Upgrading Wylex re-wrirable fuses to MCBs

[Ali3nat0r]

Hi, I planned on replacing all the fuses in my consumer unit with MCBs. I found some on eBay for cheap which were listed as working so I got those, but the pin spacing is different to the old fuses. They didn't come with the base socket so is it just going to be a case of getting a new socket from somewhere, or have I bought something I can't use? Picture attached to show size difference.

 

[Rampage]

Different protective devices require different Zs values, it needs to be checked. I doubt a competant DIY'er would know what this is, so no, it should be done by an electrician.
This is in general not just this situation.

Also, would someone buying a MCB know the difference between B/C/D types? (not relevant I know)

 

[Ali3nat0r]

i agree with wp. inasmuch as a competent diy'er can do this job. it's not a big step up from changing a blown fuse. OK , a spark would take readings of the circuits to confirm disconnection times and safety issues, but we are in danger of pandering to the nanny state if being too strict in advising diy-ers not to do anything in their own homes. what concerns me more is the possibility that these 2nd hand MCBs might have been hammered and the OP has no way of testing them.

I like to think I'm a competent DIY'er, I've replaced some of our light switches and fittings with no problems. It's common sense really that if you don't know if something's live you don't touch it until you've checked it with a DMM. Might be a good point that the MCBs may have been hammered, he said he took them out of a working CU though. I might message him see if he has the holders or not.

 

[Deleted member 26818]

The maximum permissable Zs for a 20A and a 32A MCB are higher than those for a 20A and 30A BS3036 fuse.
As such if the Zs are too high for the MCBs, they would be too high for the fuses.
Yes the maximum permissable Zs for a 6A MCB is lower than that allowed for a 5A BS3063 fuse, however in many instances lighting circuits do not have a CPC, so measuring Zs is often moot.

 

[Rockingit]

Hmmm....I'm hanging in with everyone's various thoughts and not particularly falling one side of the fence or other, but it kind of occurs to me that exactly how much of a consumer unit do we have to change, part by part, screw by screw, until we end up with having done a CU change in all but name?

It's a bit like Trigger's original brush that's only had 5 new handles and 3 new heads.

 

[Rockingit]

I also note that the OP has used the letters DMM and no-one has yet to mention GS38.

 

[Deleted member 9648]

I do feel when it comes to DIY electrics many on here take a 'Not in my back yard' view....I've made the point before....many of the 'not in my back yarders' will happily change the brakes on their vehicle instead of using a qualified mechanic,the hypocracy seems to be lost on them.....Clearly a great deal of domestic electrics should be carried out by qualified people...but plug in MCB's?..it aint rocket science.

 

[Specialist]

It's common sense really that if you don't know if something's live you don't touch it until you've checked it with a DMM.

Just a point to note: A DMM is not considered as a safe & reliable way of proving safe isolation of a circuit.

 

[telectrix]

but neither is a neon screwdriver, but i'll bet a lot of diy-ers rely on them.

 

[Specialist]

but neither is a neon screwdriver, but i'll bet a lot of diy-ers rely on them.

Now, Now no swearing please. Lol

 

[Engineer54]

I also note that the OP has used the letters DMM and no-one has yet to mention GS38.

Why should he have GS38 probes, this is his own DMM it's not as if he is plying his DIY for gain outside of his own home!!!

Again, we old one's must have been living charmed lives all these years before the advent of GS38 probes came about!! ...lol!! I'm not saying that they aren't an improvement on the old probes etc, but you can take these things far too far!!!

 

[Specialist]

Why should he have GS38 probes, this is his own DMM it's not as if he is plying his DIY for gain outside of his own home!!!

Again, we old one's must have been living charmed lives all these years before the advent of GS38 probes came about!! ...lol!! I'm not saying that they aren't an improvement on the old probes etc, but you can take these things far too far!!!

I still prefer the probes on my old AVO 8, but I suppose we've gotta go with the times. Might get a smacked wrist otherwise Lol. On a serious note though i've seen a lot of these cheap import DMM's & would'nt advise anyone to use 1 for testing on live mains, at least useing a probe to GS38 you should be assured that it's of good quality & safe to use.

 

[Engineer54]

How often do you take you Avo 8 out onto a job these days?? Not often i suspect, so why would you bother, if it's now basically a home based test kit?? I have an Avo 8, in fact have a Avo 7 too, and i wouldn't dream of changing the leads on them!!!

 

[Specialist]

How often do you take you Avo 8 out onto a job these days?? Not often i suspect, so why would you bother, if it's now basically a home based test kit?? I have an Avo 8, in fact have a Avo 7 too, and i wouldn't dream of changing the leads on them!!!

Yep i've got a 7 too, use the 8 on the repair bench in the workshop. Both have original AVO leads, the only reason I don't take them on site is that I could'nt replace them.