New Build Electrical Installation queries

[mstoker1990]

Good Morning Folks

I think I can pretty much answer my own question however some different opinions would be good and if anyone could quote the reg no.s for the answers that would be sound as mine is still boxed up somewhere.

I have just bought a new build property.

Issue Number one.
All Downlighters are fire Rated GU10 with twin and Earth Connected direct with cables stripped further back than the cable clamp....Single insulated cables on show....A Fail Yes?

2
Consumer unit is on a sub main fed via the cheapest looking switch fuse I have ever seen in the meter box with the 16mm twin and earth stripped as it enters the meter box with single insulated cores entering the switch fuse and a taped up earth going to the earth block. a seperate 10mm earth does accompany this.

3
The Smoke Alarms are on the same group RCD that powers Socket outlets, I always believed smoke Alarms should be on there own dedicated circuit or if RCD protection was needed either an RCBO would be needed or it could go on a group RCD not supplying Smoke Alarms.

Let me know your thoughts, the house is built by a well known builder and some of the workmanship from all trades is beyond shocking!!

 

[telectrix]

1 and 2, i agree. bad workmanship. non compliant with BS7671. as for 3. it's common to wire smoke detectors on a lighting circuit. you'll know if the feed is down as the lights won't work.

 

[Plonker 3]

Photos of 1&2 would be helpful.

 

[Octopus]

Not surprised about 1 & 2 - cutting corners and using cheap installation methods will always happen.

3 - absolutely nothing wrong with this - what makes you think otherwise?

 

[ImpededLoop]

1. A bit rough but very common.

2. Very rough.

3. Quite normal and if you get back from a long holiday and the power to the smoke alarms is off, you'll notice as the lights won't be working either.

 

[telectrix]

apprfopriate regs. for 1. and 2. would be 526.5 and 526.8, BS7671 (2011) green book.

 

[tazz]

As for 3. Smoke alarm with battery backup or Grade D, can be feed from RCD on lighting circuit only. Mains only smoke alarms or Grade E, must be on the own circuit with lockable isolation,

 

[mstoker1990]

apprfopriate regs. for 1. and 2. would be 526.5 and 526.8, BS7671 (2011) green book.

Many Thanks for your responses.

I've always been told since the 17th Came in to place that smoke alarms should not be put on the same RCD that supplies socket outlets, Dont know why, I suppose i maybe work to higher standards than those in the new build game.
I always put an RCBO next to the main sw on a board for smoke alarms.

If someone tells me how to put pictures on here I will upload them?

Many Thanks.

 

[Octopus]

Many Thanks for your responses.

I've always been told since the 17th Came in to place that smoke alarms should not be put on the same RCD that supplies socket outlets, Dont know why, I suppose i maybe work to higher standards than those in the new build game.
I always put an RCBO next to the main sw on a board for smoke alarms.

If someone tells me how to put pictures on here I will upload them?

Many Thanks.

I would never do that. It gives the residents the ability to switch them off. Stick them on a ligthing circuit!

 

[telectrix]

Many Thanks for your responses.

I've always been told since the 17th Came in to place that smoke alarms should not be put on the same RCD that supplies socket outlets, Dont know why, I suppose i maybe work to higher standards than those in the new build game.
I always put an RCBO next to the main sw on a board for smoke alarms.

If someone tells me how to put pictures on here I will upload them?

Many Thanks.

get image on desktop. then in reply box, 3rd icon from right "inseret image". select from computer, choose file upload. done.

 

[Engineer54]

How long is this 16mm T&E submain?? Never understood using T&E to supply Houses and flats in a multi dwelling supply set-up. It just smacks of a cheap and nasty install in my book!!

 

[R G]

Also if the T&E is buried anywhere in the walls , would also need RCD protection as well..

 

[TJ Anderson]

Also if the T&E is buried anywhere in the walls , would also need RCD protection as well..

This is very true. I have nearly always done subs in SWA since 17th came along for this very reason.

 

[Plonker 3]

Also if the T&E is buried anywhere in the walls , would also need RCD protection as well..

No, it needs to comply with 522.6.103

 

[R G]

No, it needs to comply with 522.6.103

True Which states if mechanical protection by earthed metallic conduit or trunking is not in place and cables are less than 50mm in walls or partitions then RCD protection is required..

BTW its , 522,6,203 in the BYB

 

[mstoker1990]

Still wont let me upload the images, just states which URL to use.

Fully agree, Dont know whether the Twin and Earth runs in the cavity or behind the plasterboard on the backside of the meterbox. If this is the case it wouldnt even be in a safe zone nevermind needing RCD Protection.

The Twin and Earth Probably runs about 6-7Metres

 

[telectrix]

i had that problem some time ago. would only allow pics from url, and not from computer. could be a browser problem. pm marvo or sintra.to see if it can be sorted

 

[Deleted member 26818]

To be a pedant, the requirement to provide additional protection for cables concealed in walls, allows for:
Installing at a depth greater than 50mm.
Earthed metallic sheathing.
Earthed conduit or trunking.
Mechanical protection sufficient to prevent penetration by screws or nails.
By running cables in prescribed zones and providing 30mA RCD protection.

Always seemed odd to me that only the last option requires the cables to be run in prescribed zones.

 

[davesparks]

To be a pedant, the requirement to provide additional protection for cables concealed in walls, allows for:
Installing at a depth greater than 50mm.
Earthed metallic sheathing.
Earthed conduit or trunking.
Mechanical protection sufficient to prevent penetration by screws or nails.
By running cables in prescribed zones and providing 30mA RCD protection.

Always seemed odd to me that only the last option requires the cables to be run in prescribed zones.

It's not that odd when you look at the history of it, the bit about RCDs was pretty much just added on to the end of the existing regulation. The bit about the safe zones was always there, it's just adding the RCD that was new.

 

[The Electrician]

Please can we see some photos?
From what you have described:

1 and 2 yes, that sounds absolutely disgusting that someone has done work like that. It pains me that people are being allowed to work as an electrician without being competant and fully trained during a proper apprenticeship. Electrical work is for professional people, not monkeys who don't care or understand what they are doing. My opinion is that the individuals who did this work should be traced and banned from electrical work/prosecuted and fined.

As for 3, it is standard procedure to put smoke alarms of the lighting circuit - one of the reasons is, as another poster said, if the lights are not working you know the feed is off. I do wish there were National/International standards of practice for electrical installation.