Can I replace Fuse Wire units in Wylex 804 Ivy

[mikeanthony]

I am after some advice before I replace a Wylex 804 Ivy CU.

Can i just replace the individual fuse wire blocks with slot in units that will trip out?

Are these replacement units MCBs? and if so which ones best fit this type of CU?

Many thanks in advance.

Mike

 

[Taylortwocities]

Sure. here they are.. http://www.screwfix.com/prods/87979...-Incomers/Wylex-32A-SP-Type-B-Plug-In-MCB-3kA

But you are better off having someone swop out the old fuseboard with a new consumer unit that will provide supplementary protection (ie an RCD) for sockets etc.

 

[RF Lighting]

The maximum device for that CU is 30A

You can get a 45A device which is suitable for certain CUs, but not your model.

 

[mikeanthony]

thanks for your advice

Between my current Wylex 804 and the norweb electricity meter there is an Centaur ELCB 100/2/100 that has a singe trip out on it. This has tripped out in the past when i had a problem with a device plugged into one of the cellar power sockets so it has offered protection on ring main.

Does this mean that i dont need to put a new CU in if I just replace the fuseblocks with the MCBs you recommended or is there further advantage to having the CU replaced over and above this current Centaur ELCB arrangement + MCBs

Many thanks

Mike

 

[Taylortwocities]

Can we see a pic of the ELCB and the incoming power head?

Sounds like you may have a TT system and that has some special requirements.

If the ELCB has two earth leads on it (one in and one out) then it may be an old voltage type. These ELCBs are unreliable at best and are now obsolete and should be replaced.

 

[securespark]

They were deleted from the 15th ED. in 1985. They were (and indeed still are) deemed unsafe as they only detect earth leakage down the earthing conductors. If the leakage went through YOU to ground, then it would sit there quite happily without twitching...

 

[333rocky333]

Not sure think that is a 100ma rcd,
You should have 30ma rcd for the sockets though which wont fit the wylex.

someone will advise the best way as you might be better to do it the 17th edition way
ie 100ma for some and 30ma for others using the new style dual rcd boards

 

[plugwash]

They were deleted from the 15th ED. in 1985. They were (and indeed still are) deemed unsafe as they only detect earth leakage down the earthing conductors. If the leakage went through YOU to ground, then it would sit there quite happily without twitching...

So? the same would apply to a non-rcd circuit on a TN system. As I understand it the purpose of the ECLB is to provide protection against indirect contact as part of the EEBADs system not to provide protection against direct contact with live conductors.

However they are bad for another reason too, if another path takes away too much of the fault current (e.g. the earth rod is bad and there is another better earth from say a bonding connection) they may miss a fault.

 

[ban-all-sheds]

someone will advise the best way as you might be better to do it the 17th edition way
ie 100ma for some and 30ma for others using the new style dual rcd boards

So the myths and misinterpretations are spreading already, are they?

Just what does the 17th say about different requirements for CU designs?

 

[333rocky333]

Just what does the 17th say about different requirements for CU designs?

Dont know still waiting for the book

But surely if he is doing it, he might as well do it to the 17th if it is better rather than the 16th.

And have the latest model boards that seem to be out now.
I personally would

 

[ban-all-sheds]

Dont know still waiting for the book

So why say "you might be better to do it the 17th edition way" if you don't know that there is a "17th edition way" in the sense of any changes from the 16th?

 

[333rocky333]

ie 100ma for some and 30ma for others

I thought the 17th way, some other circuits may also now require 30 ma rcd, apart from some of the sockets.

 

[ban-all-sheds]

Indeed they do - buried cables for example, and special locations.

I'm not having a go at you - sorry if I seemed to be, but there seems to be an exaggerated belief that more circuits needing RCD protection actually means multiple independent sections in CUs, or RCBOs everywhere.

 

[333rocky333]

is there further advantage to having the CU replaced over and above this current Centaur ELCB arrangement + MCBs

Many thanks

Mike

Why replace this with a set up that will be out of date in july

If he rcd protects the RELEVANT circuits as per the 16th AND any extra that MAY be required in the 17TH regs now then it wont.

AS said SOMEONE will advise as it MAY be better

 

[333rocky333]

Ok bas
when I read back, I see what you mean