New CU and meter tails etc

[pc1966]

I'm not sure what you have read about the SPD, but they rarely cause trouble and these days most CU come with one as standard. Cost is modest, typically a few tens of pounds now, and compared to the whole CU change (or analysing risk for fitting or not) not worth omitting.

It is not always lightning spikes that can be a risk, it can be high current faults being disconnected.

For most of the time you ought not to need them as mains equipment is supposed to stand a few kV impulse voltage, but I would not put it past insurance companies to start weaselling out of claims if no SPD!

 

[Vortigern]

The idea that the solution to faults with RCBO be dealt with by replacing with MCBs is very poor to dangerous thinking/practice. Did he arrive on a horse by any chance?

If RCBOs start showing some faults as they are more sensitive then either we rectify the relevant wiring if feasible or he will take the RCBO out and fit the MCB.

 

[rajshar]

I'm not sure what you have read about the SPD, but they rarely cause trouble and these days most CU come with one as standard. Cost is modest, typically a few tens of pounds now, and compared to the whole CU change (or analysing risk for fitting or not) not worth omitting.

It is not always lightning spikes that can be a risk, it can be high current faults being disconnected.

For most of the time you ought not to need them as mains equipment is supposed to stand a few kV impulse voltage, but I would not put it past insurance companies to start weaselling out of claims if no SPD!

I agree with you that SPD gives an additional protection, but I am not convinced yet for their use in a home as a standard device yet. There is no case record to warrant SPDs at this time. As you said most of the mains equipment can handle some surges and the most sensitive equipment as computers etc, people do use surge protectors anyway. At least I do. The current faults can occur but I never experienced one . There could be scenarios, where SPDs are better suited.

 

[rajshar]

The idea that the solution to faults with RCBO be dealt with by replacing with MCBs is very poor to dangerous thinking/practice. Did he arrive on a horse by any chance?

You are right, it does create doubt in mind that's why I said that I am not satisfied by his response.

Right now as I have time, I'll surely take another opinion. I know everyone works differently and that's not a problem. It's just that I have taken two quotes and none of them mentions any testing prior to installation. I spoke with my colleague and even he said that pre install testing should be done because RCDs/MCBs are more sensitive and if there is any fault, they will become nightmare. Wired fuses are more forgiving but do increase the risk, so definitely need the upgrade. If no fault then perfect otherwise it will be an opportunity to put things right.

Btw which test is carried out to determine if bonding is required when there is no extraneous conductor.

I want to prepare myself with the right questions to ask this time.
Thanks

 

[rajshar]

Didn't see the edit option. Still learning about this forum.

 

[Midwest]

You are right, it does create doubt in mind that's why I said that I am not satisfied by his response.

Right now as I have time, I'll surely take another opinion. I know everyone works differently and that's not a problem. It's just that I have taken two quotes and none of them mentions any testing prior to installation. I spoke with my colleague and even he said that pre install testing should be done because RCDs/MCBs are more sensitive and if there is any fault, they will become nightmare. Wired fuses are more forgiving but do increase the risk, so definitely need the upgrade. If no fault then perfect otherwise it will be an opportunity to put things right.

Btw which test is carried out to determine if bonding is required when there is no extraneous conductor.

I want to prepare myself with the right questions to ask this time.
Thanks

Most CU changes don’t warrant an EICR beforehand. When I did CU replacements, I tested all the circuits before the old CU came off the wall. That was part of my pricing for the CU replacement.

IMO an EICR (before a CU change) is only necessary with a large property, or one where there is concern over of the condition of the installation. For example, I’ve had to replace the CU in my house, which is just over two years old. It would of been completely unnecessary to carry out a EICR beforehand, if I had been paying someone to do it.

 

[DPG]

The guy who told you he would take the RCBO out and replace it with an MCB if it kept tripping - you don't want him doing any electrical work in your house if that is his outlook on things.

Also, I would recommend having an SPD. Makes sense to have one now while the work is being done. Cost is minimal and it seems wise to be on the safe side. Never assume equipment is immune to surges and spikes. A company i know of once removed surge protection devices on some of its products, and guess what happened to the returns figures?

And it's not just lightning strikes that cause these spikes.

 

[nicebutdim]

Most CU changes don’t warrant an EICR beforehand. When I did CU replacements, I tested all the circuits before the old CU came off the wall. That was part of my pricing for the CU replacement.

IMO an EICR (before a CU change) is only necessary with a large property, or one where there is concern over of the condition of the installation. For example, I’ve had to replace the CU in my house, which is just over two years old. It would of been completely unnecessary to carry out a EICR beforehand, if I had been paying someone to do it.

If you were replacing a BS3036 board like that in the OP's images, rather than something of recent vintage, how might you approach the task?

 

[Midwest]

If you were replacing a BS3036 board like that in the OP's images, rather than something of recent vintage, how might you approach the task?

I would go to the house and have a look to the installation

 

[rajshar]

I found shortcomings from both electricians, so I am not going ahead with any one of them.

One was the attitude to replace RCBO with MCB if fault can't be rectified, instead he should have said that we must rectify the fault as that can be dangerous.

The second one is the earth bonding. When I told him that the supply pipes are plastic up to the house boundary he said he will leave the water pipe but he will upgrade the bonding to gas pipe anyway.

Strima said that you guys will calculate in this scenario if bonding is required. I read about bonding in the following article.

https://electrical.------.org/wiring-matters/years/2018/73-november-2018/myth-busters-2/

So it certainly makes a case to do proper assessment and calculation and then bond if required. So that is another thing

I will take few more quotes now because now I know what should I ask. I am fairly sure that old cables and sockets(MK brand) are in very good condition. The only sockets which I have doubt are relatively new ones fitted in the kitchen during kitchen refit about 9 years ago. They are of Lap. One was causing sparks during on/off and blew the fuse. I have changed 3 single Gang sockets with Schneider sockets. I will replace the other sockets in the kitchen too. Is Schneider fine or should I get the MK brand sockets.
May be I should just get an EICR first and if there is a need for rewire then sort that first at the first opportunity and then at the same time do the CU upgrade. If no faults then just do the CU upgrade. The new circuit in the kitchen can wait until that time.

Btw, a lot of you are emphasising on SPDs. I am still not convinced of their benefit in an average city house. Anyway if one has to go with SPD then is it allowed to mix different brands in a CU or not. I know you can't mix different brands RCD/RCBO/MCBs. Whatever make is the CU, it should be the same make components. So is it same for SPDs. I am asking this because there is huge difference on price of SPDs between different Makes?
Should I also go with AFDD as that provide additional protection too?
Thanks for all your help