SWA questions, doubting electrician

[LeeH38]

Recently had an electrician in to wire up power to a detached garage and also wire in a 32 amp rotary switch for an eventual hot tub install.

He has used a spare 40amp MCB in the house consumer for the garage and a 32amp one for the hot tub point. Cable run for both is about 10m each.

He left on Friday and the whole side of the consumer in the house tripped immediately and I started having doubts about other things then as part of the kitchen is also on that side of the consumer and hasn’t been touched. I then switched the two new circuits off and the consumer continues to trip whenever I plug anything in in the kitchen. Been promised a visit to sort it out but today I simply removed the new wiring into the consumer to see if I could get the kitchen back up as it’s a nightmare without and everything has returned to normal.

Now having major doubts about the rest of the work and have had another opinion from a retired electrician neighbour and it doesn’t look good. However original installer is saying it’s something simple and everything has been done to standard.

My main doubts are:

1. Is 4mm armoured cable sufficient for this layout. I have a 32 and 6 amp MCB on another board in the garage run from the 40amp MCB on the house board. This is to run 8 sockets and 4 led lights.
2. Is 4mm armoured cable sufficient for a hot tub. I am led to believe it should be 6mm.
3. Non of the armour part of the cable is earthed, he reckons it’s fine as it’s 3 core and earth is inside. I don’t believe this though and think it needs earthing at the house consumer at the very least.

I am struggling to have a reasoned discussion as he is the electrician and I’m reading stuff on the internet, I wouldn’t have even started searching had I not had the initial issues.

Meant to be inspected and a certificate off someone else this week but not sure that means much tbh?

Any advice on how to approach this very much appreciated.

Thanks,

Lee

 

[Strima]

The tripping could be purely coincidental but without a proper inspection and test we cannot diagnose over the internet.

As for the SWA earthing, the armour should be earthed at the supply end as abare minimum.

How is the SWA installed? If buried or clipped to to a wall then it is not sufficient for the 40 amp OCPD you have mentioned.

 

[westward10]

Any chance of some pics.

 

[LeeH38]

It’s clipped to a wall.
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Of which parts? Will grab some when it’s light if it’s outdoor you need. Cable run is clipped to wall, clipped under steps and a small part runs along the edge of the garden next to the garage base.
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Had this reply when I have questioned the cable thickness too.

For a 24m cable run the max load for a 4mm is 43.5amp its on a 40amp and 13 metres and a 32 amp for the hotub is nowhere near the max demand either

 

[westward10]

A three-core 4mm cable when clipped direct is rated at less than 40A.
Some internal pics at the fuse boards would be good.

 

[SJD]

The tripping you describe sounds like a N to E short on one of these new circuits. If that is the case it should have been found by testing before anything was energised; disconnecting the new cabling will have removed the N to E short.

 

[Andy-1960]

Did he just install a supply cable to a garage that was already wired or did he wire the garage as well?

 

[LeeH38]

Top one is before I disconnected (obviously).
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Did he just install a supply cable to a garage that was already wired or did he wire the garage as well?

Both.

 

[Andy78]

1. No the 4mm armoured cable is rated at 38A clipped direct, the 40A breaker is wrongly selected for the cable size. The claim of 43.5A is incorrect and suspicious as the regulations give cable current carrying capacities in whole numbers.

2. Yes 4mm may be fine for a 32A hot tub supply volt drop permitting, I have seen it where hot tub manufacturers insist on 6mm in their instructions though.

3. Yes the armouring should be earthed as it is an exposed conductive part. If the cable is buried at all then it should be earthed for that purpose too.

 

[westward10]

Can you show below the board where the cables enter.

 

[LeeH38]

Cables just fed through bottom of unit, no earthing.

 

[Andy-1960]

Has he given you any test paperwork? Also this is notifiable work under the Part P scheme, so he should have submitted this to the local council. I agree with SJD it sounds like a neutral earth fault, this should have been picked up if he had tested his work as he should have.

 

[westward10]

What's the board in the garage like.

 

[LeeH38]

What's the board in the garage like.

I’d take some pics but my lights don’t work ? cable is fed into consumer through a rubber/plastic gland and again no earth.

 

[Pretty Mouth]

4mm 90deg SWA would be okay at 40A wouldn't it?

https://www.whyprysmian.co.uk/BS5467.pdf

 

[SJD]

I’d take some pics but my lights don’t work ? cable is fed into consumer through a rubber/plastic gland and again no earth.

As mentioned earlier, the armour has to be earthed at least at one end.

So if someone damages the cable, and shorts L to the armour, it does not make the whole armour live. Which could prove fatal e.g. a buried cable that someone digs into with a metal spade etc.

This is nothing to do with the fact that there are 3 cores, and one is used for the E.

 

[westward10]

4mm 90deg SWA would be okay at 40A wouldn't it?

https://www.whyprysmian.co.uk/BS5467.pdf

Unless the terminals the conductors are terminated at are rated at 90°C then you use Table 4D4A.

 

[telectrix]

the steel armour of the SWA must be earthed, even if only at the supply end, when a 3rd core is used as cpc (earth).

 

[LeeH38]

Well everyone has confirmed what I suspected. Not sure where I head now apart from starting again with someone else. I know someone who can probably correct it but the whole point of using an electrician was for it to be signed off.

 

[westward10]

You say in #1 someone else is signing it off?

 

[LeeH38]

You say in #1 someone else is signing it off?

Yeah someone linked to the first person. Wouldn’t want to get it signed off and the start changing stuff although it looks like the sign off isn’t worth a great deal from some people.

 

[westward10]

It is a bit worrying they feel the armour doesn't need earthing because to a competent electrician this is a fundamental requirement.

 

[snowhead]

The person "Signing it off" should identify the issues, to which the installer will have to return and fix, followed by a revisit from the "Signing it off" person, who may or may not also be the Notifier.

You may as well cancel the original, pay him off and get someone else who can complete, sign off and notify.

Where are you located, someone here may be able to sort it.?

 

[LeeH38]

It is a bit worrying they feel the armour doesn't need earthing because to a competent electrician this is a fundamental requirement.

Totally agree with you. Looks like I’ve been had again then.

The person "Signing it off" should identify the issues, to which the installer will have to return and fix, followed by a revisit from the "Signing it off" person, who may or may not also be the Notifier.

You may as well cancel the original, pay him off and get someone else who can complete, sign off and notify.

Where are you located, someone here may be able to sort it.?

I’m beginning to think it would be signed off regardless. I have currently paid just over half but not sure I should pay the rest and then pay someone else to put it all right, surely I should use the retained money (and no doubt add to it) to get it done correctly.

I’m in the Manchester area.

 

[telectrix]

Totally agree with you. Looks like I’ve been had again then.


I’m beginning to think it would be signed off regardless. I have currently paid just over half but not sure I should pay the rest and then pay someone else to put it all right, surely I should use the retained money (and no doubt add to it) to get it done correctly.

I’m in the Manchester area.

you should give the original sparks the opportunity to rectify it. as it stands, you're on a winner as you have only paid half. talk to him, tell him your concerns. if necessary show him the posts on this thread. if he fixes it and gets it signed off, then pay the balance. if he refuses, don't pay him. you have monies left over to pay someone else. several members in Manc. area should be able to help if needed.

 

[LeeH38]

you should give the original sparks the opportunity to rectify it. as it stands, you're on a winner as you have only paid half. talk to him, tell him your concerns. if necessary show him the posts on this thread. if he fixes it and gets it signed off, then pay the balance. if he refuses, don't pay him. you have monies left over to pay someone else. several members in Manc. area should be able to help if needed.

Gave him a chance and just received a reply saying “will leave you to it as I obviously don’t know what I’m doing” so guessing I need to get someone else to sort it. Next issue is whoever I get next is likely to want to start from scratch rather than deal with someone else’s mess I imagine unless they can inspect the ring main and lighting in the garage and be happy with it.

 

[westward10]

What has made you question the armour of the cable not being earthed because I assume you have limited electrical knowledge.

 

[LeeH38]

What has made you question the armour of the cable not being earthed because I assume you have limited electrical knowledge.

Just that within minutes of him leaving we had a pretty serious problem with the system tripping when we plugged items in the kitchen. Started googling to try and find out what was wrong and then eventually led me noticing other issues with the work.

 

[davesparks]

4mm 90deg SWA would be okay at 40A wouldn't it?

https://www.whyprysmian.co.uk/BS5467.pdf

If it can operate at 90 degrees yes, but it's connected to a normal domestic CU which limits the operating temperature to 70 degrees.

 

[PEG]

Hi,what were the issues,causing the tripping ?

 

[Chivers]

I'd put money on it being the Neutral Earth being terminated the wrong way round causing The RCD to instantly trip if somethings plugged in ?
Given this chap has used what sounds like Stuffing Glands to terminate an SWA instead of the correct Glands maybe he wasn't capable of stripping the Armour properly either.

 

[snowhead]

I bet he forgot which core he'd used as Earth when he got to the other end to connect up.

 

[LeeH38]

Hi,what were the issues,causing the tripping ?

Still no idea, been blocked now on FB/messenger so need to find someone else to fix.

Just left it disconnected in my consumer for now as don’t fancy any other major issues in the house. Might start ripping all the 4mm SWA out in the next few days to make it easier for someone else to do.

 

[freddo]

Oh dear. There seems to be more and more of this type of thread on here, a bit concerning the number of jobs being installed to such a poor standard that even the electrically unskilled clients can see it is wrong. It worries me to think about how many bad jobs are just accepted. It's not even like they tried and made a mistake, the wiring is just chucked in any old way.

I hope you can find someone who cares to do the job correctly.

 

[LeeH38]

Oh dear. There seems to be more and more of this type of thread on here, a bit concerning the number of jobs being installed to such a poor standard that even the electrically unskilled clients can see it is wrong. It worries me to think about how many bad jobs are just accepted. It's not even like they tried and made a mistake, the wiring is just chucked in any old way.

I hope you can find someone who cares to do the job correctly.

The way I see it is due to competition people are quoting quite low in order to secure the work, they then go away and source all the parts as cheap as possible and even decide to underspec certain things as they’ll probably get away with it in order to then maximise their profit. Obviously not all are like this and a lot of people still have morals and pride in their work, it’s sorting these out from the cowboys that is difficult for the customer.

The work goes ahead and the poor customer doesn’t know it’s not right and expects the price is probably ok and if it works is none the wiser. That would have been me had I not had the tripping issue immediately which is concerning to say the least.

The result now is it’s probably going to cost me more than it would have done to get someone competent in the first place, however I am unsure how non knowledgeable people are meant to avoid this in the first place.

 

[Chivers]

Actually I'm looking at those board pictures once more can you look at the other end of the terminated cables and post photos? Can't help thinking that's not SWA and maybe just Hi Tuff or similar

 

[LeeH38]

Actually I'm looking at those board pictures once more can you look at the other end of the terminated cables and post photos? Can't help thinking that's not SWA and maybe just Hi Tuff or similar

This end if I understood correctly?

 

[ferg]

Jeez that's rough.
Nobody is perfect and my own thoughts would have been to give the guy a chance to sort it.

He's blown that opportunity.

Fortunately there are a lot of good tradesmen out there who will do the job properly.

 

[LeeH38]

Jeez that's rough.
Nobody is perfect and my own thoughts would have been to give the guy a chance to sort it.

He's blown that opportunity.

Fortunately there are a lot of good tradesmen out there who will do the job properly.

Issue now is finding someone who might sign it off without starting the whole thing from scratch. What a rubbish situation.

 

[Chivers]

I take it that's under the consumer unit? If so I very much doubt it will reach unless there's an amount of slack to redo this with a correct gland & banjo without either renewing it or a join or isolator of some kind.