Joining two lengths of s.w.a Cable

[padsterlad]

hey there
at work we have jus got an new extraction system and to be able to get enough power to the control pannel and motor i had to cut the 35mm S.W.A cable that feeds the nearest distribution board in half,then connect them back together through large terminals.then adding another 16mm s.w.a cable to each phase in the terminals which obviously conects to its own separte box with an isolator and big enough MCB the extraction now works correctly!

My problem is i dont feel that the connections through the terminals is strong enough because 35mm s.w.a cable is tough stuff and the terminals look like they could pop off the din rail anytime!

i was wondering if there was a standard way of doing this which is safe and realiable??

Any help would be much appreciated

cheers Padsterlad!

 

[holmslaw]

..

 

[Spark123]

Normally we would run a supply from a distribution board to supply a piece of equipment as opposed to splicing into a distribution cable.

To make a decent connection in what you have we would use a something like 2 stud terminals and lugs for each of the lives in a relatively large enclosure.

 

[ColJack]

bloody cowboy..

if you want another board then you piggy back the smaller one off the tails in the old one, not cut into the cable and tee off it..

you could always use a cold pour splice joint like they use underground..

 

[ericmark]

I can't see what you describe complying with 433.2.2

Who do you work for only the DNO does that sort of job.

 

[ban-all-sheds]

i was wondering if there was a standard way of doing this which is safe and realiable??

Probably for the people you work for to employ an electrician who doesn't have to go to a DIY forum to ask how to do his job properly.

 

[padsterlad]

i am an apprentice electrical engineer! my mentor left my company half way through my apprenticeship i do still go to college 1 day a week as i still work 4 days a week and i have another 2 years left of a 5year apprenticehip ive just started my first year HNC!
The only reason i couldnt use an mcb in the distribution board is because the 32kw motor requires a larger type of mcb which is a 100amp type D and once you get larger than 63 amp three phase the terminals in the Mcb become further distanced apart which means it cant simply be slipped onto the forks of the distribution board (imagine fitting two wrong size jigsaw peices together :/ ) therefore i had to opt for another idea!

This is why i split the incoming cable and introduced another s.w.a. cable into the system running to its own separte isolator then to the new mcb then to the control pannel then to the motor which powers the fan.(The splitting and joining termination is in one enclosure and obviously the new isolator and mcb is in a smaller distribution board enclosure).

i had heard about joining them with resin which is used for underground but dont think this would look too good running half way up the wall.The connections are good and the extraction works perfectly so we could live with the work i have done.
But due to my lack of experience and because i want to better myself as an elctrical engineer i thought i would ask around and see if there where better ways,and here i can ask houndreds of people whereas asking 1 or 2 people wouldnt have the same effect lol

Sorry to the people i have offeneded, but is it such a crime to care?

Padsterlad

 

[maguire]

Sounds like the lad is doing a grand job under the circs and has enough balls to complete the job safely, if not technically brilliant and has shown enough inititive to get on with it and the sense to ask advice kinda like the young men we had in the air over the south coast 65 years ago and if you cannot offer help and advice without cynasism shut the **** up
Devlin

 

[ban-all-sheds]

Sorry to the people i have offeneded, but is it such a crime to care?

No - but it is almost certainly a crime for you to be doing the jobs you are doing, and for your employer to be asking you to do them.

Read the EAWR.

Then read my earlier post again and try this time to recognise that it says that your employer has not got the right person employed to do the jobs it needs doing. That is not your fault, nor have they got grounds for getting rid of you because their qualified electrician left.

But for them to ask you to fill his shoes, and for you to agree to work beyond your level of competence is irresponsible and dangerous. And asking how to do things on an Internet DIY advice forum, particularly after the event, is a very unsound strategy and could lead to something going seriously t**s-up for which you and your employer will end up in court.

 

[Spark123]

I'm assuming the load is three phase?
Why a 100A type D MCB? I can't imagine you ever getting Zs low enough unless it is almost on top of a sub station!
A 32Kw 3phase motor will only be pulling about 45A per phase FLC, will be going to shift a fair amount of air!

 

[padsterlad]

Right look i didnt come to this site to have some political debait about what i can and cant do at work.i think you need to take a step into the real world sunshine and realize

'try this time to recognise that it says that your employer has not got the right person employed to do the jobs it needs doing. That is not your fault, nor have they got grounds for getting rid of you because their qualified electrician left'
maybe they dont have the right person yet and maybe i did take a little bit longer to finish the job and maybe i did run into a few more problems but im an apprentice electrical engineer and what better way to learn than the hands on experiance(You cant learn to swim by being scared of drowning but u can use floats, you cant learn to ride a bike by being scared of falling off but you can use stableizers)i like to think of myself as quite a knowledgeable lad but is knowledge knowing how to do somthing or knowing how to ask something? i have done the job and its working fine.recognise its working fine.i do have to ask people what to do sometimes like people at college and other qualified electrical engineers and again your right they dont have the grounds to get rid of me because our qualified electrican has left but i was employyed to learn off him an eventually take over his job.due to unexpectted circumstanses he left ,leaving me to
a)find another job/apprenticeship
b)get nitty and gritty hands on and dirty and battle it out and finish the other half of my apprenticeship.

Maybe when you where a kid opportunities and jobs used to smack you in the face everyday,but these days times are hard and jobs dont come around so offten due to the current economical climate.

so in a nutshell how do you become compotent without doing somthing because that is what you have basically just said to me.
i have nvq level 2 and 3 ,i have btec c&g ONC 1st and 2nd and now im doing HNC 1st and 2nd.i also have my 17th edition and part p,and im due to start my PAT testing if that doesnt say im not competent i don't know what does.
ohh wait a minute yes thats right i don't know anything because i decided id try a diy forum for an answer.
Get real man!!!!!!

On the otherhand if anyone has any real solutions to my problem please feel free to comment
cheers Padsterlad [/quote]

 

[ban-all-sheds]

Right look i didnt come to this site to have some political debait about what i can and cant do at work.i think you need to take a step into the real world sunshine and realize

Tell it to the judge.

I wish you and your employer the best of luck, not that they deserve it.

Have they suddenly increased your salary to match your suddenly increased responsibilities?

I wonder if their insurers know about this?

 

[ColJack]

did you check what the fuses / breakers are for that 35mm feed?
are they safe for the 16mm that you've tacked on?

is it installed in such a way as to comply with the following?

433.1.1 The operating characteristics of a device protecting a conductor against overload shall satisfy the following conditions:

(i) The rated current or current setting of the protective device (In) is not less than the design current (Ib) of the circuit, and

(ii) the rated current or current setting of the protective device (In) does not exceed the lowest of the current carrying capacities (Iz) of any of the conductors of the circuit, and

(iii) the current (I2) causing effective operation of the protective device does not exceed 1.45 times the lowest of the current carrying capacities (Iz) of any of the conductors of the circuit.

specifically part (ii)? and also..

433.2.2 The device protecting a conductor against overload may be installed along the run of that conductor in the part of the run between the point where a change occurs ( in cross-sectional area, method of installation, type of cable or conductor, or in environmental conditions ) and the position of the protective device has neither branch circuits nor outlets for connection of current-using equipment and fulfills at least one of the following conditions:

(i) It is protected against fault current in accordance with the requirements stated in Section 434
(ii) It's length does not exceed 3 m, it is installed in such a manner as to reduce the risk of fault to a minimum, and it is installed in such a manner as to reduce to a minimum the risk of fire or danger to persons ( see also Regulation 434.2.1 )

??

you've already made a bad mistake since the 16mm SWA is not rated for 100A so the cable feeding the new board / breaker will melt before the breaker trips..

 

[Spark123]

i have nvq level 2 and 3 ,i have btec c&g ONC 1st and 2nd and now im doing HNC 1st and 2nd.i also have my 17th edition and part p,and im due to start my PAT testing if that doesnt say im not competent i don't know what does.

You may have sufficient qualifications however competence comes with experience.
To gain the necessary experience and knowledge you need to be under the supervision of someone with the necessary experience and knowledge, this is where your company is letting you down and breaking the law (Electricity at Work Regulations).

i have done the job and its working fine.recognise its working fine.

It may be working but is it safe? How do you know it is safe? It is a very dangerous assumption to make that as it is working it is safe, assumption being the mother of all [mistakes]

i do have to ask people what to do sometimes like people at college and other qualified electrical engineers and again your right they dont have the grounds to get rid of me because our qualified electrican has left but i was employyed to learn off him an eventually take over his job.due to unexpectted circumstanses he left ,leaving me to
a)find another job/apprenticeship
b)get nitty and gritty hands on and dirty and battle it out and finish the other half of my apprenticeship.

I can sympathise with what you are saying however it is the responsibility of your company to ensure yours and others safety, if this meant employing another fully qualified electrician then so be it.
It is very difficult to explain to someone exactly how a job has been done, without being there things can be skipped over which would be obvious had someone like myself seen the job.

ohh wait a minute yes thats right i don't know anything because i decided id try a diy forum for an answer.
Get real man!!!!!!

Reality of it is you cannot jump into anything with both feet, you need to learn and do everything properly which basically means you need to learn from a competent person, I'm envisaging you are only about 2 years into your apprenticeship? If so it is criminal to expect you to learn on your own.
From what I remember of ONC it is mainly theoretical stuff such as powerfactor, phasor diagrams etc but nothing on installation work, I don't even think they taught us how to wire a plug.

 

[jj4091]

I think what people are trying to say is that your enthusiasm & ambitons are to be applauded, but there is more than technical skills involved here that could well have serious repercussions for yourself & your employer & you should seek advice before you start not after the job is complete, it makes you look a bit silly if you have to rip it all out & start again. I get the impression that you are a concientious person trying to better yourself, but I do'nt think you will be able to live with your conscience if you kill somebody, if not with this job then maybe another, & I'm not sure it would be a legal defence. There must be some body that can advise on a better way for you to complete your apprenticeship & would suggest that it might be a good idea for you to seek that sort of advice aswell as the technical type. Also I am not sure how you will prove to have served a recognised apprenticeship in the future if you continue as you are. You may find this site helpful http://www.theiet.org/Forums/forum/index.cfm?nocookies=yes Good luck.