DIY Forum

 

Ultimate Handyman Ultimate Handyman Ultimate Handyman Ultimate HandymanUltimate Handyman on Pinterest

 

DIY Forum/Home improvement advice forum

 

 

A-Z CONTENTS | DISCLAIMER | DIY VIDEO | HOME | SAFETY FIRST | FORUM RULES

It is currently Sun Jan 21, 2018 10:59 am
Visit Thermo worx


Time zone: Europe/London




 

 


Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: MCB not working..
PostPosted: Wed Feb 01, 2017 10:54 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
About a year ago an electrician fitted an extra mcb to the consumer unit [CU]in the garage ,the CU is a Hager 17th edition as fitted to new houses in 2010. Seems the mcb is not working properly as it is tripping all the time, can anyone explain please how and what precautions I need to take when fitting a new one. I'm swapping over for new as I havent a clue how to test it out of the CU .. Is it just a case of switching the CU off at the on/off switch or is their further tests to do before I can exchange the mcb?


Share on FacebookShare on TwitterShare on DiggShare on DeliciousShare on Google+
Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Wed Feb 01, 2017 11:25 pm 
Offline
Pro Carpenter
User avatar

Joined: Sat Dec 16, 2006 10:11 pm
Posts: 19829
Location: redhill surrey an auld reekie laddie
Has thanked: 644 times
Been thanked: 1820 times
what size and type is the mcb
what load is on it when it trips
is it in the house or in the garage ??

_________________
we are all ------------------still learning


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Wed Feb 01, 2017 11:45 pm 
Offline
Senior Member

Joined: Mon Dec 19, 2016 11:56 am
Posts: 234
Has thanked: 11 times
Been thanked: 56 times
:welcomeuhm: Are you sure it is an mcb and not an rcbo which is an mcb and rcd combined. Also could it be that there is a short circuit or earth fault on either the wiring on that circuit ie nail through cable etc or some faulty equipment used on that circuit ie cooker/kettle light fitting etc, and not a fault with the mcb or rcbo?.


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Thu Feb 02, 2017 10:03 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
Morbius wrote:
:welcomeuhm: Are you sure it is an mcb and not an rcbo which is an mcb and rcd combined. Also could it be that there is a short circuit or earth fault on either the wiring on that circuit ie nail through cable etc or some faulty equipment used on that circuit ie cooker/kettle light fitting etc, and not a fault with the mcb or rcbo?.

It is an mcb and it controls outside sockets, no nails through anything as cable [armoured] runs down the wall, two rcd's one for lighting one for sockets either side are mcbs on each side, please see the picture of inside CU I have taken. thanks.


Attachments:
IMG_2350 (FILEminimizer) 1.jpg
IMG_2350 (FILEminimizer) 1.jpg [ 186.18 KiB | Viewed 1224 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Thu Feb 02, 2017 10:18 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
big-all wrote:
what size and type is the mcb
what load is on it when it trips
is it in the house or in the garage ??

Please see picture I have provided, Consumer unit is in the garage..Thought that this might just be a matter of dropping the on/off switch to off so that the CU unit was no longer live, the only thing then being live with CU in the off position at the switch, would be the supply from the electricity board. So then I should be able to work safely taking the mcb out and replace it with the new one, job done ?


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Fri Feb 03, 2017 5:38 am 
Online
Senior Member

Joined: Sat Sep 01, 2012 7:03 pm
Posts: 6839
Has thanked: 37 times
Been thanked: 1154 times
MCB's are a safety device, if you do change it chances are the new one will still trip as it is detecting the same fault the existing one is.

As its controlling outside sockets why don't you switch everything off and open each socket in turn, have a look and see what you can see. You should be looking for loose wires, corrosion, damp / water, cable damaged, collection of insects.

_________________
Take it easy, a forum is only a collection of opinions. Above, are mine.

Which is correct? Metre or Meter? Click the link. to find out more.

No such thing as "Thou shalt put this wire here, Thou shalt put that wire there" .............Take a picture BEFORE you do the job.

If gloom had a voice, it would be me. :mrgreen:

:idea1: How to post a picture on this forum Click here


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Fri Feb 03, 2017 6:32 pm 
Offline
Approved Electrician

Joined: Sun Apr 24, 2011 7:01 pm
Posts: 2417
Location: South Yorkshire
Has thanked: 147 times
Been thanked: 520 times
alladinsane wrote:
big-all wrote:
what size and type is the mcb
what load is on it when it trips
is it in the house or in the garage ??

Please see picture I have provided, Consumer unit is in the garage..Thought that this might just be a matter of dropping the on/off switch to off so that the CU unit was no longer live, the only thing then being live with CU in the off position at the switch, would be the supply from the electricity board. So then I should be able to work safely taking the mcb out and replace it with the new one, job done ?


I cannot tell from that picture which MCB is tripping


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Fri Feb 03, 2017 9:19 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
OnlyMe wrote:
alladinsane wrote:
big-all wrote:
what size and type is the mcb
what load is on it when it trips
is it in the house or in the garage ??

Please see picture I have provided, Consumer unit is in the garage..Thought that this might just be a matter of dropping the on/off switch to off so that the CU unit was no longer live, the only thing then being live with CU in the off position at the switch, would be the supply from the electricity board. So then I should be able to work safely taking the mcb out and replace it with the new one, job done ?


I cannot tell from that picture which MCB is tripping

Looking at the photo of the Consumer Unit,please note nothing is marked,however taking it from the left I have found the mcbs on the left with the rcd control sockets etc, looking to the right that rcd and mcbs control the lighting etc.Now going back to to the immediate left,that particular rcd, the mcb next to it is the one that trips. if you look closely you will see armour cable, the black wire [neutral flagged] goes to the neutral bar at the top and the grey wire [flagged green yellow] goes to the earth bar, the live brown goes into the mcb mentioned, which makes two that are in there.I have discovered that this brown wire in this mcb works the socket inside the garage, the other works the outside socket. .


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Fri Feb 03, 2017 9:32 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
someone-else wrote:
MCB's are a safety device, if you do change it chances are the new one will still trip as it is detecting the same fault the existing one is.

As its controlling outside sockets why don't you switch everything off and open each socket in turn, have a look and see what you can see. You should be looking for loose wires, corrosion, damp / water, cable damaged, collection of insects.

I had already done all that, my oversight forgot to include that in the message sorry


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Sat Feb 04, 2017 12:01 am 
Offline
Senior Member

Joined: Mon Dec 19, 2016 11:56 am
Posts: 234
Has thanked: 11 times
Been thanked: 56 times
Looks like it's a 32 amp, is it a ring main ?. Have you checked the tightness of the terminals, just in case ?.


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Sun Feb 05, 2017 10:20 am 
Offline
Approved Electrician

Joined: Sun Apr 24, 2011 7:01 pm
Posts: 2417
Location: South Yorkshire
Has thanked: 147 times
Been thanked: 520 times
alladinsane wrote:
Looking at the photo of the Consumer Unit,please note nothing is marked,however taking it from the left I have found the mcbs on the left with the rcd control sockets etc, looking to the right that rcd and mcbs control the lighting etc.Now going back to to the immediate left,that particular rcd, the mcb next to it is the one that trips. if you look closely you will see armour cable, the black wire [neutral flagged] goes to the neutral bar at the top and the grey wire [flagged green yellow] goes to the earth bar, the live brown goes into the mcb mentioned, which makes two that are in there.I have discovered that this brown wire in this mcb works the socket inside the garage, the other works the outside socket. .


OK. So there is one socket in the garage and one outside socket (fed via the SWA)?

Personally I would move one of the cables from the tripping MCB to the MCB to the left and see what happens.

If you want to swap the MCB you probably should be looking at fitting a 20A one (it keeps people happy).
To swap the MCB turn off the main switch, fully slacken off the screw at the bottom of the MCB, pull down the plastic catch on the bottom of the MCB and you should be able to wriggle out the MCB.

Failing that then unscrew all the bottom screws on the LHS MCBs and remove the bus bar (replacement is the reversal)

And if your CU is unlabelled then now is a good time to label it up.



For this message the author OnlyMe has received gratitude : alladinsane
Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Sun Feb 05, 2017 11:41 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
OnlyMe wrote:
alladinsane wrote:
Looking at the photo of the Consumer Unit,please note nothing is marked,however taking it from the left I have found the mcbs on the left with the rcd control sockets etc, looking to the right that rcd and mcbs control the lighting etc.Now going back to to the immediate left,that particular rcd, the mcb next to it is the one that trips. if you look closely you will see armour cable, the black wire [neutral flagged] goes to the neutral bar at the top and the grey wire [flagged green yellow] goes to the earth bar, the live brown goes into the mcb mentioned, which makes two that are in there.I have discovered that this brown wire in this mcb works the socket inside the garage, the other works the outside socket. .


OK. So there is one socket in the garage and one outside socket (fed via the SWA)?

Personally I would move one of the cables from the tripping MCB to the MCB to the left and see what happens.

If you want to swap the MCB you probably should be looking at fitting a 20A one (it keeps people happy).
To swap the MCB turn off the main switch, fully slacken off the screw at the bottom of the MCB, pull down the plastic catch on the bottom of the MCB and you should be able to wriggle out the MCB.

Failing that then unscrew all the bottom screws on the LHS MCBs and remove the bus bar (replacement is the reversal)

And if your CU is unlabelled then now is a good time to label it up.


I think, that is trying to read between the lines you have wrote, that this job has not been done properly, and so having a rethink I just let this electrician get on with it at the install,silly me should have supervised lol, but in reality up until recently I had not a clue about a CU and really didn't want to find out the hard way, but yes I take your point and I will label the CU's workings as to what does what, but I must comment and ask, isn't this done at after build time to help the householder know what works what.

So what your saying is on the flick of the switch to the off position, [the switch at the extreme right of the pic coloured red] makes all except the 'mains in' which is from the Electricity Board dead, no live connection at all inside..please just endorse what I have concluded with and then I am good to go, and I will try swopping the wire to the other mcb as you suggest first, and thanks ever so much for the information. .


Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Mon Feb 06, 2017 6:36 pm 
Offline
Approved Electrician

Joined: Sun Apr 24, 2011 7:01 pm
Posts: 2417
Location: South Yorkshire
Has thanked: 147 times
Been thanked: 520 times
If you turn off the main switch, the red one on the very right then you are as you said "good to go".

A CU really should have the MCBs labelled up correctly. This should have been done when the CU was installed.

I don't believe an electrician installed a new MCB, I think he just added your new outside socket to the existing garage socket MCB!

And if you are unsure of anything then stop and post again.



For this message the author OnlyMe has received gratitude : alladinsane
Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Mon Feb 06, 2017 11:07 pm 
Offline
Newly registered Member

Joined: Sun Jul 29, 2012 10:22 pm
Posts: 90
Has thanked: 42 times
Been thanked: 3 times
OnlyMe wrote:
If you turn off the main switch, the red one on the very right then you are as you said "good to go".

A CU really should have the MCBs labelled up correctly. This should have been done when the CU was installed.

I don't believe an electrician installed a new MCB, I think he just added your new outside socket to the existing garage socket MCB!

And if you are unsure of anything then stop and post again.


Thank you , Do you think I should put the outside socket on its own mcb, as it seems there are plenty of available places[ways] left for the inserts, would need to obtain an mcb, though that should not be a problem, but what size please ?

I thought when you indicated move the brown wire to the next mcb it was to eliminate something that was done wrong on install, not the way you would have done it is it! We pay our money and leave to trust and only when there are problems do we find short cuts that have been taken,but I am not dying for any mistake unless I make it.. Much the same as nothing is labelled on this CU unit, all short cuts overlooked at last stage of the build [not sure if I can mention builders name on here so I wont, that is so I do not over step rules [ in fact it is just typical of the whole damn build, it was fraught with problems some of them really major ones]



For this message the author alladinsane has received gratitude : ad2002
Top
 Profile  
Reply with quote  
 Post subject: Re: MCB not working..
PostPosted: Wed Feb 08, 2017 6:26 pm 
Offline
Approved Electrician

Joined: Sun Apr 24, 2011 7:01 pm
Posts: 2417
Location: South Yorkshire
Has thanked: 147 times
Been thanked: 520 times
alladinsane wrote:

Thank you , Do you think I should put the outside socket on its own mcb, as it seems there are plenty of available places[ways] left for the inserts, would need to obtain an mcb, though that should not be a problem, but what size please ?


Indeed put the outside socket on it's own MCB. You have the space and Hager MCBs are cheap enough. I would suggest a 20A MCB.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next


Similar topics
   

Time zone: Europe/London


Who is online

Users browsing this forum: PETER R and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  


 

 

 

News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list
ultimatehandyman privacy policy

Contact

 

Powered by phpBB® Forum Software © phpBB Group

phpBB SEO