NYY Buried Cable - Legit job?

[OsramMyers]

Hi, Ive had a NAPIT qualified electrician out to install a new feed to the garage along with a new consumer unit in there. Its a short distance of around 6m and the cable he used was a 16mm NYY cable, it has been directly buried around 300mm depth with yellow warning tape, It goes under a few paving slabs but mostly its a graveled area.

Is this installation totally 100% in accordance with current building regulations/standards?

When he came to quote I asked for armored cable, he even specced SWA in the written quote but on the day I noticed it was this NYY cable. He said its all OK and he has passed the Part P certificate onto my local authority. When I questioned him after the job he said its easier to use and bend and things have changed over the years and this cable is fine to use in the installation. He said there is no price difference too.

What are people's thughts?

 

[pc1966]

Would NYYJ have the CCC of an armoured cable or a PVC/PVC cable?

Ref A for cable type or ref F?

It would basically have the same rating as SWA, though probably reaching final temp a little faster as no armour to provide thermal inertia.

This NYY-J case is odd because it really comes down to the BS spec saying (these days) you must have earthed armour (or separate duct) if buried so it is not compliant, and the cable (and EU usage) saying it is OK if not likely to be damaged by digging, etc.

 

[OsramMyers]

ANOTHER UPDATE -

Did anyone get on the phone to NAPIT about this and report this thread?

The person I spoke to on the phone called me back yesterday afternoon out of the blue and said he reviewed our conversation on Tuesday with a colleague as it was recorded and wanted to go through what we said.

Basically from saying on Tuesday the depth makes it OK yesterday he just said plain and simple it is NOT compliant and this is why -

"The NYY cable range includes NYY-J and NYY-O cables. These are widely used European power and control cables designed for fixed wiring installation with a voltage rating of 600/1000V. They can be safely deployed in most applications where mechanical stresses are not anticipated – indoors, outdoors, direct burial underground, in concrete, or submerged in water. When NYY cables are required to comply with the UK wiring regulations BS7671 for burial in the ground, they require installation in a conduit or duct to provide protection against mechanical damage. They are not suitable for installation in concrete which is shaken, vibrated or compressed.
NYY-J & NYY-O Cable | Eland Cables - https://www.elandcables.com/cables/nyy-j-pvc-pvc-0-6-1kv-power-cable"

When my NAPIT electrician comes to replace the SWA I will be confronting him about this. I will present this email from NAPIT to the electrician. At the moment I have to assume my electrician is misunderstanding the regulations. If I get any sense that he has put this NYY cable in because he was lazy (I know its more hassle to bend and gland SWA's) and has knowingly signed off this installation as safe and conforming with regualtions I will be putting in a formal complaint to NAPIT.

 

[OsramMyers]

Afternoon all, Napit have just phoned me back, they have thoroughly looked into it, and listened to the recorded call from the OP. After ascertaining the cable type and installation methods from the customer they did infact tell them it was incorrect, however at approx 6 minutes into the call after being told basically the slabs etc all need to come back up to replace it, the OP began asking if it was unsafe or dangerous, which it obviously in real terms isn't, which the tech support told him, and it seems that final part of the conversation was all he then wanted to soak in as it were. This wasn't mentioned to us us full in the posts. They have provided him a follow up call to clarify and given a tech sheet showing that NYYJ is suitable for direct burial, but that's not compliant with BS:7671 unless in a duct as we know.

So overall, seems we didn't get the full picture initially, the installer now knows it's wrong and is rectifying, and Napit have followed it up with the customer too which is good.

Well handled Napit, you shall have another £474 from me next year and a handful of notification fees ?

That is not true.

Then guy on the phone had not heard of an NYY cable I ended up explaining it was basically unarmoured. He then asked how deep it was and what was covering it, 300mm deep 5m distance, mainly gravel, a bit of paving. He said it was fine as its a spade depth. He said my issue was a contractual one.

 

[OsramMyers]

If the reply you got was from Trevor at napit he's a clueless old fool and a danger to be giving advice

Yes it was Trevor I spoke to.

 

[westward10]

ANOTHER UPDATE -

Did anyone get on the phone to NAPIT about this and report this thread?

The person I spoke to on the phone called me back yesterday afternoon out of the blue and said he reviewed our conversation on Tuesday with a colleague as it was recorded and wanted to go through what we said.

Basically from saying on Tuesday the depth makes it OK yesterday he just said plain and simple it is NOT compliant and this is why -

"The NYY cable range includes NYY-J and NYY-O cables. These are widely used European power and control cables designed for fixed wiring installation with a voltage rating of 600/1000V. They can be safely deployed in most applications where mechanical stresses are not anticipated – indoors, outdoors, direct burial underground, in concrete, or submerged in water. When NYY cables are required to comply with the UK wiring regulations BS7671 for burial in the ground, they require installation in a conduit or duct to provide protection against mechanical damage. They are not suitable for installation in concrete which is shaken, vibrated or compressed.
NYY-J & NYY-O Cable | Eland Cables - https://www.elandcables.com/cables/nyy-j-pvc-pvc-0-6-1kv-power-cable"

When my NAPIT electrician comes to replace the SWA I will be confronting him about this. I will present this email from NAPIT to the electrician. At the moment I have to assume my electrician is misunderstanding the regulations. If I get any sense that he has put this NYY cable in because he was lazy (I know its more hassle to bend and gland SWA's) and has knowingly signed off this installation as safe and conforming with regualtions I will be putting in a formal complaint to NAPIT.

Winner, winner.

 

[stevethesparks]

Even if it were ok at a 300mm depth (and I don't agree it is) how does the cable enter and exit the ground, is this part mechanically protected? Also, did the electrician cover the cable with yellow hep tape?

 

[OsramMyers]

Hi, he has been and done the work replacing with SWA. I told him about the BS7671 and what NAPIT said but he just murmerred something about no traffic over the ground.

Just another question. He has not earthed the actual armouring part of the cable. It is a 3 core cable which one is earth. Should the armouring be earthed too?

 

[westward10]

Most definitely it should be earthed. How is it connected either end.

 

[brianmoooore]

The whole point of SWA is that the conductors are totally surrounded by earthed steel wires. Without an earth connection, the wires would just become live if the cable was spiked, and the power wouldn't automatically be disconnected.

 

[DPG]

Hi, he has been and done the work replacing with SWA. I told him about the BS7671 and what NAPIT said but he just murmerred something about no traffic over the ground.

Just another question. He has not earthed the actual armouring part of the cable. It is a 3 core cable which one is earth. Should the armouring be earthed too?

Is this an electrician doing the work?

 

[suffolkspark]

@OsramMyers could you attach a photo of the glands used to terminate the cable? Should be a brass gland with a slide over black shroud on each end

 

[HappyHippyDad]

Looks like he's coming back again.

 

[ipf]

Is this an electrician doing the work?

Napit approved.....with some weird ideas, it seems!

Unless he just likes bringing it on himself.

 

[HappyHippyDad]

There's always a chance he has earthed it. The OP would need to check both ends of the cable and know exactly what they were looking for. In addition, I sometimes bend the banjo inside the plastic junction box, so the little nut and bolt may not even be on view.
Firm evidence needed before the chap is condemned again. Plus, I'm not advising the OP starts undoing electrical items to take a look unless he 100% knows what he's doing and switches all power off first.

 

[suffolkspark]

If the new unit he fitted in the garage is metal, and he's used proper glands it'll be fine, but I'm expecting a photo of a couple of compression glands... lets hope not... OP > no dismantling required