

to bend to measure[doing it in one length of tube] its about1/knowing your front of bend and back of bend marks .2/accurate measuring3/sliding bevel for your angles,sets.4/ holding tube level in bender when bending.been doing it 40 years old skool jib spark .oh yer and now your mark on former for slippage.

That is Interesting Henry. So say if you offset for a 20mm galv conduit is 30mm from the back of the saddle to the front of a hole going into a dist board or 50mm from the back of the saddle to the back of the hole in dist board
How would you measure the front and back of the bends, and how would you use the sliding bevel?

 

[john h owen]

Oh and I forgot marking former for slippage

 

[the pict]

I do a bit of refrigeration installation work where the less joints the better, ok its soft copper and fairly easy on the small bore stuff, but I can still end up with what looks like an illicite still I have been shown how to to it but at the end of the day its down to how you can see the final 3D in your minds eye something the girls are better at that the guys, apparently something to do with predatory threat to the young and being able to see all possible ways out, all seems a bit freudian to me
Pict

 

[Knobhead]

As pict said you have to picture the install in your mind.
One of the main things is to sort out the runs first there’s nothing worse than a new install with conduits leap froging over each other.

As for the rest of his post, eeerrm, I’m not to sure!

 

[bugsy]

I have not read all the threads so might be repetative,
Buy a bundle of conduit and hire a Hilmor.
Practice practice pratice and be thankfull no one's kicking your arse every time you mess it up ( although it does speed up the learning process)

 

[the pict]

get some off cut 15 and 22 mm copper from a plumber and practice on that
Pict

 

[mackers]

u seen the price of copper no plumber gonna part with any copper!LOL

 

[snowhead]

Recipe for a Conduit sledge;

2 lengths of galv conduit, black would do tho.

Bends required;

Start from the middle, 2 x 90 bends,

then 2 x 45 (or 135 depends how you view it)

then 2 x 180 so the ends touch between the 90's and 45's

Repeat using other length.

Find the pipefitter, get him to weld them both up.
Leave one with him for his trouble.
Distract joiner, nick some of his offcuts of wood, he can make his own timber sledge, he didn't need us and the pipefitter.

If you could bend a sledge, 1/4" sets on 3/4" tube (yes that long a go) for switch and socket boxes were nothing.

 

[ipf]

u seen the price of copper no plumber gonna part with any copper!LOL

Only offcuts. You could always give it back when you've finished, still the same weight. Not my idea of conduit practice though.

 

[Knobhead]

Copper and conduit, two different animals.
Copper doesn’t spring back like conduit, you have to gauge how much to over bend.

It’s not possible to describe on a forum how to do a set or any bend. It’s one of those things you only learn by doing it.

 

[ipf]

Yep. Practice makes perfect. But once you can handle it you tend not to forget.

 

[fadox21]

Practise makes perfect, if you mess up a bend keep it to the side and you may need it down the line as a off cut save buying a new bundle!

 

[HENRY]

reply to john.bevels useful for mirroring sets on multiple runs and saddle sets;also to find any difficult contours you might have to run tube on.slippage is about accurate bending ;if your bending at say 250mm back bend you want it to come out that way.in order to do this you must know your bender.ie the front of bend mark on the former;there are often half a dozen marks put on the former by previous users on sites.you do a test bend at 250mm ,if it comes out more or less than 250mm ;thats slippage;either allow for it or remark the former accordingley.re your double set its knowing front of bend ,back of bend ;works for me .regards

 

[shanky887614]

No wonder no one knows how to bend tube any more, Now when you take your AM2, all the containment is fitted for you, all you do is wire. I was an apprentice to an 'old boy' he never wanted any slip marks on the tube. The good old days, were it was it needs to be neat, not 'it will do'.

so no one ever showed the trick of file, then treflex wiped with rag on pipe makes it disappear . i remember being shown that trick. i was shown the proper way to bend tube by a plumber during first year off level 2 electrical. im thankful to the college now that made us do lvl1 plumbing as well as electrical. made life a lot easier now that ive started apprenticeship after ive done level3

 

[Billythekid]

Some basics:

For 90 degree bends (back of bend)

Start with a scrap piece of conduit preferably >1m. make a mark at a set distance from end (say 500mm). Put conduit in bender and line up with the start of your former, bend to 90, and remove from bender. Place conduit on floor and measure from back of bend (floor) to the end that you measured from. Say it's 448mm, this will give you a 'take up' of 52mm. Next time you simply add this 'take up' to your required distance, and you should be within a gnats tadger . Would note above only applies if you are measuring from rear of bender (handle end).
If measuring from front of bender make your mark and slide through untill level with back of former + your conduit size (use an offcut of same sized conduit and level if unsure).

For offsets using 30 degree bends

Firstly the multiplier for 30 degrees is 2. So however much you need to offset conduit by, simply times it by two. i.e if you have a 200mm obstruction/level change, mark your bends 400mm apart (200 x 2).

For 45 degree bends just change multiplier to 1.41.

There truely isn't a set of instructions for conduit bending, and as previous members have stated "practice makes perfect". Gain and shrinkage should also be considered, but is often forgotten. hope this helps to reduce your wastage a little.

Kind Regards

Billy

 

[Engineer54]

Sadly a lot of these skills are now dying off. Too easy to buy pre-made bends and angles an just screw them all together, a run comprising solely of bends looks a hell of a lot more professional.

I haven't been on a project for donkey's years now that allowed ''inspection bends or T's of any description (apart from T conduit boxes) to be used in conduit installation. They can rip the cables insulation to shreds. Another thing to remember, every screwed fitting in a conduit run will add a potential snagging obstacle for draw lines and cables alike. They should always be kept to the bare minimum....

Saying that a conduit installation looks more professional with these pre-formed bends etc has to be the joke of the week. They look anything BUT professional!!!
They look what there are, ...a conduit system that's been installed by Amateur that hasn't got a clue about conduit work!!

 

[Silly Sausage]

They look anything BUT professional!!!
They look what there are, ...a conduit system that's been installed by ammeter that hasn't got a clue about conduit work!!

Hardly surprising, currently they're only good for electrical work!

 

[Richard Burns]

Saying that a conduit installation looks more professional with these pre-formed bends, etc. has to be the joke of the week. They look anything BUT professional!!!
They look what they are ...a conduit system that's been installed by an amateur that hasn't got a clue about conduit work!!

I think Strima was agreeing with you and saying that a properly bent conduit system looks more professional than pre made bends.

 

[Engineer54]

I think Strima was agreeing with you and saying that a properly bent conduit system looks more professional than pre made bends.

Didn't come across to me that way, but if i was mistaken then i whole heatedly apologise.

Perhaps i need another coffee this morning, to wake me up... lol!!!