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Default Replacing Fuses with MCBs

Apologies for the lack of specifics here; I'm just at the stage of
finding out if this is feasible or not.

Currenly we have a traditional fusebox (fuses with fuse wire in ceramic
cylinder) installed and I wonder if it is possible to replace these
hoders with the circuit breaker type where a button pops out? Obviously
these things would have to be the same size and have the same fiitings.
Has anyone done this successfully or would I need a new fuse box?

My reason for asking is that every time one of the bulbs goes in my
kitchen light it takes out the fuse on the lighting circuit with it and
out go the downstairs lights. I'm getting a bit fed up of rewiring the
fuse.

Thanks

Tony

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mrcheerful
 
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Default Replacing Fuses with MCBs


wrote in message
oups.com...
Apologies for the lack of specifics here; I'm just at the stage of
finding out if this is feasible or not.

Currenly we have a traditional fusebox (fuses with fuse wire in ceramic
cylinder) installed and I wonder if it is possible to replace these
hoders with the circuit breaker type where a button pops out? Obviously
these things would have to be the same size and have the same fiitings.
Has anyone done this successfully or would I need a new fuse box?

My reason for asking is that every time one of the bulbs goes in my
kitchen light it takes out the fuse on the lighting circuit with it and
out go the downstairs lights. I'm getting a bit fed up of rewiring the
fuse.

Thanks

Tony


providing the right type is available, then yes, no problem, I even found
some for a really ancient fuse board.

mrcheerful


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John Rumm
 
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Default Replacing Fuses with MCBs

wrote:

Currenly we have a traditional fusebox (fuses with fuse wire in ceramic
cylinder) installed and I wonder if it is possible to replace these
hoders with the circuit breaker type where a button pops out? Obviously
these things would have to be the same size and have the same fiitings.
Has anyone done this successfully or would I need a new fuse box?


If you have the traditional Wylex type rewireable fuses:

http://www.tlc-direct.co.uk/Main_Ind...ex_Rewireable/

Then you can get plug in MCBs to replace these:

http://www.tlc-direct.co.uk/Main_Ind...nge/index.html

Note that they are all "B" type MCBs. These are the "normal" type of MCB
that has a quite fast response to fault conditions. Hence they will trip
as often (in fact probably more often) in response to bulbs blowing than
the rewireable fuses you currently have. Saves replacing fuse wire but
still a PITA!

If you replaced the consumer unit with a more modern one then you could
use type C MCBs for the lighting circuits. This may reduce the number of
times you get spurious trips.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
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bill
 
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Default Replacing Fuses with MCBs


"John Rumm" wrote in message
...
wrote:

Currenly we have a traditional fusebox (fuses with fuse wire in ceramic
cylinder) installed and I wonder if it is possible to replace these
hoders with the circuit breaker type where a button pops out? Obviously
these things would have to be the same size and have the same fiitings.
Has anyone done this successfully or would I need a new fuse box?


If you have the traditional Wylex type rewireable fuses:

http://www.tlc-direct.co.uk/Main_Ind...ex_Rewireable/

Then you can get plug in MCBs to replace these:

http://www.tlc-direct.co.uk/Main_Ind...nge/index.html

Note that they are all "B" type MCBs. These are the "normal" type of MCB
that has a quite fast response to fault conditions. Hence they will trip
as often (in fact probably more often) in response to bulbs blowing than
the rewireable fuses you currently have. Saves replacing fuse wire but
still a PITA!

If you replaced the consumer unit with a more modern one then you could
use type C MCBs for the lighting circuits. This may reduce the number of
times you get spurious trips.


--
Cheers,

John.


My fuse box has MEM stamped on the cover, would the Wylex type fit this or
is there an alternative.

thanks

Bill


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Alex
 
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Default Replacing Fuses with MCBs

John Rumm wrote:
If you have the traditional Wylex type rewireable fuses:

http://www.tlc-direct.co.uk/Main_Ind...ex_Rewireable/


Then you can get plug in MCBs to replace these:

http://www.tlc-direct.co.uk/Main_Ind...nge/index.html


Would such a replacement bring any safety benefit? My "new" (30 years
old) has such fuses instead of circuit breakers, and I'm worried about
the electrical safety of fuses vs circuit breakers.

Alex


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David Hansen
 
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Default Replacing Fuses with MCBs

On Tue, 1 Nov 2005 10:06:30 -0000 someone who may be "bill"
wrote this:-

My fuse box has MEM stamped on the cover, would the Wylex type fit this or
is there an alternative.


Probably not. http://www.memonline.com/uksales.html is the place to
start.





--
David Hansen, Edinburgh | PGP email preferred-key number F566DA0E
I will always explain revoked keys, unless the UK government
prevents me by using the RIP Act 2000.
  #7   Report Post  
David Hansen
 
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Default Replacing Fuses with MCBs

On Tue, 01 Nov 2005 11:07:42 +0000 someone who may be Alex
wrote this:-

Would such a replacement bring any safety benefit? My "new" (30 years
old) has such fuses instead of circuit breakers, and I'm worried about
the electrical safety of fuses vs circuit breakers.


You need to split fuses into two, rewirable and cartridge fuses.

Cartridge fuses are moderately expensive, break high currents
rapidly and are moderately easy to replace.

Circuit breakers (of the sort we are talking about here) are the
most expensive, break moderate currents in time [1] and are easy to
reset.

Rewirable fuses are cheap, only break low currents and are fiddly to
replace.

For most houses circuit breakers are the most sensible form of
protective device. One of the few downsides is that, if the house is
near a substation, in some types of fault the circuit breaker will
fail to operate properly and the main (cartridge) fuse will operate.
Cartridge fuses guard against such problems, but cannot be reset.


[1] for many years now manufacturers have said that some of their
circuit breakers will break high currents as rapidly as a cartridge
fuse. However, the graphs they use to make these claims stop before
the interesting bits.


--
David Hansen, Edinburgh | PGP email preferred-key number F566DA0E
I will always explain revoked keys, unless the UK government
prevents me by using the RIP Act 2000.
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John White
 
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Default Replacing Fuses with MCBs

On Tue, 01 Nov 2005 11:07:42 +0000, Alex
wrote:

John Rumm wrote:
If you have the traditional Wylex type rewireable fuses:

http://www.tlc-direct.co.uk/Main_Ind...ex_Rewireable/


Then you can get plug in MCBs to replace these:

http://www.tlc-direct.co.uk/Main_Ind...nge/index.html


Would such a replacement bring any safety benefit? My "new" (30 years
old) has such fuses instead of circuit breakers, and I'm worried about
the electrical safety of fuses vs circuit breakers.


There is no reason to assume that the fuses will be any less safe than
circuit breakers, assuming they were correctly installed in the first
place and have not been fiddled with.

The inherent problem with rewirable fuses is that you can rewire them
with just about anything. It is not uncommon to find that a fuse which
keeps blowing is "fixed" by putting in 30A wire instead of 5A. To a
lesser extent cartridge fuses can also be abused in this way.

The only case when I would definitely recommend replacing fuses with
MCBs on safety grounds is when the property is to be rented out, but
in such cases you would probably want to put in a split box anyway.

John
--
John White
SCA Electrical, Manchester http://www.scaelectrical.co.uk/
Domestic and commercial electrical contractors
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bill
 
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Default Replacing Fuses with MCBs


"David Hansen" wrote in message
...
On Tue, 1 Nov 2005 10:06:30 -0000 someone who may be "bill"
wrote this:-

My fuse box has MEM stamped on the cover, would the Wylex type fit this or
is there an alternative.


Probably not. http://www.memonline.com/uksales.html is the place to
start.


Thanks for that - didn't know what MEM meant

Bill


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Default Replacing Fuses with MCBs

David Hansen wrote:

Rewirable fuses have perfectly satisfactory breaking current ratings.

MCBs are prone to nuisance trips, fuses rarely are. If your fuse is
popping when the bulb goes, something isnt right. If you fit an mcb you
will have more nuisance trips, not less.

MCBs are generally reckoned to offer a bit more protection than fuses,
but its a fair bit less simple than that, and fuses have their plusses
too.

Its not usually necessary to go round replacing functioning fuses with
MCBs. If you want to worry about risks, getting hung up on trivia like
this is barking up the wrong tree. Your stairs are 100 times riskier.
Beds, roads, food, kitchens, power tools... not fuseboxes.

If youre using improperly ballotini fused bulbs and cant get decent
ones, a simple workaround is to put those lights on their own 3A fuse,
or better an mcb, between light fitting and CU. The 3A fuse is easily
replaced, or the mcb switched back on. Makes me wonder what kind of
bulbs youre using though.


NT



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Rumble
 
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Default Replacing Fuses with MCBs


snip
Thanks for that - didn't know what MEM meant

Midland Electric Manufacturing (or similar). The company has been around
for about 90 years.
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Norma
 
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Default Replacing Fuses with MCBs

On 1 Nov 2005 00:04:02 -0800, "
wrote:

Apologies for the lack of specifics here; I'm just at the stage of
finding out if this is feasible or not.

Currenly we have a traditional fusebox (fuses with fuse wire in ceramic
cylinder) installed and I wonder if it is possible to replace these
hoders with the circuit breaker type where a button pops out? Obviously
these things would have to be the same size and have the same fiitings.
Has anyone done this successfully or would I need a new fuse box?

My reason for asking is that every time one of the bulbs goes in my
kitchen light it takes out the fuse on the lighting circuit with it and
out go the downstairs lights. I'm getting a bit fed up of rewiring the
fuse.

Thanks

Tony

Tried from from Screwfix. Works fine but fuse box cover will not fit
-- MCB too proud.
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