New CU and meter tails etc

[rajshar]

Hi
I don't know if I should ask it here or the main electricians forum. It's about CU change and the work around it and the CU change will be done by a proper registered electrician.

I will try to upload the pictures so you can see what I am talking about. I took two quotations. One just ask for pictures and quoted me for new BG CU with RCBOs, meter tails, upgrade the earth cable as the old one is only 6mm.

The second one visited my house today and after looking at the meter fuse board gave me two quotes, one including materials and one just his labour, testing and certificate charges. He said there is no need to tell Building control as he is registered and his certificate covered it. His quote includes fitting new CU and meter tails. But he said he won't change the earth cable as that is coming out of cut out and he isn't allowed to touch that. He also told me that the tails from the cutout to the meter and then to the fuse board are 16mm. The cutout fuse is rated 100A. The length of tails from cutout to meter is about 60cm and from meter to the fuse board is about 120cm including all the bends. Is all this acceptable? I know that I can ask him to fit 25mm tails to the CU but who is responsible to change the tails from cutout to the meter and who is supposed to change the earth cable for bonding from cut out to the gas pipe.

I have an appointment scheduled with British Gas to fit an isolator between the meter and fuse board as the first electrician asked for it. Can British Gas electrician change the tails and earth bonding cable from cutout while fitting the isolator?
Sorry for a long description and questions.
Thanks

 

[rajshar]

It doesn't necessarily need to follow the same route, or end up at the same place inside. I obviously don't know the specifics of your house, but there's often an alternative route.

I know the route. It's straight from the water meter through my drive then under the hallway and into the kitchen. I had seen this pipe when drive was done and I saw it again when kitchen floor was tiled. We had to replace few damaged joists that time. That's why I said no builder pointed this to me that this lead pipe should be changed. We had this opportunity twice and wasted those opportunities. Just got more info from Thames Water and it seems the risk is very very low and it can be reduced further by taking few steps.

Water quality | Help | Thames Water

Learn more about water quality in your area, including what to do if your water looks or smells different to normal.

www.thameswater.co.uk

Now I won't be digging up to replace this. It may be easier to dig up the drive but can't do the kitchen.
Thanks.

 

[rajshar]

Makes sense to remove the lead pipe due to the obvious health risks it poses.

Having said that my Nan's house had lead piping all the way up the drive, through the yard and throughout the house and she lived to be 100.

Thames water is saying that because of limescale build up inside the pipe there is very little chance of lead leaching in to the water. They also add phosphate which acts as a limescale too to prevent any leaching of lead. I have been living in this house for 15+ years and so far no new health issues.
Thanks

 

[DPG]

Thames water is saying that because of limescale build up inside the pipe there is very little chance of lead leaching in to the water. They also add phosphate which acts as a limescale too to prevent any leaching of lead. I have been living in this house for 15+ years and so far no new health issues.
Thanks

Fair enough. I personally would have removed the lead pipe, same as I would fit an SPD if I was fitting a new consumer unit. But it's the individual's choice.

 

[rajshar]

My wife has been insisting to get out of Croydon for some time and now I think there is a good reason to move away.

I wish there was an idiots guide to buy house with all these important points. Anyway got good pointers here for my next house.
Make sure the electricity wiring is up to standard and no DIY surprises. If not bring it up to the standard before move in.
Check and if needed, replace anything under floor including water pipe because it is much more expensive once you start living.

 

[DPG]

My wife has been insisting to get out of Croydon for some time and now I think there is a good reason to move away.

I wish there was an idiots guide to buy house with all these important points. Anyway got good pointers here for my next house.
Make sure the electricity wiring is up to standard and no DIY surprises. If not bring it up to the standard before move in.
Check and if needed, replace anything under floor including water pipe because it is much more expensive once you start living.

It's also easy to worry too much sometimes though.

It's good that you look into things. A lot of people take absolutely no interest in their electrical system.

 

[pc1966]

I really don't get that why SPDs weren't made compulsory? Why majority of consumer boards being sold, don't have one?

To all intents and purposes they now are, the TL;DR version of the 18th edition regulation 443.4 is they shall be fitted in many cases (risk to life, business interruption, impacts many people), and in all other cases a risk assessment shall be performed. It then goes on to detail the risk assessment process 443.5 based on lightning flash density in the region, style of distribution network, etc.

The get-out is the bit where it says "except for a single dwelling unit where the total value of the installation and equipment therein doe not justify such protection".

So if you don't value your stuff and go with the cheapest bid, guess what happens?

The other point is about type A and AC RCD)RCBOs. There is no difference in price and type A offers better protection as it can deal with residual DC and still a lot of sellers are selling pre populated CU with type AC RCD/RCBOs. I even heard that a few European countries actually have banned type AC RCD/RCBOs.

It is looking like the 2nd amendment to the 18th regulations will also greatly reduce the allowable range of applications of type AC RCD in the UK as well.

I guess the main reason they are still sold is they have been fractionally cheaper to make in legacy designs and/or a lot of back stock to get rid off. Certainly I would always go with type A as the minimum specification for anything now, as they are available from most suppliers and the new compact RCBO generally are all type A.

 

[Babs]

Thanks Strima, telectrix and westward10.
I thought the earth cable from cutout with the tag "Do not remove" is the main earth and it is going in to the fuse board, routed behind the ply board. My understanding is that my electrician should upgrade the tails to 25mm from the meter to CU, regardless what is from the cut out. He should also be able to upgrade the earth bonding from the CU to gas/water pipe provided I still need it as the street pipes are plastic.

What can I ask the suppliers electrician other than his usual work of fitting an isolator. Obviously he is going to take the fuse out for a safe work environment. If I supply him the tails and earth cable, can he change them. Obviously a lot will depend on his mood and schedule.
Here is the pic as requested.

Rajshar,
I don't think you understand the knowledge you are portraying. What size is your cut-out fuse? What's the maximum ampage 16mm and 25mm cables can safely carry? If the DNO have attached 16mm to your cut-out why do you want to replace them with 25mm?
Why can't the quoted electricians fit an isolator, that's the simplest job of the lot. A qualified leccy would 100% definitely not allow a customer to purchase the tails and isolator. Too much knowledge is a dangerous thing.

 

[rajshar]

My wife has been insisting to get out of Croydon for some time and now I think there is a good reason to move away.

I wish there was an idiots guide to buy house with all these important points. Anyway got good pointers here for my next house.
Make sure the electricity wiring is up to standard and no DIY surprises. If not bring it up to the standard before move in.
Check and if needed, replace anything under floor including water pipe because it is much more expensive once you start living.
This

To all intents and purposes they now are, the TL;DR version of the 18th edition regulation 443.4 is they shall be fitted in many cases (risk to life, business interruption, impacts many people), and in all other cases a risk assessment shall be performed. It then goes on to detail the risk assessment process 443.5 based on lightning flash density in the region, style of distribution network, etc.

The get-out is the bit where it says "except for a single dwelling unit where the total value of the installation and equipment therein doe not justify such protection".

So if you don't value your stuff and go with the cheapest bid, guess what happens?


It is looking like the 2nd amendment to the 18th regulations will also greatly reduce the allowable range of applications of type AC RCD in the UK as well.

I guess the main reason they are still sold is they have been fractionally cheaper to make in legacy designs and/or a lot of back stock to get rid off. Certainly I would always go with type A as the minimum specification for anything now, as they are available from most suppliers and the new compact RCBO generally are all type A.

I read in one of the threads that risk assessment has been made so difficult that it is easier to fit one than going through all the hassles. That doesn't prove it is necessary to fit one. If they really save life and damage to products then just like RCD they should have been made compulsory rather than leaving grey lines. What I have read and concluded is that there are areas which will definitely benefit from having one and there are areas where they aren't necessarily. My area isn't prone to lightning and the supply cable is undergoing.

Despite my reservations, I looked at a Fusebox CU with pre fitted SPD and its price is not much more than a standard BG consumer unit and almost half the price than wylex or Hager. So if Fusebox is good I may go with this one

F2014MX 14WAY T2 SPD FUSEBOX - FuseBox

F2014MX 14WAY T2 SPD FUSEBOX DESIGN FEATURES BS EN 61439-3 IP20XC 1mm ELECTRO GALVANISED STEEL (ZINC) RAL9001 SMOOTH POWDER COATED FINISH T2 SURGE PROTECTION TAIL CLAMP (ACCF) EARTH AND NEUTRAL TERMINAL BARS AT THE TOP REMOVEABLE AND RAISED DIN RAIL ROUND EASY TO REMOVE KNOCKOUTS EXTRA HEIGHT...

cpelectric.co.uk

Just need to understand the difference between the all integrated double module Wylex SPD and the Fusebox single module SPD with a MCB.
Thanks

 

[Strima]

Just need to understand the difference between the all integrated double module Wylex SPD and the Fusebox single module SPD with a MCB.

Some manufacturers specify a certain protective device size for their SPDs and use an MCB within the board, others are happy for the suppliers fuse, normally up to 100 amps, to provide overcurrent protection for their SPDs. You need to dig into the manufacturers instructions.

For example Wylex are happy with <=125 amp protection:

SPDs are not just about lightning strikes, they also protect against heavy surges put on the network by things such as heavy industrial switching for example.

 

[rajshar]

Some manufacturers specify a certain protective device size for their SPDs and use an MCB within the board, others are happy for the suppliers fuse, normally up to 100 amps, to provide overcurrent protection for their SPDs. You need to dig into the manufacturers instructions.

For example Wylex are happy with <=125 amp protection:

View attachment 65515

SPDs are not just about lightning strikes, they also protect against heavy surges put on the network by things such as heavy industrial switching for example.

Thanks for clarification Strima.

 

[rajshar]

Rajshar,
I don't think you understand the knowledge you are portraying. What size is your cut-out fuse? What's the maximum ampage 16mm and 25mm cables can safely carry? If the DNO have attached 16mm to your cut-out why do you want to replace them with 25mm?
Why can't the quoted electricians fit an isolator, that's the simplest job of the lot. A qualified leccy would 100% definitely not allow a customer to purchase the tails and isolator. Too much knowledge is a dangerous thing.

I think you have misunderstood me. It's true I don't have the knowledge at par with you guys nor I am trying to be an electrician, I am just trying to understand the general bits. If I had no knowledge and I didn't ask here then I would have gone ahead with one of those two electricians, who would have done a shoddy job.

The isolator is being fitted by British gas, the electricity supplier. My electrician will work from isolator. Some of you guys said that they will install 25mm tails and 16mm earth but that will be from isolator. So I asked the question that can I ask the British Gas electrician to fit 25mm tails up to isolator and if required I can provide him the tails. This is the reason I ask the question as I don't know that he will do this or not.
If fuse is 100amp in the cutout then he should fit the rated cables anyway. If fuse isn't 100amp then we will have to ask the DNO to upgrade the fuse and they will only upgrade the fuse if the rated cables are already there. My understanding is that DNO won't touch the tails as it isn't their responsibility.

 

[Babs]

I think you have misunderstood me. It's true I don't have the knowledge at par with you guys nor I am trying to be an electrician, I am just trying to understand the general bits. If I had no knowledge and I didn't ask here then I would have gone ahead with one of those two electricians, who would have done a shoddy job.

The isolator is being fitted by British gas, the electricity supplier. My electrician will work from isolator. Some of you guys said that they will install 25mm tails and 16mm earth but that will be from isolator. So I asked the question that can I ask the British Gas electrician to fit 25mm tails up to isolator and if required I can provide him the tails. This is the reason I ask the question as I don't know that he will do this or not.
If fuse is 100amp in the cutout then he should fit the rated cables anyway. If fuse isn't 100amp then we will have to ask the DNO to upgrade the fuse and they will only upgrade the fuse if the rated cables are already there. My understanding is that DNO won't touch the tails as it isn't their responsibility.

I think you have misunderstood me. It's true I don't have the knowledge at par with you guys nor I am trying to be an electrician, I am just trying to understand the general bits. If I had no knowledge and I didn't ask here then I would have gone ahead with one of those two electricians, who would have done a shoddy job.

The isolator is being fitted by British gas, the electricity supplier. My electrician will work from isolator. Some of you guys said that they will install 25mm tails and 16mm earth but that will be from isolator. So I asked the question that can I ask the British Gas electrician to fit 25mm tails up to isolator and if required I can provide him the tails. This is the reason I ask the question as I don't know that he will do this or not.
If fuse is 100amp in the cutout then he should fit the rated cables anyway. If fuse isn't 100amp then we will have to ask the DNO to upgrade the fuse and they will only upgrade the fuse if the rated cables are already there. My understanding is that DNO won't touch the tails as it isn't their responsibility.

Rajshar,
Your comments strengthen my belief that you are out of your depth with your questions to "experts" for want of a better word. You keep mentioning the 100 amp cut-out and asking the DNO to upgrade it to 100 amp. You obviously don't realise that almost every family dwelling will operate on a 60 amp fuse, 80 amps in extreme cases. To satisfy yourself, go around your house at any time and see what is switched on and approx how much ampage is being used. I'll bet you never get to more than 30.

 

[rajshar]

Rajshar,
Your comments strengthen my belief that you are out of your depth with your questions to "experts" for want of a better word. You keep mentioning the 100 amp cut-out and asking the DNO to upgrade it to 100 amp. You obviously don't realise that almost every family dwelling will operate on a 60 amp fuse, 80 amps in extreme cases. To satisfy yourself, go around your house at any time and see what is switched on and approx how much ampage is being used. I'll bet you never get to more than 30.

You can think of what you want to think. It may be that 60 or 80amp is enough at this time. There is something called future proof. How about tomorrow we want an EV point?
DNO has no problem to upgrade the fuse if rated cables are there. I as a customer don't want to pay again for 25mm tails if it can be installed now.
Now having knowledge or asking questions, I don't think there is anything wrong asking. You can ignore this thread if you think I am wrong.

 

[Babs]

You can think of what you want to think. It may be that 60 or 80amp is enough at this time. There is something called future proof. How about tomorrow we want an EV point?
DNO has no problem to upgrade the fuse if rated cables are there. I as a customer don't want to pay again for 25mm tails if it can be installed now.
Now having knowledge or asking questions, I don't think there is anything wrong asking. You can ignore this thread if you think I am wrong.

It's all to do with diversity. Presumably you understand what diversity is regarding electricity.

 

[rajshar]

I do understand diversity and I know we don't use all the appliances and other stuff at the same time. Just like so many others, we do have plans for Electric Vehicle.

I think this post is becoming unnecessary lengthy. The original question has been answered and now I know how to proceed with my next quote and what questions to ask.

Thanks to everyone who contributed positively and suggested what should be done.
Thanks