Please help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[mick78]

please help i have been given a piece of coursework to complete. it involves doing an electrical install on a 6 bed country house with 2 floors with a total floor space of 170 sq m on each floor.

i am completely new to this whole concept.
from what i have read so far i have to do this in stages like finding design current Ib etc.

do i have to use 2 ring mains for downstairs sockets because of floor space? as well as separate ring for kitchen.

do i have to do the same for lights?

i was trying to work out design current by adding up all loads eg, 2000W for hoover, 300W for television etc is this correct?

but have also found that ring circuits have to be 32A is this correct.?

do i apply diversity to the 32A or the summation of all loads?

lecturer has let slip that house is supplied single phase. if i have all these circuits can i get this single phase? ( is there a limit )

any help greatly appreciated.

 

[Engineer54]

First msge said total floor space 170sq m then msge 24? said firsst floor space 170sq m.

Think i'm confused as he is now!! lol!!

 

[telectrix]

just bung in 3 radials. be easier to extend when the floor area increases again.

 

[mick78]

sorry my mistake 170 sq m on each floor.

does that mean everything that has been posted is no use.

 

[goldie]

mmm yes my grammer aint 2 cracky on a sunday.... I was just pointing out that micks assignment originally said in question 1 that the house was total of 170sq m, then on question number 24 states that the 1st floor was 170 sqm. was working out the minimum ring main he can put on this but im thinking there are 2 different floor areas given here. Maybe i need early night??

Think i'm confused as he is now!! lol!!

 

[Octopus]

170 sq m on each floor.

any chance of the last 2 weeks in January at preferred rates of course!!!!!!!!!!!!!!!!!!!!

Understand the 170 sq m but not the next sentence!

 

[goldie]

nah, jst remember you can only have 1 ring main within 100sq metres though, u may need another circuit on the 1st floor.

sorry my mistake 170 sq m on each floor.

does that mean everything that has been posted is no use.

 

[goldie]

Understand the 170 sq m but not the next sentence!

Think he wants a holiday at engineer 54s holiday home like the rest of us pal

 

[Octopus]

Think he wants a holiday at your holiday home like the rest of us pal

And there was me thinking he's touting for business.

 

[ezzzekiel]

nah, jst remember you can only have 1 ring main within 100sq metres

not really can be as large as you want if its correctly designed

put radials upstairs to bedrooms,
downstairs ring
kitchen ring
shower
cooker
2 x lighting circuits

add up the mcb totals minus the largest circuit, take 40% of whats left + the largest you deducted at start (rule of thumb diversity figue) for your maximum demand.

keep the ammount of circuits down to a minimum to make life easier, prob want to see calculations for cable sizes and disconnection times etc..

 

[telectrix]

all down to loading, cable size, volt drop. if bedrooms are going to be used for making those "adult " movies, what with all those studio lights, might need to consider 4mm RFCs.

 

[mick78]

here is a copy of the drawing

 

[goldie]

Hope the assignment is going well mick, Dont forget to add these forum msgs to gain that distinction. lol

 

[mick78]

i will be lucky to get the magic 40%. if i then apply diversity i could end up with **** all.

 

[PC Electrics]

I've only skimmed through this thread, but what seems to stick out for me, is that the college, student and most posters only seem to consider the RFC as a suitable circuit type for suppying sockets. What about radials? There's a wide choice available: 32A/4mm, 25A/4mm, 25A/2.5mm and 20A/2.5mm. So plenty to choose from depending on loading and installation methods.

Our student also needs to ensure he fully understands the basic design requirements. The confusion over floor area should never have happened. in exam conditions this can be the difference between pass and failure.

And what about the college? They seem to be setting it's students exercises they simpy aren't ready for. How is that an effective means of education?

makes me worry for my apprentice.

 

[mick78]

i was focusing on RFCS as i thought they served the largest floor area, being 100 sq m.

from what i have read radials go to a maximum of 75 sq m.

again i am probably wrong.