Shower pull cord blowing fuse in consumer unit - pics

[JohnD]

the cable shows signs of charring, so is damaged at least in places, most likely it is undersized for the load you want to put through it so needs replacing entirely.

So yes, new switch, new cable, new MCB (preferably RCBO) and new CU.

Because a CU is mostly just a metal box full of air, a big empty one is not much more expensive than a small empty one.

To my eye, the cables in fuses 4 and 1 also look suspiciously dark, so perhaps they have also overheated and need replacing. Once the copper wire has overheated, it softens, and will not make a reliable connection again, so will overheat and loosen and overheat even more.

 

[MattB83]

the cable shows signs of charring, so is damaged at least in places, most likely it is undersized for the load you want to put through it so needs replacing entirely.

So yes, new switch, new cable, new MCB (preferably RCBO) and new CU.

Because a CU is mostly just a metal box full of air, a big empty one is not much more expensive than a small empty one.

To my eye, the cables in fuses 4 and 1 also look suspiciously dark, so perhaps they have also overheated and need replacing. Once the copper wire has overheated, it softens, and will not make a reliable connection again, so will overheat and loosen and overheat even more.

Out of interest do you know what a ballpark figure for a total rewire is likely to be? Small 3 bed house on 2 floors if that's of any use. Feel like I couldn't cope with the upheaval at the moment with a small child and nowhere else to stay while it was being done though!

 

[MattB83]

The No.3 fuse shows signs of overheating on the outside of the case, and the cable from it appears to be burnt.
New consumer unit time.

I think this is down to the fuse wire that was wrapped around the terminals of the fuse - so when it's blown, rather than be contained in the housing it's heated up the outside of the case.

 

[oldbutnotdead]

I think this is down to the fuse wire that was wrapped around the terminals of the fuse - so when it's blown, rather than be contained in the housing it's heated up the outside of the case.

Can't actually see the pic...if the insert that the fuse carrier was sat in had flash burns on it then your hypothesis has merit. But your theory doesn't explain why the cable connected to that insert is burnt.
Your house, your decision- not sure how much a 40A breaker (or fuse) and mounting will cost for that unit but as a short term fix upgrading that OPD is a must (unless you can do without the shower).
As for the rest, get some local electricians in to assess and price. You're not necessarily looking at a full rewire, depends on many things.

 

[Taylortwocities]

Out of interest do you know what a ballpark figure for a total rewire is likely to be? Small 3 bed house on 2 floors if that's of any use. Feel like I couldn't cope with the upheaval at the moment with a small child and nowhere else to stay while it was being done though!

No way of telling without a site survey. Not cheap, if you will be living there, the house is full of furniture and you will want power on at the same time!
Find a couple of REGISTERED electricians and ask for a quote.

 

[SUNRAY]

This has been in place for at least 40 years and still passes all annual tests
View attachment 201220

And from last night:

If I recall rorrectly these only ever had main switch ratings of 40 or 60A and RCD of 25 or 63A.
I'm confused, I have worked on 3ph versions of these boards and OP's RCD looks more like 4 pole size, however I can see the 63/2 marking.
A 63/2 [manufactured nov 1992] removed from a 6 way fairly recently with a fuse for size comparison:

A 6 way from an old thread:

And my shed with one of each OCD, this was a second hand unit fitted about 1994:

 

[MattB83]

No way of telling without a site survey. Not cheap, if you will be living there, the house is full of furniture and you will want power on at the same time!
Find a couple of REGISTERED electricians and ask for a quote.

Thank you - I'm going to arrange for an electrician (that came recommended from a plumber who I trust) to talk through our options.

I'm not resistant to having the necessary work done at all, although after some bad decisions regarding tradespeople I am now very wary of who we trust with our safety and our monty - my wife from the North-West on the other hand 'So it's been like this for 15 years, it works fine and it's just become dangerous today?' is an example of what I will need to contend with...

 

[SUNRAY]

Thank you - I'm going to arrange for an electrician (that came recommended from a plumber who I trust) to talk through our options.

I'm not resistant to having the necessary work done at all, although after some bad decisions regarding tradespeople I am now very wary of who we trust with our safety and our monty - my wife from the North-West on the other hand 'So it's been like this for 15 years, it works fine and it's just become dangerous today?' is an example of what I will need to contend with...

I found a way round that with my ex, the smell of shi... sewage soon convinced her the kitchen floor needed to be dug up... oh and while we're at it we'll fix this serious damp problem.

Oh and now you want a new kitchen? What's wrong with the old units darling, they can go straight back in place??

Just show her the melting wires.

 

[flameport]

not sure how much a 40A breaker (or fuse) and mounting will cost for that unit

40A devices haven't been made for years so fitting one of those isn't an option.
Very unlikely that fusebox is suitable for devices over 30A anyway.

 

[SUNRAY]

40A devices haven't been made for years so fitting one of those isn't an option.
Very unlikely that fusebox is suitable for devices over 30A anyway.

That's right, the 45A option is a bigger carrier and not in line with the others.

 

[SUNRAY]

So I had the RCD in my hand and decided to change the habits of a lifetime and put it in the box with other 'saved' RCD's. I confess I'd forgotten I had these 2:

4 pole 40A & 25A alongside the previous device. Explains my earlier post about the size.

 

[Adam_151]

Is this hoarders annoymous?

There are at least two different sizes to the smaller form factor RCDs shown by sunray as well. Unfortunatly the picture below doesn't tell the full story, you'd be forgiven and thinking the smaller varient is upto and including 60A where-as the 80A and preumably 100A are bigger. There was a board with a WSES 63/2 which needed replacing, the WSES 63/2 below (note exact same part number) would not fit, it was about 10mm too narrow... the WSES 63/2 in that board was the size of the WSES 80/2 shown below

 

[MattB83]

Electrician called round today, one that came highly recommended by a plumber who has done some really good work for us - he pointed out that the wires have not just heated up but there are signs of a fire in the box.

Going to fit a new DB and new 10mm earth and take it from there.

I know a few people have mentioned that the shower cable should be 10mm but this guy says that if he was rewiring that's what he would use but it should be ok on 6mm cable.

This will sound ignorant but I hadn't distinguished REGISTERED from a QUALIFIED electrician.

 

[MattB83]

Took your advice:

https://photos.app.goo.gl/CqzFeWmjTsDvVo579