level 3 2365 hotel

[Sam1989]

hi there this question is in regards to wiring the hotel on the 2365 design project. my question is can i just complete the installation with 4mm all round. the circuits consist of numerous radial circuits and a number of SFCU points for head towel rail and A/C unit. thanks

 

[Lister1987]

@Sam1989 - If you're on a training course, apply to join the trainees section of the forum, it has others that are studying and a wealth of information (and good knowledgeable mentors; Mine's a pint of bitter lads!).

You can also get help with some aspects of your learning BUT don't expect them to do your work for you, you'll at least need to have a good crack at it first and, where applicable, explain your reasoning.

Drop @Dan @Lou or any of the site team a message with your course information and they'll sort you out.

I'm trying to add new material in there too when I can find good stuff.
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hi there this question is in regards to wiring the hotel on the 2365 design project. my question is can i just complete the installation with 4mm all round. the circuits consist of numerous radial circuits and a number of SFCU points for head towel rail and A/C unit. thanks

What's your reasoning for using 4mm throughout?

 

[Sam1989]

@Sam1989 - If you're on a training course, apply to join the trainees section of the forum, it has others that are studying and a wealth of information (and good knowledgeable mentors; Mine's a pint of bitter lads!).

You can also get help with some aspects of your learning BUT don't expect them to do your work for you, you'll at least need to have a good crack at it first and, where applicable, explain your reasoning.

Drop @Dan @Lou or any of the site team a message with your course information and they'll sort you out.

I'm trying to add new material in there too when I can find good stuff.
[automerge]1577668565[/automerge]


What's your reasoning for using 4mm throughout?

ok so i was initially going to do 2.5 radial for sockets on a 20A breaker however the tutor introduced a radial circuit wired in 4mm with a 32A breaker. I then saw no reason why i couldn't just use 4mm all round for the sockets and heated towel rail and A/C unit, heated towel rail and A/C unit on a 16A breaker. He helped us do one of the circuits in the servery for the fridges and that was wired in 4mm on a 16a breaker. I know i can wire in 2.5 taking into consideration length VD etc but is there any reason why i can use 4mm. i have done all my cable calcs on a spreadsheet with 4mm. i was going to wait till i go back in to class after the new year to let my tutor correct it however if i could nail it 1st time round it would be easier. the only reason i can see him not allowing it is because its not practical with regards to the cost of material.

 

[Gawain]

What's wrong with a 2.5mm ring in the hotel rooms?
I'd certainly not want to run 4mm to sockets unless I really had to, there a pain to terminate in the back of a dsso, let alone a fcu.

 

[Strima]

I'd be putting 2.5 radials in from a 16 amp MCB purely because it's a hotel room so no high demand expected.

Has your tutor mentioned division of circuits to reduce disruption under fault conditions?

 

[Gawain]

I thought about rads, then decided rather than running a couple of rads, I'd do just the one ring to everything bar supply for heating.
Once you start talking about kettle, TV, towel rail plus charging technology, it'd very quickly add up to 16a plus if everything was on at once.

 

[Sam1989]

the tutor said no RFC radials only and then mentioned about the 4mm radial on sockets.
each room will have its own DB. the db will supply 4mm 32a radial for sockets. and i have now decided to go with 2.5 to SFCU connected to Towel Rad and then another 2.5 to a second SFCU for the air con unit.

as long as i have selected the correct factors and other calculations, this table should be correct,

 

[Gawain]

Why are you working out the hotel like that? Unless you have a different paper to me it doesn't ask for all that!
Plus why has your tutor said no rings?
It's your design to do as you please.

 

[Vortigern]

Well you wont be using just 60898 as you will need RCD for a lot of that circuit(s) Why 90 degree singles without using equipment rated to 90 degrees. You may well also need a type C 60898 for the air conditioning. Or RCD appropriately rated the same. But sure you can use 4mm on 32a but the rating may drop to a point where passing through insulation that you cannot use it. And of course it depends how big the hotel is and the length of the run. Hot in that Hotel with temperature of 40 degrees expected during operation of a kettle?

 

[Gawain]

Haven't got my project to hand, but iirc the singles is what has been decided for us.
We have a long list of what's being used where, it's installation methods and what we must include.
We also have a list of temperatures though out the install but we are told to ignore them for wiring purposes.

 

[Sam1989]

some of the information is a little extra just for me to get used to doing cable calcs etc. we are to be wiring in singles. the length of run is in the table and is in meters. i don't think i will need to put the A/C unit on C type. i may use a RCBO it is after all going to be wired with the use of SFCU. can i get a bit more information with regard to correct selection of protective device.

 

[KennyKen]

Remind me what the SFCU acronym is? Been out of the UK a longtime.

 

[Gawain]

Switched fused connection unit

 

[KennyKen]

Switched fused connection unit

SPUR ok.. Geez those acronyms are starting to sound Americanised

 

[Gawain]

Not a spur, as you can have a spur without a fcu.
Mostly fcu are used to de-rate off a ring/rad for example an extractor fan in the kitchen which only requires a 3amp supply, or for a local isolation to a built-in appliance.

 

[KennyKen]

Yeah I know..

We used to call them Fused Spurs

Switched or Non switched. With or without Neons.

 

[davesparks]

SPUR ok.. Geez those acronyms are starting to sound Americanised

No its not a spur, a spur is an unfused connection to a circuit.

 

[Sam1989]

Ok so the existing protective device I have chosen B 60898 16A with a 13A SFCU (switched fused connection unit aka switched spur aka plastic on the wall with neon in it or however you want to refer to it) would that be sufficient. The details off power and length of run are all in the table. Do really need to use a RCBO ?

 

[davesparks]

Ok so the existing protective device I have chosen B 60898 16A with a 13A SFCU (switched fused connection unit aka switched spur aka plastic on the wall with neon in it or however you want to refer to it) would that be sufficient. The details off power and length of run are all in the table. Do really need to use a RCBO ?

What is the SFCU for? The 16A MCB will almost certainly operate before the 13A fuse so really all it does is add an extra point of failure.

 

[Sam1989]

SFCU is purely part of design. The idea was introduced to us in class. If maintenance work needed to be carried out on either air con unit or heated towel rad. The work could be carried out with out needing to access the DB