Terminating SWA with Wylex REC Supply Isolators

[High Tower]

I thought 100A fused, are you sure. I thought this was what they were designed to do, or does the sub main cause the issue?

100% REC isolator is not fused!

 

[Michaelwgroves]

100% REC isolator is not fused!

Thanks, can bin this idea for sure.

 

[Michaelwgroves]

You do not want your calculations running to 100a per unit, drop your shower down to 8kw job and oven to 7kw etc etc. you need to be distributing 60a per unit with 200a per phase 3ph incomer.

if you exceed this the DNO will want you to sell your soul for the cost of the upgrade for your mains. People like tony and E54 will tell you of the frightening costs of big supplies.

It's not that a Ryefield is not ideal for the job it's the fact that you will need 12 sets of tails with 12 main switches all crammed into the trunking with 12 16mm SWA's. with a big DB like this then you still have the SWA glanded onto the trunking but the DB does the fusing, switching and doesn't need all of the tails. You can specify them with a lockable door too.

Btw once you apply cable calcs you may find that you may need 25mm SWA, and on 100a you would with out doubt need it.

I'll work on reducing load, but think 60A is going to be a struggle, 100A is everything on max at once, not made any allowances yet.

I think we're close the the optimum soloution, but to confirm; do you still think Ryefield is the correct soloution, or should I be looking at the Hager invictus TPN DB?

Thanks, really appreciate all the good advice.

 

[High Tower]

The hager DB is the cheapest solution by far and would greatly reduce install time, the Ryefield is expensive on the grounds it will also need a hell of a lot of tails and 12 x main switches.

Don't forget when working out max loads you need to apply diversity.

There is no way a bedsit would come even close to 60a let alone 100a, my 4 bed house hasn't ever tipped 50a

 

[Michaelwgroves]

I agree, it sounds mental. I have a family of 5 with loads of high power stuff and never tripped my 60A. I'll research Hager idea then post my loadings, see what you think.
If I can get down to 60A I can consider T&E again, could I put RCD in Hager?

 

[Octopus]

Sorry to say this matey, but with so many questions "up in the air", it does sound like you need the input of somebody with more experience, or you could find yourself in the poop big time.

 

[Michaelwgroves]

Sorry to say this matey, but with so many questions "up in the air", it does sound like you need the input of somebody with more experience, or you could find yourself in the poop big time.

Sparky got whisked away for surprise holiday, he'll have to have final sign off as its his name on the certificate, but want to get plan ready to discuss on his return as need to crack on.

 

[shocking_eg]

mate you shouldn't be doing this sort of work if you cant even tell the difference between an isolator and an over current protection device !

 

[Octopus]

Sparky got whisked away for surprise holiday, he'll have to have final sign off as its his name on the certificate, but want to get plan ready to discuss on his return as need to crack on.

Another ficticuous sparky !

 

[shocking_eg]

you will often find that the DNO company upgrading the supply will stipulate what they want fitted. many a times they request a ryefield board

 

[shocking_eg]

Sparky got whisked away for surprise holiday, he'll have to have final sign off as its his name on the certificate, but want to get plan ready to discuss on his return as need to crack on.

his name on test cert your name on design and install ! LOL

 

[High Tower]

I agree, it sounds mental. I have a family of 5 with loads of high power stuff and never tripped my 60A. I'll research Hager idea then post my loadings, see what you think.
If I can get down to 60A I can consider T&E again, could I put RCD in Hager?

No, T&E submains in flats isnt a good idea, because you then have the issue of discrimination between the sub RCD and the RCD's in the CU. I stand by the 250a DB and SWA being the most cost effective method.

I Echo what Murdoch says, i dont mind helping and giving advice so you know the best course of action to take, a informed customer is never a bad thing. The works proposed isnt particularly difficult and it certainly isnt rocket science, however, it is extremely difficult to do it well!!. and if you do make a cock of it then the kind of total load were talking about normally equates to a big fire.

To summarise: Cut out - Hager 250a DB- 63a sp mcb type c- 6" galv trunking- SWA .........Simples

 

[Michaelwgroves]

Just had a look at Hager, looks good and probably not much more than original idea. But I don't understand how it works. Plan is to use it as sub main. So main intake to 12 meters, then out of each meter into sub main before going off to each CU.
Hager looks like single 250A in then 12 60A out.
What am I missing ?

 

[Octopus]

and to look at some of your earlier threads I would say that you have too much focus on keeping the cost down and not on installing the correct solution.

 

[Michaelwgroves]

Another ficticuous sparky !

I've tried to ignore your constant nit picking which adds no value to this thread, but your last comment is too much. If you care to research compulsory HMO licensing you will discover it is impossible to get a licence without a certificate.

If you have anything to add to this thread of value please do so, but otherwise please keep your negativity to yourself.

 

[High Tower]

I dont remember meters being mentioned, How are you intending on doing this?, it opens a whole can of worms now. are you having your own meters installed and charging your tenants yourself or are you intending on having prepay meters, if its pre pay then the DNN must install them and their own Ryefield to supply them, and that will be big cost!.

If you are having meters in the switch room then you are back to Ryefield - meter - switch fuse - galv - swa and with all of that you will need a switch room the size of a bedsit for all of that 12 x over

if you are having the meters in the bedsits then the hager solution will work. you can get cu's to go in the bedsits that have meters built into them, so it would be
Cutout - hager - swa - cu with integral meter.

 

[Octopus]

I dont remember meters being mentioned, How are you intending on doing this?, it opens a whole can of worms now. are you having your own meters installed and charging your tenants yourself or are you intending on having prepay meters, if its pre pay then the DNN must install them and their own Ryefield to supply them, and that will be big cost!.

If you are having meters in the switch room then you are back to Ryefield - meter - switch fuse - galv - swa and with all of that you will need a switch room the size of a bedsit for all of that 12 x over

if you are having the meters in the bedsits then the hager solution will work. you can get cu's to go in the bedsits that have meters built into them, so it would be
Cutout - hager - swa - cu with integral meter.

Brilliant. People think sparking is so, so easy! This is one enormous can of worms

 

[Michaelwgroves]

his name on test cert your name on design and install ! LOL

No, his name on install, he's got to have the final word. But I will have a big input as you can see. Just to confirm I am not using a one man band but a large company based in Kent with several engineers.
Anyone that has worked with the council knows there is no cutting corners.

 

[Octopus]

I've tried to ignore your constant nit picking which adds no value to this thread, but your last comment is too much. If you care to research compulsory HMO licensing you will discover it is impossible to get a licence without a certificate.

If you have anything to add to this thread of value please do so, but otherwise please keep your negativity to yourself.

Its all very well doing research but you've said your sparky (if he exists) is on holiday. Leave it to the sparky to quote you for a price and then if you're not happy get a couple more in to quote.

If you are not happy with the imput from the members here maybe you should try other forums.

 

[High Tower]

Brilliant. People think sparking is so, so easy! This is one enormous can of worms

Like i say i dont mind helping with selection of the appropriate equipment best for the application. at the end of the day thats what were here for!, but i stand by my opinion that it would take a half decent spark to make a decent job of it!