Any thoughts on this....

[sythai]

Have a domestic customer that has part of a ring supplying a study area.

An he wants to have this extended in dado to include an additional 10-15 double sockets. To be used for computers, printers, mointers etc.

But he would like to be able to isolate these extra sockets at one point, a 'last man out switch' sort of thing.

Simples if this was a dedicated ring but it covers another room that will need to stay on.

Cant run any extra circuits/ legs in as he dosent want any floors up etc....

Only way I can think of doing this is by installing 2/3 x switched fused spurs each one supplying 5 x sockets ?

Or maybe is there a way I can make up some sort of contactor unit...?

Any thoughts please or better solutions ?

Many thanks,


Sy

 

[telectrix]

can you fit a single 16A MCB in a small enclosure so he can isolate the spur for the IT by flicking the MCB?

 

[sythai]

Not really.... he's quite specific on how it all looks so any enclosure etc would have to go below desk height and wouldn't be easy access then.

Supposse I could have a switch in the dado running to a small enclosure below with a contactor and 16a mcb in it...?

But then the question is how many sockets could I run off the 16a mcb..?

 

[Bigboy247]

Remember if its a lot ot IT equipement, high earth leakage. Play on that and try and get him to do the job properly and have a new circuit, or run round the outside of the building.

 

[pennywise]

How about a SWA sub main around the house to the office then MK Powerlink trunking then you could isolate the lot from the main incoming switch.

Powerlink Plus

 

[Deleted member 19807]

Have a look at www.mainlinepower.co.uk i saw this them at elex may or may not be any good for your situation

 

[Des 56]

Complete the ring main through the room by using the supply side of a 30 amp contactor
Then install 4mm off the load side to form a new radial around the computor room
Trigger the contactor by spuring off the load side for a switched fused spur to do that job
The load side of the fused spur to energise the coil

 

[sythai]

Thanks everyone for all your advice there.....

Have tried every option possible to run a new circuit in but customer just not happy with the idea.

But reckon this is the sort of thing I'm after....

Complete the ring main through the room by using the supply side of a 30 amp contactor
Then install 4mm off the load side to form a new radial around the computor room
Trigger the contactor by spuring off the load side for a switched fused spur to do that job
The load side of the fused spur to energise the coil

Another issue which I've just thought of is, I will be changing the MCB to an RCBO back at the board. And I'm not sure how this would act with a contactor further down the line. Is it likely to trip out....?

 

[sythai]

Thought as much.... after a bit of investigation looks like the RCBO will trip out everytime the coil is energised.

Oh well nearly there.

So would I be right then thinking I may be able to do it like this....

45a DP isolator, ring in and out on feed side, then off load side run a 4mm radial ?

Many Thanks,

Sy

(is there a way that if the customer really dosent want an RCBO, like in this instance with a lot of IT equipment that it can be left out with their consent and noted on the EIC, obviously if is it surface, or below 50mm deep etc. But in this instance where it is an existing circuit....? Really have my doubts)

 

[Guest123]

So would I be right then thinking I may be able to do it like this....

45a DP isolator, ring in and out on feed side, then off load side run a 4mm radial ?

You would then be spurring ALL the additional sockets from one point of the ring circuit thereby massively overloading the ring circuit at this one point....a big no no IMO.

 

[pennywise]

personally wouldn't give the customer the choice, new circuit end of, then start to plan routes which are unobtrusive around the house. Is the study on the ground floor

 

[sythai]

personally wouldn't give the customer the choice, new circuit end of, then start to plan routes which are unobtrusive around the house. Is the study on the ground floor

I'm also thinking the same now.... did like to see if other options were avalaible first though

Nop it's located across the other side of property in the 'west wing' on it's own mezzanie floor... (pretty posh place)

Oak floors throughout !! Will see what he reckons to a nice SWA round the outside, gotta pop back tomorrow anyway.

Cheers chaps

 

[pennywise]

Sounds like it's a Submain up in any cupboard you can find then take it across the loft then down to floor level in the study or out the con position with an SWA up the outside wall to the loft then across. Good luck with the convincing bit

 

[thewetspark]

A bit out of my experience or qualification but how about putting an MCB in the same box as the contactor to limit the total load on that "spur"?

 

[GTLElectrical]

Hi Si

Interstingly I have done a few installs using Mainline and work closely with the supplier ( Mainline Power )and think it would be perfect for your project as it has a 4mm CSA and therefore does not need to be ringed on a 32A breaker so you can just install it as a spur off the ring.
This is exactly what I did on a couple of occasions in schools for their computer service/test areas so that they could plug in whatever they wanted wherever they wanted to and they were extreamely happy. Infact I did exactly what is suggesting by running the ring to a DP45A isolator and running the mainline spur from that so that they had local isolation where they wanted it.
The nature of the product allows you to check the zs at any point on the circuit to make sure it is good which is very reassuring as you can check it is all good! As for the RCBO if you are using it for testing then it may or may not be a good idea depending on how competant your customer is, I would err on the side of putting one in to cover yourself and taking it out if it proves to be a problem but only on their request. Computers tend to have a high earth leakage current and are quite likely to trip an RCBO but I wouldn't stick my neck out and suggest that it not a good idea to have one.

Hope this helps

Greg