2330 assignment unit 3

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mrs electrician

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We have recently been given an assignment at college about a busy pedestrian precint,The shop has beenopen for 28 years and ha not been completley rewired since then, however circuits have been added. an assessment need to be taken pace to see if it should bepart rewired or fully rewired. protective devise is bs3036, cables are surface mounted etc.....

has anyone done this one?

please advise

 
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We have recently been given an assignment at college about a busy pedestrian precint,The shop has beenopen for 28 years and ha not been completley rewired since then, however circuits have been added. an assessment need to be taken pace to see if it should bepart rewired or fully rewired. protective devise is bs3036, cables are surface mounted etc.....has anyone done this one?

please advise
I added the additional circuits but didn't notify anyone, sorry. :|

 
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We have recently been given an assignment at college about a busy pedestrian precint,The shop has beenopen for 28 years and ha not been completley rewired since then, however circuits have been added. an assessment need to be taken pace to see if it should bepart rewired or fully rewired. protective devise is bs3036, cables are surface mounted etc.....has anyone done this one?

please advise
Hello Mrs Electrician! quick answer.. No!

But... just looking at it trying to guess what sort of thing they are maybe looking for?

{and trying to figure out what traps they are looking to see if you fall into?}

I guess the first thing they are looking at people to fall into is to say..

Oh! 17th.. must be RCD's & MCB's etc... and 28 years Must be rewired..

But:

3036 semi enclosed fuses are a perfectly acceptable method of providing overload protection.

Surface run cables do not need RCD protection!

A busy pedestrian precint... assuming this is a covered indoor environment...

sounds to me like there is unlikely to be any power supplied to use outdoors.. so No RCDs for external supplies!

As this is a business premises you would assume that any portable appliances used

are controlled under the jurisdiction of a supervisor / trained person ...

so no unskilled persons using sockets (H&S @ work?) therefore no RCD's required.

Overall loading on the installation for a shop... may be quite low,

compared to a domestic property?

e.g. NO major cooking / washing / showers or similar appliances..

No manufacturing machinery etc.. so cables.. assuming PVC T&E may still have some life left in them?

and remember some are LESS than 28 years old cuz some new circuits have been added! ;)

So assuming all the common tests prove safisfactory...

R1+R2,

Ins Res,

Polarity,

Max Zs,

general wear & tear of accessories / switches etc..

it may be ok without a re-wire? ?:| :|

dunno if this helps or not??

I may be barking completely up the wrong tree:p

in which case someone no doubt will call me a big wet blanket or similar! :^O :)

:)

 

mrs electrician

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Hey,

That has given me a totally different perspective.

I automatically presumed that it should be a rewire

some real good points there.

Thanks

 

thomo27

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maximum demand and diversity as additions may have been or most likely will have been added to the distribution board so very likely an upgrade to incoming supply could be required , if you want some advice on max demand and diversity just ask

 

paulh

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Just my tuppence worth but......... If it's a busy precinct shouldn't all the cables and accesories(skt outlets etc) be vandal proof, or at the very least wired in conduit. I know in schools the normal spacing for plastic conduit clips is too far apart so is quite often only 600mm between clips because of vandalism(or over exuberance to be politically correct)as an example.

looks like you have a lot to look over.

 
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consider also fuse ratings for circuits - ring or radials - mods maybe radial spurs from ring, will need checking to find out. Consider also testing to ascertain condition of cable, and Zs values. Also need to consider earth / main bonding arrangements. Can't think of anything else, hope that's helpful.

 

mrs electrician

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Something else i forgot to add was that it is 3 phase, 4 wire and a TNS system.

Aslo there are a number of trailing leads in use, which of course are easy to overload and surely not very good for bs3036 fuses as fusing factor is poor (am I correct in saying 2x the fuse rating. eg a 20a fuse will trip at 40a.)

Many thanks for everyones helpApplaud Smiley. It is really giving me something to think about.

it is quite strange because the majority of us at college are thinking straight away ofa full rewire, however after speaking to most electricians, most of them say only part rewire or a board change.

any other suggestions on wether it should be a full rewire or part are grateful as i have to write a whole assignment on this subject.

fun hey? :z

 
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