UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
the yorkshire dalesman
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

What are the pros & cons of the various makes (apart from cost) of
Consumer Unit?

eg the TLC catalog lists MK, Wylex and Contactum & there's others.

Is Contactum a TLC own-brand?

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.
  #3   Report Post  
BillR
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

the yorkshire dalesman wrote:
What are the pros & cons of the various makes (apart from cost) of
Consumer Unit?

eg the TLC catalog lists MK, Wylex and Contactum & there's others.

Is Contactum a TLC own-brand?

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.


I've recently fitted 2 of the Wylex 12 way spilt-load kits that Screwfix
sell. They seem good quality and easy to fit.
The kits were 70 quid but are now 75.
In both cases they replaced Wylex cartridge fuse type units that were still
going strong after 25+years.


  #5   Report Post  
Dave Stanton
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)


Just make sure you check the spec on the RCD - most devices bundled as
part of a split board seem to be 63A. If you really need 80A then 63 isn't
going to hack it.

Hwyl!

M.


Wylex do a split load cu with 80A RCD.

Dave

--
And you were born knowing all about ms windows....??



  #6   Report Post  
RichardS
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

"the yorkshire dalesman" wrote in message
om...
What are the pros & cons of the various makes (apart from cost) of
Consumer Unit?

eg the TLC catalog lists MK, Wylex and Contactum & there's others.

Is Contactum a TLC own-brand?

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.


No opinions as to makes, but if you want maximum flexibility for any changes
that you might make in the future, then consider installing a plain CU and
individual RCBOs or MCBs depending upon each individual circuit. This is
not a particularly cheap option, but one big advantage is that a leakage
fault in a circuit will take out only that circuit and not the entire
RCD-protected rail.

This is the way that I will go when I get round to replacing our CU this
year.


--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk


  #7   Report Post  
ARWadsworth
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)


"RichardS" noaccess@invalid wrote in message
. ..
"the yorkshire dalesman" wrote in message
om...
What are the pros & cons of the various makes (apart from cost) of
Consumer Unit?

eg the TLC catalog lists MK, Wylex and Contactum & there's others.

Is Contactum a TLC own-brand?

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.


No opinions as to makes, but if you want maximum flexibility for any

changes
that you might make in the future, then consider installing a plain CU and
individual RCBOs or MCBs depending upon each individual circuit. This is
not a particularly cheap option, but one big advantage is that a leakage
fault in a circuit will take out only that circuit and not the entire
RCD-protected rail.


It's not that expensive for what can be a much better solution, and don't
forget to leave some spare ways for expansion.

--
Adam



  #8   Report Post  
Andy R
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)


"RichardS" noaccess@invalid wrote in message
. ..
"the yorkshire dalesman" wrote in message
om...
What are the pros & cons of the various makes (apart from cost) of
Consumer Unit?

eg the TLC catalog lists MK, Wylex and Contactum & there's others.

Is Contactum a TLC own-brand?

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.


No opinions as to makes, but if you want maximum flexibility for any

changes
that you might make in the future, then consider installing a plain CU and
individual RCBOs or MCBs depending upon each individual circuit. This is
not a particularly cheap option, but one big advantage is that a leakage
fault in a circuit will take out only that circuit and not the entire
RCD-protected rail.

This is the way that I will go when I get round to replacing our CU this
year.


I was also thinking of doing this but I want rewireable/cartridge fuses for
the lighting circuits instead MCB/RCBO. Does anyone know of a CU with this
option?

TIA

Andy R


  #9   Report Post  
Lurch
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

[..]

I'm looking for a (plastic cased) 12 to 15 way split load (80A
RCD/100A plain) preferably with a moveable division, but would also
consider separate RCD & plain units. Price matters but not nearly so
much as quality - ie I don't want to have to replace it again (ever -
if eternity exists).

many thanks for any advice/experience/views.


No opinions as to makes, but if you want maximum flexibility for any

changes
that you might make in the future, then consider installing a plain CU and
individual RCBOs or MCBs depending upon each individual circuit. This is
not a particularly cheap option, but one big advantage is that a leakage
fault in a circuit will take out only that circuit and not the entire
RCD-protected rail.

This is the way that I will go when I get round to replacing our CU this
year.


I was also thinking of doing this but I want rewireable/cartridge fuses for
the lighting circuits instead MCB/RCBO. Does anyone know of a CU with this
option?

I have always used Hager. I've been fitting them since I was an
apprentice. You can get all sorts of different CPD's - MCB's, RCBO's,
HRC's and all types of each. Top quality, good price.
You could even put all of your heating and lighting controllers in
there too along with a built in emergency light but that may be a
little excessive for what you want!
  #10   Report Post  
Owain
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

"Andy R" wrote
| I was also thinking of doing this but I want rewireable/cartridge
| fuses for the lighting circuits instead MCB/RCBO. Does anyone
| know of a CU with this option?

Why anyone would want rewireable fuses is beyond me[1] and remember that if
you do use them the cables must be derated.

Owain

[1] If you have a problem with blown bulbs tripping MCB then get decent
light fittings and not some electrolier that thinks it's still the 1930s



  #11   Report Post  
Andy R
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)


"Owain" wrote in message
...
"Andy R" wrote
| I was also thinking of doing this but I want rewireable/cartridge
| fuses for the lighting circuits instead MCB/RCBO. Does anyone
| know of a CU with this option?

Why anyone would want rewireable fuses is beyond me[1] and remember that

if
you do use them the cables must be derated.


Why anyone would want MCBs that trip every time a light bulb goes is beyond
me. Trekking out to the garage in the dark to reset an MCB isn't my idea of
fun. I've got young kids and if all the lights go out they come running
down the stairs in the dark to find out what's happening. A real fault in
the lighting circuit is extremely rare so it's extremely unlikely I'd ever
have to replace the fuse.

The quality of the light fitting has little to do with the MCB tripping,
there was an excellent explanation of why a bulb failing trips the MCB
posted IIRC by Andrew Gabriel some time ago. A Google search should find
it.

Rgds

Andy R


  #12   Report Post  
N. Thornton
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

"Andy R" wrote in message ...
"Owain" wrote in message


| I was also thinking of doing this but I want rewireable/cartridge
| fuses for the lighting circuits instead MCB/RCBO. Does anyone
| know of a CU with this option?


Why anyone would want rewireable fuses is beyond me[1] and remember that

if
you do use them the cables must be derated.


Why anyone would want MCBs that trip every time a light bulb goes is beyond
me. Trekking out to the garage in the dark to reset an MCB isn't my idea of
fun. I've got young kids and if all the lights go out they come running
down the stairs in the dark to find out what's happening. A real fault in
the lighting circuit is extremely rare so it's extremely unlikely I'd ever
have to replace the fuse.

The quality of the light fitting has little to do with the MCB tripping,
there was an excellent explanation of why a bulb failing trips the MCB
posted IIRC by Andrew Gabriel some time ago. A Google search should find
it.



Indeed, wire fuses are safer than MCBs on light circuits (only). There
are safety pros and cons for each option, but repeated loss of lights
is the biggest risk, and wire fuses avoid that.

They are also more convenient, as wire fuses rarely blow. When they
do, downtime is longer, but a 2 or 3 minute outage per 20 years is a
lot better than monthly 1 minute darkouts.


Regards, NT
  #13   Report Post  
Lurch
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)


Indeed, wire fuses are safer than MCBs on light circuits (only). There
are safety pros and cons for each option, but repeated loss of lights
is the biggest risk, and wire fuses avoid that.

They are also more convenient, as wire fuses rarely blow. When they
do, downtime is longer, but a 2 or 3 minute outage per 20 years is a
lot better than monthly 1 minute darkouts.


I wouldn't say they were safer on any circuit, (I assume you're on
about rewirable, not HRC), I certainly wouldn't recommend them in any
situation. I have fitted many HRC fuses and have only had them blowing
under fault conditions, very rarely because 1 bulb has blown.
Rewirable are next to useless in any situation, damn near blinded me
because of rewirable fuses, but thats another story!


SJW
A.C.S. Ltd.
  #14   Report Post  
Owain
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

"N. Thornton" wrote
| Indeed, wire fuses are safer than MCBs on light circuits (only).
| There are safety pros and cons for each option, but repeated
| loss of lights is the biggest risk, and wire fuses avoid that.

Because they provide a lower standard of electrical protection.

Loss of lights is a risk which can be avoided by proper circuit arrangements
(more than one lighting circuit per storey, if not per room) and the
provision of ELUs at hazard spots (stairs and kitchen) together with proper
selection of luminaires. Tripping MCBs on bulb failure is an excellent
additional reason for avoiding mains voltage incandescent lighting.

| They are also more convenient, as wire fuses rarely blow. When
| they do, downtime is longer,

As long as it takes to find some 4mm cable to rewire the fuse with.

Owain



  #15   Report Post  
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

In uk.d-i-y, Owain wrote:
| There are safety pros and cons for each option, but repeated
| loss of lights is the biggest risk, and wire fuses avoid that.

Because they provide a lower standard of electrical protection.

I don't think anyone's been seriously arguing for "semi-enclosed
rewirable have-your-eye-out put-a-nail-in" fuses; but there's certainly
a very legitimate place for cartridge fuses, which have usefully different
time characteristics and current-breaking capacities to circuit breakers.
For domestic lighting circuits as found in established UK wiring practice,
I'd agree with Nick that there's a pragmatic safety gain to replace an
MCB (esp. a 'B'-characteristic quick-trip one) with a physically compatible
DIN-rail fuseholder fitted with an appropriate cartridge fuse. MEM, for one,
sell these as a standard CU accessory.

Stefek


  #16   Report Post  
N. Thornton
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

Hi folks.


From Lurch:

I have fitted many HRC fuses and have only had them blowing
under fault conditions, very rarely because 1 bulb has blown.


Exactly how they should behave. MCBS OTOH misbehave routinely.

Rewirable are next to useless in any situation,


That isnt credible. They do exactly whats needed, and meet all the
latest requirements.


damn near blinded me
because of rewirable fuses, but thats another story!


I have a feeling you have a story to tell us

There are /un/enclosed wire fuses that I've seen in extremely old
installs that are a risk, but where theyre covered up by the ceramic
holder, as in any modern or even semi modern CU, fuse wire explosion
is not a problem. I await your story, but meanwhile dont forget that
one case of almost injury proves nothing, since MCBs are also known to
cause injury through stair falls.


From: Owain )
"N. Thornton" wrote

| Indeed, wire fuses are safer than MCBs on light circuits (only).
| There are safety pros and cons for each option, but repeated
| loss of lights is the biggest risk, and wire fuses avoid that.


Because they provide a lower standard of electrical protection.


Their trip characteristics are very different, but under fault
conditions they do their job. They dont cause a problem there.

A trip device that does not cause numerous unwanted and sometimes
dangerous trips is a better standard of protection.


Loss of lights is a risk which can be avoided by proper circuit

arrangements
(more than one lighting circuit per storey, if not per room) and the
provision of ELUs at hazard spots (stairs and kitchen) together with

proper
selection of luminaires. Tripping MCBs on bulb failure is an

excellent
additional reason for avoiding mains voltage incandescent lighting.


It could, but this is all very unrealistic. You can specify that for
some commercial installs or a few rich householders, but in the real
world you just wont find that in most houses. Few will meet all that.


| They are also more convenient, as wire fuses rarely blow. When
| they do, downtime is longer,


As long as it takes to find some 4mm cable to rewire the fuse with.


Thats their one downside, and is easily resolved by putting a fuse
wire card on the CU. That is a far more workable and easier solution
than your suggestion above.


From: )

but there's certainly
a very legitimate place for cartridge fuses, which have usefully

different
time characteristics and current-breaking capacities to circuit

breakers.
For domestic lighting circuits as found in established UK wiring

practice,
I'd agree with Nick that there's a pragmatic safety gain to replace

an
MCB (esp. a 'B'-characteristic quick-trip one) with a physically

compatible
DIN-rail fuseholder fitted with an appropriate cartridge fuse. MEM,

for one,
sell these as a standard CU accessory.


Indeed, it removes 99% of a very well known risk, one that injures and
kills people.

Rewirable fuses remove that risk too, though they also have the
potential for miswiring. Even there, one has to look at the relative
risks. I dont know what the stats are, ie:
in how many places rewirables are miswired,
how many of those lead to fire or shock,
and how many injuries and deaths result from those.
I also dont know the stats for MCB-caused accidents and deaths, due to
loss of lighting and subsequent falls down stairs, failures to get out
of fires alive, welding of the MCB contacts, trip mechanism failure,
deliberate miswiring as a result of nuisance trips, etc.

I would not rush to assume that MCBs are safer on lighting circuits
until I actually knew the figures. From what little I know, I am
fairly convinced that cart fuses are safer than MCBs on lighting, and
I expect rewirable fuses may well be too.

Until we get the figures, it is impossible to actually know. Assuming
that quicker fault disconnects and less overcurrent tolerance leads to
greater safety is in truth an assumption rather than a fact.


Regards, NT
  #17   Report Post  
Lurch
 
Posts: n/a
Default Choosing a Consumer Unit (Electrical)

On 14 Jan 2004 06:07:21 -0800, (N. Thornton) wrote:

Hi folks.


From Lurch:

I have fitted many HRC fuses and have only had them blowing
under fault conditions, very rarely because 1 bulb has blown.


Exactly how they should behave. MCBS OTOH misbehave routinely.

Rewirable are next to useless in any situation,


That isnt credible. They do exactly whats needed, and meet all the
latest requirements.


Given the reliability of HRC's as mentioned at the top of this post
there is no reason to use rewirable. Although they might comply with
current regulations I still wouldn't use them on the grounds that they
are far less liable to provide adequate protection and given the
non-modular arrangement of rewirable CU's they will not tie into a new
installation so MCB's and/or HRC's would be far more suitable.


damn near blinded me
because of rewirable fuses, but thats another story!


I have a feeling you have a story to tell us

Long story short, working on a cooker switch, someone else put fuse
back in, (rewirable!), as I reached into the back of the cooker box
the live and earth welded together, blinding flashes and minor burns,
hospital treatment required. Even with L&E welded together on the end
of a 6mm cable no more than 10m from the board the 30A rewirable fuse
never blew.
There are /un/enclosed wire fuses that I've seen in extremely old
installs that are a risk, but where theyre covered up by the ceramic
holder, as in any modern or even semi modern CU, fuse wire explosion
is not a problem. I await your story, but meanwhile dont forget that
one case of almost injury proves nothing, since MCBs are also known to
cause injury through stair falls.


Quite right, but in case of electrical faults, MCB's would offer
better protection. As you say there are pro's and con's to each type
of CPD. I have all MCB's in my own house bar the lighting covering the
stairs which is protected by a HRC.


From: Owain )
"N. Thornton" wrote

| Indeed, wire fuses are safer than MCBs on light circuits (only).
| There are safety pros and cons for each option, but repeated
| loss of lights is the biggest risk, and wire fuses avoid that.


When you say wire fuses do you mean HRC or rewirable?

Because they provide a lower standard of electrical protection.


Their trip characteristics are very different, but under fault
conditions they do their job. They dont cause a problem there.


Not neccessarily, see above! I have been on jobs before with a
rewirable board, with the wiring in a lethal state. Surprisingly,
(not), not one fuse had blown. With MCB's and RCD's this dangerous
installation would have had attention before because of MCB's tripping
etc. With HRC's the faults probably wouldn't have shown up as quickly,
but they would.

A trip device that does not cause numerous unwanted and sometimes
dangerous trips is a better standard of protection.


Loss of lights is a risk which can be avoided by proper circuit

arrangements
(more than one lighting circuit per storey, if not per room) and the
provision of ELUs at hazard spots (stairs and kitchen) together with

proper
selection of luminaires. Tripping MCBs on bulb failure is an

excellent
additional reason for avoiding mains voltage incandescent lighting.


It could, but this is all very unrealistic. You can specify that for
some commercial installs or a few rich householders, but in the real
world you just wont find that in most houses. Few will meet all that.

As I say, HRC's on lighting circuits.
| They are also more convenient, as wire fuses rarely blow. When
| they do, downtime is longer,


As long as it takes to find some 4mm cable to rewire the fuse with.


Thats their one downside,


Think you'll find there's more than one downside.

and is easily resolved by putting a fuse
wire card on the CU. That is a far more workable and easier solution
than your suggestion above.


From:
)

but there's certainly
a very legitimate place for cartridge fuses, which have usefully

different
time characteristics and current-breaking capacities to circuit

breakers.
For domestic lighting circuits as found in established UK wiring

practice,
I'd agree with Nick that there's a pragmatic safety gain to replace

an
MCB (esp. a 'B'-characteristic quick-trip one) with a physically

compatible
DIN-rail fuseholder fitted with an appropriate cartridge fuse. MEM,

for one,
sell these as a standard CU accessory.


Indeed, it removes 99% of a very well known risk, one that injures and
kills people.

Rewirable fuses remove that risk too,


Yes, but they also dont really provide much protection under fault
conditions.
though they also have the
potential for miswiring. Even there, one has to look at the relative
risks. I dont know what the stats are, ie:
in how many places rewirables are miswired,
how many of those lead to fire or shock,
and how many injuries and deaths result from those.
I also dont know the stats for MCB-caused accidents and deaths, due to
loss of lighting and subsequent falls down stairs, failures to get out
of fires alive, welding of the MCB contacts, trip mechanism failure,
deliberate miswiring as a result of nuisance trips, etc.

I would not rush to assume that MCBs are safer on lighting circuits
until I actually knew the figures. From what little I know, I am
fairly convinced that cart fuses are safer than MCBs on lighting, and
I expect rewirable fuses may well be too.

Until we get the figures, it is impossible to actually know. Assuming
that quicker fault disconnects and less overcurrent tolerance leads to
greater safety is in truth an assumption rather than a fact.




SJW
A.C.S. Ltd.
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
wiring diagram for consumer unit Carlos Nazoa Ruiz UK diy 3 December 15th 03 12:56 PM
Fitting a Wylex Consumer unit with spur to shed [email protected] UK diy 3 December 10th 03 01:05 PM
Wiring of new Consumer Unit Tipu Sattar UK diy 9 November 30th 03 11:31 AM
old circuits, new consumer unit David Robinson UK diy 5 September 5th 03 11:49 AM
F&G Concept 2000 Consumer Unit Live Busbar Query Andy Taylor UK diy 1 September 3rd 03 01:52 PM


All times are GMT +1. The time now is 09:58 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"