Replacing fuses with RCD’s

[scottpetrie]

I have an old fuse box in my house with old style fuses that need wire. Can I simply swap these out with RCD’s or do I have to change the entire fuse box? I work away so was just thinking of convenience for my wife if a fuse went and I wasnt there as she wouldnt know how to re-wire the blown fuse.

 

[ban-all-sheds]

I have an old fuse box in my house with old style fuses that need wire. Can I simply swap these out with RCD’s

You mean MCBs.

You can get plug-in MCB modules to replace those fuses (I'm assuming it's a Wylex board?), but they are expensive.

I work away so was just thinking of convenience for my wife if a fuse went and I wasnt there as she wouldnt know how to re-wire the blown fuse.

Fuses don't blow for no reason.

How many times have you had it happen?

 

[scottpetrie]

Ive only been in the house 9 months and its never actually happened. I just remember from the past Ive switched a light on and the bulbs popped and tripped the fuse. I suppose its a case if its not broke dont fix it. Was just a thought.

 

[ban-all-sheds]

I'll bet what happened was the failing bulb tripped an MCB. If you'd had fuses nothing would have happened.

If you are really concerned about your wife having to rewire a fuse, get some spares and leave them there ready wired. Or show her how to do it - she's a woman, not a goldfish, she has hands and a brain.

Just make sure you impress on her that it is ABSOLUTELY ESSENTIAL that she turns off the main switch before replacing one. As it would be if she rewired it herself.

 

[JohnD]

old-type lightbulbs with filaments sometimes trip MCBs when they burn out, there is a momentary power surge. Miniature lamps and spotlights seem more prone to it than traditional-shaped full size bulbs.

If you have kitchen downlighters, you might get it.

Since going over to energy saving, and more recently LED, lamps, I haven't experienced it at all.

 

[Doggit]

You can get replacement MCBs that fit into the old style fuse boxes, but I'd suggest a new consumer unit with an RCD would be a much better option. But, if you're consumer unit is that old, then a rewire may well be required soon, so a new consumer unit with an RCD will be a sensible protection till you get round to the rewire. Just don't let any leccy tell you it's all got to be done in one go.

 

[securespark]

If you'd had fuses nothing would have happened.

I beg to differ:

"Yes am talking 3036's. I was surprised too. The flat ws leased and the landlady rang me up every week to say that the lighting fuse was blowing.

in each case, I replaced the wire, switched back on and lo, a lamp had gone.

So in the end, I advised to throw all the existing lamps in the bin and go out & buy a shed-load of Osram - I swear by them.

They are double fused.

Those of you with a technical streak will know that good quality lamps have Ballotini fuses in them (named after the italian geezer that invented them). these blow in preference to the protective device when the lamp blows.

Any how, when they had installed Mr Osram's finest, the problem completely went away.....until they moved out!!!!!!"

Read more: https://www.diynot.com/diy/threads/which-consumer-unit.5878/page-2#ixzz5785GckAG

 

[Risteard]

I beg to differ:

"Yes am talking 3036's. I was surprised too.

I'm not surprised - I've seen it countless times both with 3036s and with 1361s.

 

[oldbutnotdead]

If it ain't broke, don't fix it. As above, rewirable fuses are simple to rewire (if you can still get the fuse wire- think I've got a card in the garage somewhere if you're stuck) and still do an adequate job of protecting the wiring. Tools needed- a torch (so you can see what you're doing with the main switch OFF), a small flat-bladed screwdriver and a set of wire cutters (you can just twist the fuse wire a few times til it snaps but cutters will be much neater and quicker).

In my old house I had rewirable fuses til last year, only got the CU swapped because I was renting the place out and got sharp intakes of breath from letting agents and tenants when they saw the old Wylex boards. In 25 years I had no fuses blow. RCD dropped out a few times (eventually found that the oven was FUBAR) but apart from that troublefree service.

Swapping a CU is notifiable work (due mainly to the amount of testing that has to be done), there is always a chance that the spark doing the job will 'discover' things that turn a £400 CU swap into a £4k rewire with tutting about 'can't reconnect this without doing xyz, I'd be breaking the law'

 

[mwatsonxx]

Swapping a CU is notifiable work (due mainly to the amount of testing that has to be done), there is always a chance that the spark doing the job will 'discover' things that turn a £400 CU swap into a £4k rewire with tutting about 'can't reconnect this without doing xyz, I'd be breaking the law'

Thats why you do test before changing the CU.

 

[ban-all-sheds]

Try reading it again:

there is always a chance that the spark doing the job will 'discover' things ....

 

[boringoldcodger]

if you can still get the fuse wire

Last time I looked in Robert Dyas and (in London) Ryness, they had carded fuse wire.

 

[mwatsonxx]

Try reading it again:

Has any village lost their idiot? We have a spare one here.

 

[Taylortwocities]

Don't be so hard on yourself.

 

[bernardgreen]

Those of you with a technical streak will know that good quality lamps have Ballotini fuses in them

A name from the past, quote from http://www.lamptech.co.uk/Documents/IN Fusing.htm which tells how and why some lamps become dangerous when the filament fails.
Ballotini Fusing
This is the safest and most reliable fuse type - but also the most expensive. The fuse wire is encapsulated in a small glass tube filled with tiny glass beads called Ballotini, named after Potters Ballotini, the Italian producer. Should a secondary arc form between the broken pieces of fuse wire, its heat will melt the glass beads to form an electrically insulating barrier which contains and rapidly quenches the arc. It is so efficient that only one fuse is required, but on account of their higher price they are generally employed only in the more expensive special lamps, or decorative lamps which are too small to be able to accommodate two sufficiently long bare fuses (e.g. candle and globe lamps).

Don't be so hard on yourself.

Don't worry, the poor lad is just con-fused