3phase industrial - clear a couple of things up?

[screech]

Hey guys, first post here so please go easy

Iv just started this job, helping a mate of mine, whose mate has brought a unit that needs fitting out.

Il try and paint a picture for you...

Its the middle of 3 units, that was knocked into 1, but now been bricked back up into 3...

Apparently it was all wired as one so when they bricked it up they just cut through it all.

Its had a new supply put in, and a 6way 3phase proteus board put in.

Above the ceiling i found a coiled up 16mm T+E that went off to a Single phase 6way board that feeds the upstairs warehouse lighting and the small office lighting and power.

Off the 3phase board comes one 6a mcb feeding the downstairs warehouse lighting (Grid ceiling with flexed lights)

He wants a load of power put in downstairs around the warehouse, a few sockets upstairs, roller shutter powered up at the other end of the unit (55m run) and the unstairs office area lighting will need re-wiring as the asbestos ceiling is going to be ripped out!

Now just want to clear a couple of things up, if possible.

Does everything have to be RCD protected. As its a 3 phase board i dont want to just put an RCD mainswitch in because of lighting!
Im thinking of putting RCBOs on everything, but obviously that the more expensive way of doing it.

I dont really touch on industrial much, and when we do the lighting doesn't get RCD'd, but in my understanding, isn't that wrong?


What would you do?
Ohh dear, sorry i seem to have written quite a lot there! Thanks for reading and i hope you can give some ideas.

Cheers

 

[Darkwood]

Rcd protection is only required if cables are hidden below building surface materials and not mechanically protected but usually industrial is surface steel conduits or trunking thus rcd wouldn't be required so it depends on installation methods

 

[screech]

Thanks for the quick response.

Cables will be clipped above the susspended ceiling, then dropped down in tube to the outlets.

To get the the upstairs office area existing cables go up a boxing.

The 3phase roller shutter is going to be swa cleated along above the ceiling also.

Thanks for the advice

 

[Darkwood]

Thanks for the quick response.

Cables will be clipped above the susspended ceiling, then dropped down in tube to the outlets.

To get the the upstairs office area existing cables go up a boxing.

The 3phase roller shutter is going to be swa cleated along above the ceiling also.

Thanks for the advice

Just remember if any wires are unprotected in the offices under plaster then rcd protectection is needed so check the wiring to the switches and also metal capping wont suffice as protection.

 

[Spudnik]

Probably best to RCD the socket outlets.

 

[screech]

I will be rcd'ing all socket outlets anyway.

Don't see why I need to on the roller shutter?

Everything in the toilets will be.

So it's just the lights, it's all stud wall, but il come down surface in tube then I'm all good.


Cheers

 

[Spudnik]

Sounds good, but like you say, i dont see any reason to RCD the roller door, if its all surface run and on its own radial.

 

[screech]

Thats what i thought.
Just been to get the breakers, didn't realise how expensive RCBos are!!!

Iv decided to change the single phase CU to a duel split load, that way i can run the cables up how i like and put the switch drops in the stud wall. If he doesn't want to pay for that then will he want to see loads of tube!!

cheers

Well just been there again and had another look above the susspended ceiling, clipping up there is going to be inpossible, its all criss cross metal work!

Dont think i wanna just throw cable above there, gonna have to have a think on that one!

 

[Sintra]

Run them in some cable tray or basket.

 

[apprent10]

Hi fellas. First of all, what a great site! Found it just through a google search!

I am an apprentice working for a firm in Sussex.

This topic is similar to the job i have been put on this week.

The electrician and i have been given the task of wiring some lighting and power supplies in an office.

The office has a false ceiling, the 600x600 grid type.

We have been told to throw the cables over the grid, no tray or anything (theres nothing really up there to tie or fix anything to anyway!)

I was just a little concerned about this, not that its my problem, im just learning, but is this in any way against the rules/regs??

Many thanks.

 

[bugsy]

I'd only rcd the sockets, tray and basket / swa / run FP200 or equiv. on tray above offices to lighting mashalling boxes , flex out to luminaires don't forget the em's

 

[apprent10]

Hi, thanks for the reply!

Yes the sockers are down to be on RCD.

We've been given T+E to wire to everything, to boxes for lights where flexes will be brought out of, and to where the socket drops are, will enter tube.


thanks

 

[bugsy]

How do you intend to protect the T & E this is an industrial unit - what's going to be used for?

 

[apprent10]

Thats what i thought would be said tbh. I cant have a say in this, im 'just the apprentice. (lol!)'

As far as i can tell, they are just planning on having the T+Es laying above the grid ceiling. Id say its commercial? Office areas, with 600x600 drop in fittings. And a small workshop (no idea what they do, something with sewing machines!)

My manager is not the type of person i want to question, which is why im just getting ideas here, then maybe il confront him!

Il ask at college too!
thanks for your comments

 

[bugsy]

T & E ----ed over a suspended ceiling grid don't look good

 

[apprent10]

I know, its going to look shocking! Im glad its not my name going on any paperwork!!

So to answer my original question, is it against any regs to do it this way??

thanks.

 

[bugsy]

Well I'm sure if you paw through selection and erection, protection of cables, etc etc etc you will come to the conclusion ( the picture im painting of it anyway) is yes.)
You never know his term chuck em over the ceiling might mean cable tied to 50mm suspended tray

 

[apprent10]

Hi guys.

Well i decided to ask him today, as im always told that asking questions is a good thing!(?)

He made it very clear that just laying the cables on the grid is the idea, and that is the way it can be done. I asked what about the regs on containing them and he said theres no problem here.

I havn't got any books as yet, but i will be asking at college on friday.

Regards.

 

[uksel]

there's no problem as far as that's concerned. it's not pretty, but it's not wrong

the cable is adequately supported (by the false ceiling) and the unfortunate part of it is, they can throw JB's wherever they like as it's considered accessible for inspection and maintenance

 

[bugsy]

J.Bs what are they?

 

[baldsparkies]

Just take a peek above the suspended ceilings in many shops and offices, twin and earths sprawled everywhere in many cases.Its not nice and not ideal but then,welcome to the real world.

 

[apprent10]

J.Bs = Joint boxes.

Ok thanks for the other replys, i know many many others do it, so you think its all ok to do it like that, so long as the cables are protected from any sharpe edges there may be.


cheers

 

[bugsy]

The last op that used a srew terminal JB on a job of mine got his **** kicked for 5 mins , sat on the naughty step for a week on breaks and had to tear the pages out of his pocket mk catalouge!

 

[screech]

I only use JBs on a very last resort, if the cable cant be pulled back and replaced etc.

As for 'appret10' hi-jacking my thread ( lol)...You do see almost every place with false grid ceilings with justr cables thrown above them, i dont 'think' its against any rules as long as they are protected from sharpes etc.
Somebody correct me if im wrong though!

Though i would try my best to support them the best you can, like clip them up just off the grid, on the suspended wires? Or even clip along the perimeter walls where you can??

Mark.

 

[bugsy]

I only use JBs on a very last resort, if the cable cant be pulled back and replaced etc.

As for 'appret10' hi-jacking my thread ( lol)...You do see almost every place with false grid ceilings with justr cables thrown above them, i dont 'think' its against any rules as long as they are protected from sharpes etc.
Somebody correct me if im wrong though!

Though i would try my best to support them the best you can, like clip them up just off the grid, on the suspended wires? Or even clip along the perimeter walls where you can??

Mark.

There you go then , when you've popped a few ceiling tiles and a ton of cables come down on top you
you'll get the gist of what Im saying

 

[apprent10]

Sorry screech lol. Thanks for the reply tho

Bigsy... no sorry I don't get your gist...


Thanks

 

[SparkyJoe]

Its Just looks rough as a badgers ****.

You would think he would at least have used a spot of round band and took the weight off the ceiling / tidy it up a bit

 

[Darkwood]

You cannot run cables across the ceiling grids they must be adequately supported and not by laying them on the grid, ive only come across one type of cable allowed before which had been designed to withstand the sharp edges of the grid frame.

 

[bugsy]

You cannot run cables across the ceiling grids they must be adequately supported and not by laying them on the grid, ive only come across one type of cable allowed before which had been designed to withstand the sharp edges of the grid frame.

At last1

 

[Darkwood]

Reg 522.6.5, Reg 522.8.1 to name a few would give the impression that laying cables on grid ceilings isn't acceptable as the junction points of the grid are very sharp and can lead to damage of the cable during installation or maintenance whether it be you or another trade gaining access, a nicked cable could make the whole grid live!!! as earthing the grid isn't required and any light fittings have usually got an insulation layer of paint between their earth and the grid.
Its clear your on your learning curve and open to suggestion by your company but it beggars belief they are employing this practice or intend to, unfortunately it puts you in an awkward position.

 

[uksel]

not sure i'd say this instance was against the regs, i'd struggle to say your point was debatable at best

an example i can think of (which is probably higher risk) is when running cables in metallic trunking

any 90 degree bends or jumps are much more likely to suffer snagging or damage. especially when there's plenty of cables in there and you're trying to get the lid on, very easy for them to go pop when it's all juiced up

 

[Darkwood]

not sure i'd say this instance was against the regs, i'd struggle to say your point was debatable at best

an example i can think of (which is probably higher risk) is when running cables in metallic trunking

any 90 degree bends or jumps are much more likely to suffer snagging or damage. especially when there's plenty of cables in there and you're trying to get the lid on, very easy for them to go pop when it's all juiced up

With respect that would normally come down to installation and just been careful when laying them in, also the trunking should be earthed too so limiting the chance of sitting there live!!- waiting for the first unsuspecting person to touch it, and finally anyone else accessing the trunking should be at least knowledgable if not trained unlike the ceiling grid issue where multiple trades and other persons will remove tiles and may in turn snag and damage existing cables.
Overall at the end of the day the grid is open and exposed with sharp edges and accessable to anyone whereas the trunking would be a containment to enclose and protect the cables from damage, and if sharp edges are within the trunking then remove them or file them down.

Ive been fitting trunking for years, a good quality trunking should be used and any mitred bends you make should also be of a good standard, i find a metal brush wheel in my drill a god-send when de-burring and smoothing the edges.

Also remembering the spacing factor for trunking means getting lids on shouldnt be an issue, its sounds like your working with trunking filled beyond its capacity so you need to increase its size or fit additional.

 

[uksel]

yeah fair point.

the trunking being full isn't always the issue, it can be easy for a leg to be up and the clasp on the lid catch it. Plus sometimes, your not always the one who installed the trunking or ran the cables in.

like i say, i can see your point, but i dont think it is against the regs

 

[Darkwood]

yeah fair point.

the trunking being full isn't always the issue, it can be easy for a leg to be up and the clasp on the lid catch it. Plus sometimes, your not always the one who installed the trunking or ran the cables in.

like i say, i can see your point, but i dont think it is against the regs

Regs can be read in many ways but for the ceiling grid issue i still say it deffo a no no and its from experience i talk as local councils, clark of electrical works, building control etc in 3 different districts by me all express its against regs, as mentioned before i only was allowed to run a specially designed cable on the grid which looped in and out of some grid fittings with plug and socket assemblies, think they were thorlux and the flex had a toughened sheath which resisted the sharp edges of the grid.

 

[wattsup]

if its earthed, if its wired correctly no problem...if potato fields in lincolnshire were to become live because of your stupiditity then its your fault :

 

[uksel]

Regs can be read in many ways but for the ceiling grid issue i still say it deffo a no no and its from experience i talk as local councils, clark of electrical works, building control etc in 3 different districts by me all express its against regs, as mentioned before i only was allowed to run a specially designed cable on the grid which looped in and out of some grid fittings with plug and socket assemblies, think they were thorlux and the flex had a toughened sheath which resisted the sharp edges of the grid.

i take your point, and your examples are obviously more than valid. but this can just be down to company policy.

a good company will have the policy of 'full containment' and obviously running loose cables over suspended ceiling tiles would be a no-no for standard practice. but as a working example, the flex running from a klik multi-way box to each fitting above a suspended ceiling would immediately negate this being a requirement of the regs, which is really why i find it hard to accept this as a non-compliance.

and when it comes down to a court of law and compliance with legislation, could you get raped over it??

i wouldn't have thought so - then it could also be about how good your lawyer is

 

[Darkwood]

I think we all realise that these things never enter a court room but regarding flex cables - yes ive seen them laid across a few tiles but the same rules do apply and when your company starts working on local council buildings then all these bad practices could be costly as well as loosing future contracts as the clark of electrical will inspect and demand corrective actions, its also often seen that the flex enters the modular fittings 600/600 etc through a grommet then straight into the termination block - again this is a no no as the cable must be glanded or clamped to ensure any movement dosnt act directly on the connections.
I personally suspend the cables of any circuits neatly in all round band and flex to fittings likewise, this is acceptable and quick and easy compared to tray or trunking this way in future jobs it all can be wired and 'klicked' up ready for ceiling grid to be installed and just leaving the fittings to drop in and connect after.
Running cables across the grids is in itself poor workmanship and bad practice irrespective of any regs that may or may not cover this matter.
As mentioned already building control, clark of electrical works and the likewise wont allow this in any region i know of and just because your site may not be under such scrutiny dosn't make it any the more acceptable.

 

[uksel]

again agreeing with your last comment

but the OP is in a predicament over confronting his boss regarding compliance with the regs. regardless of bad worksmanship (which we all readily agree upon), he's asked advice, and i didnt think the advice of 'it's against the regs don't do it' was solid enough to encourage his actions.

it's a tough world out there and the OP isn't considered a competant person as of yet, he is basically labour

i think let it be said this is bad practice and condone those who disagree, but... don't put yourself out of a job where the case is arguable. if you're on your own do it right, if it's under his instruction it's his problem

don't go giving yourself a 1 way ticket to the dole office for an argument that might not hold water

 

[Darkwood]

again agreeing with your last comment

but the OP is in a predicament over confronting his boss regarding compliance with the regs. regardless of bad worksmanship (which we all readily agree upon), he's asked advice, and i didnt think the advice of 'it's against the regs don't do it' was solid enough to encourage his actions.

it's a tough world out there and the OP isn't considered a competant person as of yet, he is basically labour

i think let it be said this is bad practice and condone those who disagree, but... don't put yourself out of a job where the case is arguable. if you're on your own do it right, if it's under his instruction it's his problem

don't go giving yourself a 1 way ticket to the dole office for an argument that might not hold water

Agree with you on this also did get lost in the chit chat and digressed from the original post (as is easily done) but im sure it will give him food for thought.

 

[uksel]

he's probably cacking it now, won't know which way to turn

i think the best advise anyone can give in the current economin climate is

the guy you are working for doesn't seem to be all that, come here and ask any questions you like

but... keep your head down and get your papers, they'll earn you more between now and retirement than your hurt pride for doing a **** job cos 'he said so'

you did the right thing by coming here though, which suggests you are off to a good start