NICEIC Certification Scheme NICEIC Inspection Thursday, Certificates and Earth Loop Impedence on a TT system

[Kellie Welch]

Hi, I've just registered today after reading alot of the threads yesterday, I have my inspection tomorrow and wanted some advise, they have asked to see previous test inspection sheets, I have some that have been completed by me and then checked and signed off by registered electricians and some that I have created on jobs which are just on copied test sheets, do they need to be on official books bought from NIC or electricial suppliers. Other question is Earth Loop Impedance on TT systems can I use a non RCD protected socket to test it? Have got myself really confused int he last few days and no one to ask. Thanks Kellie

 

[Marx]

Hey Kellie, not sure 'bout your certification and what you're supposed to show them when you don't have the authority to self certify if you're not approved?.....I'm in a similar boat, but am deemed 'competent' by the local government department as my assessment is pending...... on Monday! So I've got a couple to show 'em that I've got together since my assessment date came through.
As for your earth fault loop impedance test on a TT system, you can calculate it for each circuit by adding your earth electrode resistance (Ze) to the (R1+R2) values of each circuit: Zs= Ze+(R1+R2). Permitted values for a TT system can be found on page 50 of your BS7671 book.
Good luck for Thursday!

 

[saveloy]

Hi, I've just registered today after reading alot of the threads yesterday, I have my inspection tomorrow and wanted some advise, they have asked to see previous test inspection sheets, I have some that have been completed by me and then checked and signed off by registered electricians and some that I have created on jobs which are just on copied test sheets, do they need to be on official books bought from NIC or electricial suppliers. Other question is Earth Loop Impedance on TT systems can I use a non RCD protected socket to test it? Have got myself really confused int he last few days and no one to ask. Thanks Kellie

On my assesment I used sheets downloaded from the NIC website. I take it you have jobs that you have done, lined up to show them. They will want to see the certs for these jobs. Certs for jobs you haven't put up for inspection, will not be of interest to the inspector, as he won't be able to check them against the insallation they are relevant to.

On the TT system : Is this a new install. If so I would think that it needs to be RCD protected anyway to comply with 17th edition. Ie any socket outlet rated less than 20A that are for use by ordinary persons and is intended for general use has to have additional protection by means of RCD. This would be regardless of the test you wish to perform.

 

[ajelec10]

Other question is Earth Loop Impedance on TT systems can I use a non RCD protected socket to test it

Why would you have a non rcd protected socket on a TT system? all circuits require rcd protection on a TT system to achive required disconection times.

As for the other question any certificate modeled on the ones in the regs are fine as long as they are filled out correctly.

Just out of intrest kellie could you provide some of your back groud info, ie are you qualified, have you worked in the industry long? etc.

Good luck with the inspection

 

[Kellie Welch]

Thanks for all your answers.

The board is 17th edition 10 way split load dual RCD I have a 20amp socket connected next to the board and this is clearly marked in red with non RCD protected and for testing purposes only, so that I can check the calibration of my meter monthly.

I have added an additional earth rod to the system 4 metres away from the original (last thing I needed last night carpets and floors up!) as the Zs is 3.74ohms but the RCD tripping time is 33.5 s at 1x which is too high. Adding the additional earth rod has not reduced this.

I have two pieces of work to show the inspector, two pieces of minor works lighting and power so he can take his pick which he wants to look at. I have completed minor works forms for both and a complete electrical installation certificate for my own benefit and that of the client.

The second piece is a complete re-wire (my house TT system!) which was checked and signed off by a registered electrician and I have the Part P certificate for this.

Not much more I can do now but hope that he is happy with the quality of my work and my knowledge. In answer to your question ajelec10 I started college in 2005 training as a plumber and electrician, I am level 2 and 3 qualified 17th edition and level 2 inspection and testing but havn't done the part p course, so all these years of hardwork I hope will pay off today.

Good Luck for Monday Mark hope it goes well for you.

Thanks again for the responses.

kellie x

 

[ajelec10]

Kellie you can not have a circuit on a TT that is not RCD protected on mattter how you label it, the ZE on your TT is amazing! bear in mind that the maxium ZE given for a TT system is 21ohms this is the resistance of the suppliers earth electrode not yours so if you got a reading of 25ohms you asume the suppliers electrode is 21 and the resistance of your electrode and the general mass of earth to the suppliers is 4ohms which is good the maxium they say is stable is less than 100ohms.
As for the RCD 1xdelaN you are allowed 300ms
and at 5xdeltaN you are allowed 40ms
So your RCD is perfect!!
Was no need to install another rod in the first place.
Hope this helps
AJ

 

[Kellie Welch]

Thanks for that, had the assessment yesterday was so nervous but the guy was really nice and said at the end that he was nervous as this was his first female electrician. I passed with flying colours and he was not concerned about the rcd tripping over on 1x its 200ms max had to look that one up between the two jobs. He was more concered about the 5x and as that was under 40ms no problem. Said the same that I didn't need the 2nd rod but at least I have back up!

Thanks to everyone for all your help and advise, feel very proud that I am now a fully fledged domestic installer, can hold my head up high at the wholesalers now.
Kellie x

 

[Mark.W]

Well Done Kellie and Good Luck !

 

[kung]

Hey Kellie
WELL DONE !!!!!!!!!!

 

[ajelec10]

Well done
Regards
AJ

 

[Marx]

Congrat's Kellie!....... me too!!......and your talk of 40ms 5x tripping time in one of your posts is given due credit after I reeled it off in answer during grilling!...... so cheers for that!

Best of luck to ya!

 

[wade88]

Hi Guys,

Just been reading through these posts. I am too brand new to the game, but fully qualified. Have yet to book my assessment but looking to do so when i have the money very soon. however, i was unaware, even after conversations on the phone with elecsa and nappit, that i need to show previous certs? i dont quite understand how i am suppose to provide a cert for them to look at when im not "competent" to write them until im signed off? or must i do a job, write a cert up and have someone check it just for proving purposes to the assessor? confuuuuused....Well done tho Kellie! all the best in the future.

 

[IQ Electrical]

If you've been trading and notifying BC along with relevant fees then you will have previous certificates and the assessor will want to see them to check on how they are completed.
If you haven't completed previous jobs then no problem!

 

[brucelee]

congrats kellie and marx