Master RCD switch cutting out - HELP!!!!

[Max Carpenter]

Hi all, New to this Forum, I am not a sparky but am in need of advice because I am on a real real real low budget and seem to be getting one thing after another going wrong at the moment.

Its been happening for a few weeks but only once in a blue moon but the master RCD switch in the CU would flick off and putting it back on everything was fine. Anyway this morning it happened and then again 10 minutes later, then 2 minutes, then instantly as soon as I switch it on its off again. So I switched off all the circuit switches and put the master back on.... ok then tried one circuit and the master went off again, ok so try a different circuit... the same. so I went round the house unplugged everything and reset all the switches to on... this was ok, so tried one appliance and it tripped, tried a different appliance and it tripped again....So I know its not a specific appliance causing this. I left it for about 45 minutes while I had a bath then came down turned the master back on and it was fine, proceeded to energise each circuit ok then each appliance that was critical (such as fridge freezer) and its been on for several hours again now.

I have spoken to my maintenance dept at work and they have given me two little devices, one to test all the sockets (3 lights) and another which they have told me to turn the master switch off remove the front of the CU and then test the Neutral and Earth (it puts volts down the positive) and if it makes a circuit (ie reading on the device) then there is a N-E short and I can diagnosis what circuit its on by testing individual N cables.

I don't know if its of any value but two other things.

1) One of our lights in our kitchen quite often flickers and makes an electrical buzzing sound during this time sometimes goes out completly. It has blown 4 bulbs since March when we moved in

2) I have been told the tail coming into the property is not rated enough and been explained to this is why all your lights dim when you power the shower on for a few seconds because it cant bring in enough power.


Has anyone got any ideas? I will conduct the tests I have been told to do tonight but if anyone else has any suggestions I would greatly appreciate it.

Regards,
Max

 

[Sintra]

Hi & welcome to the forum

I have moved your thread into the DIY electrical section and given you access to reply here.

 

[Max Carpenter]

Thanks.

 

[Octopus]

I'd rather hesitant about suggesting much as you don't, on the face of it, have the necesssary equipment or knowledge to do a proper diagnosis.

On your points:

1. Without looking difficult to say

2. I somewhat doubt the advice you have been given.

May be you should post your location and get someone local in.

 

[Max Carpenter]

I understand, I do have basic knowledge of electricity and the way it works and I wouldn't do anything I wasn't sure about or I think is unsafe I know how dangerous and silly it can be to do things yourself so I will only do what I am comfortable with I just want to try and eliminate some stuff myself as I said due to budget, just moved into our first house, baby on the way and quite a few things gone wrong recently lol always the way. I will try their tests as I am comfortable with what I am doing, We also reckon we know what is might be, there is a shed at this property which is a powered shed, its been done properly with a nice this armored cable its own circuit of the CU in the house and then wired into another CU for the shed. Well we are doing some work and have dismantlement the shed on a temporary basis and I shut of the circuit and wrapped it in tarpaulin and tied together as I was told that would be ok. What my maint dept have told me is if condensation has built up in it it could be shorting despite the circuit being switched off.

Out of curiosity if anyone is near me how much would you charge to come and diag the problem? I am in Seaford, East Sussex sort of half way between Eastbourne and Brighton.

 

[Des 56]

Because you are not an electrician,the maintenance dept who gave you the meter and the instructions ought to be well ashamed of themselves
Taking off the consumer unit cover,exposing live cables and connecting an instrument without sufficient knowdlege is a recipe for disaster

Apologies for being abrupt but,
No way should you receive assistance to do this procedure

You have tried to locate the problem logically using the loads as a pointer,this is a good way for a non electrician to try and locate a problem.be it circuit or appliance,but unfortunately without success,although your method seems sound

You should now either put up with the nuisance tripping,get one of the maint sparks to do you favour and have a look or pay for a spark

Be advised,a fault with an rcd tripping intermittently.it can even be a pain in the neck for a sparks using test gear,for a non electrician without test gear and the ability to use them,it may be a nightmare

 

[Octopus]

You should expect £40-£50 for an hours investigation, but it could take longer.........

Make sure its someone local - there are quite a few in your neck of the woods on this forum.

 

[Jay Sparks]

Hi all, New to this Forum, I am not a sparky but am in need of advice because I am on a real real real low budget and seem to be getting one thing after another going wrong at the moment.

Its been happening for a few weeks but only once in a blue moon but the master RCD switch in the CU would flick off and putting it back on everything was fine. Anyway this morning it happened and then again 10 minutes later, then 2 minutes, then instantly as soon as I switch it on its off again. So I switched off all the circuit switches and put the master back on.... ok then tried one circuit and the master went off again, ok so try a different circuit... the same. so I went round the house unplugged everything and reset all the switches to on... this was ok, so tried one appliance and it tripped, tried a different appliance and it tripped again....So I know its not a specific appliance causing this. I left it for about 45 minutes while I had a bath then came down turned the master back on and it was fine, proceeded to energise each circuit ok then each appliance that was critical (such as fridge freezer) and its been on for several hours again now.

I have spoken to my maintenance dept at work and they have given me two little devices, one to test all the sockets (3 lights) and another which they have told me to turn the master switch off remove the front of the CU and then test the Neutral and Earth (it puts volts down the positive) and if it makes a circuit (ie reading on the device) then there is a N-E short and I can diagnosis what circuit its on by testing individual N cables.

I don't know if its of any value but two other things.

1) One of our lights in our kitchen quite often flickers and makes an electrical buzzing sound during this time sometimes goes out completly. It has blown 4 bulbs since March when we moved in

2) I have been told the tail coming into the property is not rated enough and been explained to this is why all your lights dim when you power the shower on for a few seconds because it cant bring in enough power.


Has anyone got any ideas? I will conduct the tests I have been told to do tonight but if anyone else has any suggestions I would greatly appreciate it.

Regards,
Max

It sounds like you you are going to carry the test out anyway and from the sounds of it, they have given you an instrument to conduct an IR test. This really should be done by a competent person!!!! You need to disconnect any loads, including the ones you don't know about, remove all lamps (bulbs) and neons. If not, you may end up wrecking something, or worse.

I cant really advise you further, so all I will say, is, PLEASE get a qualified electrician in to carry out all the necessary tests and find the fault........you may be on a budget but is it really worth yours or someone else's life???

Jay

 

[nickblake]

Hi max I have to agree with Des , you can spend 5 minuets or 5 days trying to find a fault of a tripping RCD ,it could be anything , the tester with the 3 lights can give false readings and wont help with the problem you have , the light in your kitchen could be the culprit causing an intermittent imbalance , if you think of the RCD as a set of scales balanced , some of the things that could cause the RCD to trip , faulty appliance , moisture in a socket , water in an external light , faulty RCD , low insulation readings, rodent attack, pet peeing on sockets ( especially a cat if its a new home ,happens quite often ) thermal related N to E fault , incorrect wiring in a plug N to the earth terminal etc , these are a few you said you have dismantled a shed even with the circuit switched off if water have go into the consumer unit in the shed this could cause the RCD to trip , it may not show on a continuity test so an insulation test will be required . now this then opens up another point ,you can do a lot of damage with insulation tests so care has to be taken and you need to know what you are doing , I cant really think of any more advise check the obvious kitchen light shed consumer unit if its not obvious then call in a registered spark with the correct test equipment , I hate to be negative but if you make a mistake you could invalidate your insurance , I feel bad I cant advise more

 

[Max Carpenter]

Thanks for all your concern and I understand why I respect electric and I guess I show some level of competence which is why they gave me the equipment. The device they gave me was an Insulation Continuity Tester.

I used the Socket tester firstly around the house and I have found one faulty socket which L and N are wired the wrong way around although I know this wouldn't be causing the RCD to trip. As detailed I tried the continuity test between ground and neutral which returned positive so as described to me that shouldnt happen.

I have also managed to get in touch with an old school friend who is an electrician and describing some things to him he reckons it could possible be the light fitting causing it since its blowing bulbs much more frequently then it should and flickers/makes electrical buzzing.

I did also after taking a look at the outside CU which seemed fine and moisture free energised that circuit that that instantly cut out the main RCD in the inside CU.

So I reckon I have three problems:

A) Incorrectly wired socket
B) Faulty light socket
C) damp insides of the outside CU or sockets.

I will leave the outside CU in the sun tomorrow since its meant to be a hot day to try and dry out. Also going to see if my old friend will pop down to see me although its a long journey for him.

 

[Paul.M]

Max this dose need an electrician to resolve the problem.

Going by your description I think I know the what the fault is but I wont post it up because I know you will have a go yourself and that would be dangerous for a sparky never mind a competent DIYer. No offence intended.

The electrician should be ramp testing the RCD and...................

 

[Octopus]

Thanks for all your concern and I understand why I respect electric and I guess I show some level of competence which is why they gave me the equipment. The device they gave me was an Insulation Continuity Tester.

I used the Socket tester firstly around the house and I have found one faulty socket which L and N are wired the wrong way around although I know this wouldn't be causing the RCD to trip. As detailed I tried the continuity test between ground and neutral which returned positive so as described to me that shouldnt happen.

I have also managed to get in touch with an old school friend who is an electrician and describing some things to him he reckons it could possible be the light fitting causing it since its blowing bulbs much more frequently then it should and flickers/makes electrical buzzing.

I did also after taking a look at the outside CU which seemed fine and moisture free energised that circuit that that instantly cut out the main RCD in the inside CU.

So I reckon I have three problems:

A) Incorrectly wired socket
B) Faulty light socket
C) damp insides of the outside CU or sockets.

I will leave the outside CU in the sun tomorrow since its meant to be a hot day to try and dry out. Also going to see if my old friend will pop down to see me although its a long journey for him.

A. Wouldn't trip a RCD
B. Unlikely to randonly trip a RCD
c. Who knows?

And if the main switch is on obviously you wil get continuity N-E

 

[Max Carpenter]

I know you guys don't know me but I would 100 percent hand on heart not try to repairs just to dangerous and couldn't be confident it was safe that is why i have got in touch with a friend to see if he xan come down. I will admit I will look and even test if I am confident with the procedure but changing / repairing is another story.

 

[Max Carpenter]

also main switch was off when testing for N E leak I know it would be present with main on but was told shouldn't be with main off which is how I tested.

 

[Octopus]

Gentlemen.

Recommend no further advice or guidance to the OP.