Ground floor lighting trips out mcb

Biggy · Dec 27, 2018

Hi everyone,

My first post but straight in with a couple of issues.

I'll start with a 6amp MCB that keeps tripping out relating to ground floor lights.
For your info:

There is 10 x 3w led recessed lights in Kitchen, 8 x 3w led recessed lights ,plus a main central Led light (approx 100watt equivalent ) in the room next to the kitchen and then the same amount of lights and Main central light in the Back room. I would say the combined wattage including two outside lights (40watt each) will be around 480w so let's call it 500watt on the ground floor.

From my understanding a 60w bulb draws around 0.5amp so in effect 30 of the 60w bulbs (around 1800watt combined ) would require a 15amp breaker which would be comfortable, so based on this theory is the 6amp MCB actually overload on 500watts on Ground floor and this tripping the breaker .

The breaker does not trip immediately as can take 5-10mins sometimes longer, and in some instances it has tripped even when ground floor lights have been OFF.

The joist spaces have all been insulated with rockwool if this makes any difference as I want to eliminate any possibility before I start questioning my electrician who advises that maybe I should fit a 15amp breaker in as he feels 6amp is less power for 30 odd lights .

Can anyone shed LIGHT on this

I'll come to the second issue after I can get a solution to this.

Sorry for the lengthy explanation but I know there's nothing more frustrating than not arming knowledgeable people will full info and expecting solutions. Hope I've not missed anything out.

Hope to get a few responses and guidance as I have basic understanding of electrics.

Thanks

DPG · Dec 31, 2018

This gets murkier and murkier. Are we getting the whole truth?

Harry_P · Dec 31, 2018

DPG said:
This gets murkier and murkier. Are we getting the whole truth?

Well I don't think I've ever been called out to any fault where I have been given the whole truth so.......

Octopus · Dec 31, 2018

Harry_P said:
A simple insulation resistance test will identify exactly what the problem is and also where the problem is.

Not sure I agree with that!

Harry_P · Dec 31, 2018

Murdoch said:
Not sure I agree with that!

Well that's what I would do and it would work for me. What don't you agree with and why?

alasdairp · Dec 31, 2018

Biggy,
Your reply #60 stated:
"Also he tacked in the wires against the wall in a couple places using nails which were then bent over the wires to hold them in place but I did check and they were loose enough just to hold the wires in place so not cutting into any wires."

That alone tells me he was not a suitable electrician. No professional electrician would use bent nails to restrain wiring - proper insulated cable clips and cleats are cheap, easy to fix and every professional electrician carries a suitable selection in their van/vehicle.

I realise why you had a knowledgeable family member come over during the holiday period and see if they could help - and they did. BUT, and a big BUT, they have now changed what the installer did... I would keep very quiet about that, if I were you. It could give the installer a let-out. You needed a professional, qualified and formally approved and insured, electrician to make any judgement. I am retired from day-to-day work and so cannot certify installations - but I work at Government and international levels. I am often asked about wiring issues by friends and family - but never now actually do any practical work (apart from in my own house) - although I could easily and safely do it. It is just not legal to do so. I advise what the problem is and tell them to get a currently qualified and certified electrician to come in and report on what they find and correct it (or quote to correct it).

The law is often not "real justice" in complex situations. I have been there and have several 'bloodied T-shirts' (not real blood!).

Leave well alone. Get in a reputable electrical contractor or a Local Authority designated test-qualified electrician to report on the state of the wiring. The more you fiddle, the deeper your 'hole' becomes. I know it is difficult over the holiday period

I am reading a book at the moment; a knife assult victim was found by an ordinary person. He removed the kni
fe, staunched the blood flow, but it was too late and the victim died. He called the police who found his fingerprints on the knife and the victims's blood on his hands and his clothes. Although innocent, he was immediately the main police suspect for the murder.

Please think about all of this very carefully. It is deadly serious.
Best wishes for 2019
Alasdair

Toneyz · Dec 31, 2018

Harry_P said:
Well that's what I would do and it would work for me. What don't you agree with and why?

The rest of us know what you mean is narrowing down the circuit until you locate the fault to a length of cable etc.

Octopus · Dec 31, 2018

Harry_P said:
Well that's what I would do and it would work for me. What don't you agree with and why?

From the vague and inconsistent information from the OP it "suggests" there is no pattern to if and when the MCB trips ....... so an IR test on the circuit could simply come back as "good"

A water leak could do what he's describing .......

That's all

Harry_P · Dec 31, 2018

Murdoch said:
From the vague and inconsistent information from the OP it "suggests" there is no pattern to if and when the MCB trips ....... so an IR test on the circuit could simply come back as "good"

A water leak could do what he's describing .......

That's all

A water leak would be identified with the IR test if there was moisture between cores the IR test would indicate this
From the information given I am certain the fault would be identified within an hour.
1. Global IR test to identify if it's L/N or N/E or L/E fault

2. Identify which circuit has got the fault that you found in step 1

3. Half split the faulty circuit until you locate the faulty part of the circuit

Should be done in an hour and back in the van and back on the forum

Midwest · Dec 31, 2018

alasdairp said:
.

I am reading a book at the moment; a knife assult victim was found by an ordinary person. He removed the kni
fe, staunched the blood flow, but it was too late and the victim died. He called the police who found his fingerprints on the knife and the victims's blood on his hands and his clothes. Although innocent, he was immediately the main police suspect for the murder.

Please think about all of this very carefully. It is deadly serious.
Best wishes for 2019
Alasdair

Any self respecting competent first aider, knows you don’t remove any foreign object from the body of a injured party, can cause worse bleeding. Instead you make up one of those circular bandages, that you would have handy in your pocket, and place around the wound.

Thought I’d just mention that, ‘case anybody comes across that scenario tonight.

Biggy · Dec 31, 2018

@MurkyD - stop with the nonsense assumptions . If you don't know what your talking about then don't reply to my questions.

I have NOT done the wiring and sparky is NOT my mate, as I said he was recommended from a work colleague who told me he is a qualified electrician its that simple.

I have provided as much info as I can remember, if there's anything missed I will add it if I remember .

@Alisdairp, thanks I'll look into what you mentioned.

My friend who came yesterday I can be confident he if anything made sure the CU breakers are properly and securely aligned and all screws tightened , more than the sparky could have done.
I rang the idiot an hour ago and he said he's round the corner only to find he won't answer his calls again so that makes me more certain than ever he knows he has messed up and doesn't want the headache of having to rip up floor boards if that's what it may take.

I'll just pop over to the tester now and see if he has mysteriously disappeared too.

I am a genuine guy with no need to provide false information to you guys , at the end of the day me, my wife and 5 small children will be moving into the house and the bloody last thing I want is dodgy electrics unsafe for my family.

MarkyD I don't need your input thankyou very much

Biggy · Dec 31, 2018

Should I upload the EIC cert with all readings for you guys to look at , will that help ?

Strima · Dec 31, 2018

Biggy said:
Should I upload the EIC cert with all readings for you guys to look at , will that help ?

That would help, please scrub out/cover any personal information.

Biggy · Dec 31, 2018

Here's the cert docs

View attachment IMG_20181231_165623.jpg

View attachment IMG_20181231_165608.jpg

Markyd · Dec 31, 2018

The man can't even spell cellar

DC-backfrom the past · Dec 31, 2018

ok, an insulation test could come back as a pass.
I had similar recently with a light circuit, the only time it tripped was during the extremely cold weather, the cable contracted and it got tight around the metal on the joists (in the loft). The rest of the time the cable didn't touch the metal and passed the insulation test.

We know electricity is a force of its own at times and sometimes can even seem magical.

good luck finding the fault hope its sorted soon