UP GRADE OF CONSUMER UNIT

by **greengrass** » Thu Mar 12, 2009 9:20 pm

Existing Wylex 8 way consumer unit installed around 1980 tested safe.
Thinking of replacing wired fuses with Wylex plug in MCB's
I know they will stick out further but that’s sorted with an extra deep cover.
Is there any ‘for and against ‘ using this type of MCB?

Our suppliers sub-contractor offered free visual inspection and made a Bee line for the C.U and condemned it as dangerous because it’s a wire fuse type unit. It is not its just a pain in the butt to re-wire when they blow. Yes I know the difference it trips in milliseconds with MCB, longer with wire fuse but operationally fine as long as correct fuse wire used.

by **kbrownie** » Fri Mar 13, 2009 12:21 pm

nothing wrong with BS3036 rewireable fuses as long as correct fuse rated wire is replaced as mentioned and also the derating factors will increase your cables csa.
The draw back is having to rewire them rather than reset them as you would with an MCB.

I'm sure BS3036 operate quicker?
KB

by **greengrass** » Fri Mar 13, 2009 1:09 pm

[quote="kbrownie"]nothing wrong with BS3036 rewireable fuses as long as correct fuse rated wire is replaced as mentioned and also the derating factors will increase your cables csa.
The draw back is having to rewire them rather than reset them as you would with an MCB.

I'm sure BS3036 operate quicker?
KB[/quote]

From Greengrass
I don't think you got the message I want to replace the Wylex re-wireable ones with the Wylex MCB type with trip switch rather than having to pull a blown fuse out while unit still live as they seem to blow at night when lights needed.

by **kbrownie** » Fri Mar 13, 2009 6:21 pm

I understood what your message said but the electrician who inspected your system is wrong. I agree that mcb replacement are less hasle to reset but rewireable fuses are not dangerous may be a little dated but no more dangerous than anything else as long fitted and fused correctly.
KB

by **stoneyboy** » Fri Mar 13, 2009 8:21 pm

greengrass,
Go for the mcbs, the only down side is on the lighting circuit where you will find a blown lamp will frequently trip the 6a mcb.
end

by **sparx** » Fri Mar 13, 2009 9:23 pm

Hi ,
plug in replacements are fine and most fuse covers have a 'breakout' section of the front, which with a little filing will still fit with just the front of mcb sticking out,
regards SPARX

by **ban_all_sheds** » Fri Mar 13, 2009 9:58 pm

have you got or do you want rcd protection?

why are you having to replace the fuse wires in your carriers?

Is your installation "tested as safe"?

Just get a new 17th edition BS7671:2008 dual split consumer unit if safety is on your mind.

Do you intend to do this yourself or employ an electrician?

It is debatable whether replacing "plug in MCBs" for Bs3061 rewireable fuses is notifiable?

If you have had a periodic report stating your installation is safe then fine.
but consider the benefits of RCD protection