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Here is a questionnaire I got handed from a sparky I know. I have no idea where he got it but interesting to see how much everyone differs, I know I did!

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You attend at a house partially constructed, the previous electrician left and it is now over to you to finish the work.

Upon inspection of the existing work all looks in order but you have a few potential problems. It is undertaken to the 16th regulations and during your inspection you find:

(please answer what you would do, if anything)

1. The kitchen has a split hob and oven, the hob is gas and requires a spark supply, what would you use to power this, it sits alone at a good 8 feet from the oven and it is not possible to connect to the oven supply, it is surrounded with sockets on a kitchen and utility ring main. RCD protected at the board and on a 32a MCB. Where would you supply this from and what fittings would you use.

2. During your inspection you have a look at the oven to see how possible it is to wire the hob from here, upon opening the 20a double pole isolation switch to the oven you find it is only 2.5 mm twin and earth. This comes from a 16a MCB in the DB. The client states the ovens power is only 2.5kW in your opinion would this be acceptable?

3. Presuming you are satisfied with the supply at question 2 you go to look at the oven and find the your client is incorrect. It is actually a 4.6kW double oven. Would this supply still be suitable?

4. Also in the kitchen, you discover a 1 gang socket under the sink, this is to power a dish washer sat next to the sink. The socket is within the sink cupboard and forms part of the RCD ring mains from a 32a MCB, would you be happy with this.

5. Whilst inspecting the DB, you find that the supply to the garage is from a 16a MCB and is RCD protected. The cable supplying this is 2.5mm Twin and Earth. The cable run is 30 feet. Within the garage is a small 2 way DB with a further RCD protection. This is supplying 1 x socket outlet, 1 x light fitting and 2 x 300w garage door motors. Would you be happy to leave this as it stands?

 

Flying Scotsman

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Here is a questionnaire I got handed from a sparky I know. I have no idea where he got it but interesting to see how much everyone differs, I know I did!------------

You attend at a house partially constructed, the previous electrician left and it is now over to you to finish the work.

Upon inspection of the existing work all looks in order but you have a few potential problems. It is undertaken to the 16th regulations and during your inspection you find:

(please answer what you would do, if anything)

1. The kitchen has a split hob and oven, the hob is gas and requires a spark supply, what would you use to power this, it sits alone at a good 8 feet from the oven and it is not possible to connect to the oven supply, it is surrounded with sockets on a kitchen and utility ring main. RCD protected at the board and on a 32a MCB. Where would you supply this from and what fittings would you use. The nearest socket to the location of the hob would have a switched fused spur taken from ring main, dropped down to a single socjet from switched side of spur.

2. During your inspection you have a look at the oven to see how possible it is to wire the hob from here, upon opening the 20a double pole isolation switch to the oven you find it is only 2.5 mm twin and earth. This comes from a 16a MCB in the DB. The client states the ovens power is only 2.5kW in your opinion would this be acceptable? Working the calculation out comes up with the current rating of just over 10 amps, so 16 amp on a 2.5mm supply seems acceptable to me and i would use that supply for that size oven.

3. Presuming you are satisfied with the supply at question 2 you go to look at the oven and find the your client is incorrect. It is actually a 4.6kW double oven. Would this supply still be suitable? Again working that calculation out comes up with a current rating of 19.6 amps so if the mcb is upgraded to 20 amps which is the maximum rating a 2.5mm cable can take, (24amps for the max current rating of 2.5 ) then again i would reuse it but i would have put 4mm in instead when i first put the supply in.

4. Also in the kitchen, you discover a 1 gang socket under the sink, this is to power a dish washer sat next to the sink. The socket is within the sink cupboard and forms part of the RCD ring mains from a 32a MCB, would you be happy with this. I would be happy IF it was protected by a switched fuse spur for local isolation purposes, If this comes direct of that circuit with no switched spur then that would need altering in my opinion.

5. Whilst inspecting the DB, you find that the supply to the garage is from a 16a MCB and is RCD protected. The cable supplying this is 2.5mm Twin and Earth. The cable run is 30 feet. Within the garage is a small 2 way DB with a further RCD protection. This is supplying 1 x socket outlet, 1 x light fitting and 2 x 300w garage door motors. Would you be happy to leave this as it stands? I would have fed the garage dis board in 2.5mm 20 amp at the first db, then into a 2way db with 1 x 16amp and 1 x 6 amp mcb.
:|

 

sirsparkabit

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I understand the need for local isolation regarding question 4 however as this s/o is rcd protected is it wrong to leave it (legally) as is,i would do the same as you normally but as this is already existing(fitted by other spark) do we have to change it?. :|

 

Flying Scotsman

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I understand the need for local isolation regarding question 4 however as this s/o is rcd protected is it wrong to leave it (legally) as is,i would do the same as you normally but as this is already existing(fitted by other spark) do we have to change it?. :|
no legally i dont think it would need to be changed but it depends what area of the installation youd be testing thus taking on legally, but imho thats what i would do, extend into a spur above the worktop, and then take into ring main from there.

 

DonkeyDong

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There are two resultants replies:

What complies....

And what would you do... (ie I often go above and beyond the requirements of the regs)

D.

 

steptoe

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remember tho,

the regs are only ONE way of complying with the law,

they AREN'T the LAW.

TBH most of the installation could be left as is, with the exception of upgrading the MCBs.

tho, as FS states, wouldnt be the ideal way to wire it in the first place.

 
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Flying Scotsman calculation for the 4.6Kw oven has not taken into consideration any volt drop or other de-ratings that can not be determined from the info we have.

The 16a breaker feeding the garage may be the maximum size as we once again do not know about any derating such as insulation, bunching etc. The connection method of the 2 door motors is not mentioned. I may be tempted to remove the garage c/u Fit a switched spur with a 3a fuse for the light. On the other hand the Garage may be remote from the house and needs to be TT.

 

steptoe

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Flying Scotsman calculation for the 4.6Kw oven has not taken into consideration any volt drop or other de-ratings that can not be determined from the info we have.The 16a breaker feeding the garage may be the maximum size as we once again do not know about any derating such as insulation, bunching etc. The connection method of the 2 door motors is not mentioned. I may be tempted to remove the garage c/u Fit a switched spur with a 3a fuse for the light. On the other hand the Garage may be remote from the house and needs to be TT.
Im wondering if the "questionairre" is a problem in the OPs house?

honesty would produce much more viable answers.

 
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Sorry guys, no it was a question/minor exam a mate had last year spoke to him today and states it was for a job he applied for :)

There is no mention of insulation etc as it was on 16th regs :)

I never did get the answers from him LOL

I think in essence flying scotsman had the nail on the head IMO.

Reading between the lines I presume the garage was incomplete and still remained to be finished? Thats how I read it but all a bit open to question if you ask me? Its the normal story with exam questions I suppose, too many different options :( I suppose the company was trying to see how each candidate would tackle the questions.

Only thing I would do differently is #4? Its in the sink cupboard therefore a switched socket can be fitted IMO there is no need for a sw spur? Thats all I would differ from :)

 
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Im wondering if the "questionairre" is a problem in the OPs house?honesty would produce much more viable answers.
LOL no not my house mate, its needing rewire big time :) So many regs not met, just cant get my lazy ass round to doing it :(

Must call a sparky one day :)

Shed is supplied with a 1.5 SWA from a 32A mcb :( one ring has 28 sockets on it, the other only 7 :(

If there was an exam question with regard to my house it would be a book LOL

 

Mr Sworld

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one ring has 28 sockets on it, the other only 7 :(
My downstairs ring has 20 sockets just behind the TV, the upstairs ring will have much less.

As long as you aren't supplying an area greater than 100m2 then you can fill a wall with sockets from floor to ceiling if you wanted to! :^O

 
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My downstairs ring has 20 sockets just behind the TV, the upstairs ring will have much less.As long as you aren't supplying an area greater than 100m2 then you can fill a wall with sockets from floor to ceiling if you wanted to! :^O
Yes granted mate, would just rather have it 'levelled' out a bit as if there is a need to isolate the 28 I have to reset god knows how many alarm clocks and machines :( The other circuit is supplying only the kitchen an conservatory.

Incidently the ring with 28 includes the shed AND its DB which is 1x 32a MCB with a 1.5 supply. In fact I am going to swap that MCB tomorrow and get my lazy ass in gear.

 

M107

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Here is a questionnaire I got handed from a sparky I know. I have no idea where he got it but interesting to see how much everyone differs, I know I did!------------

You attend at a house partially constructed, the previous electrician left and it is now over to you to finish the work.

Upon inspection of the existing work all looks in order but you have a few potential problems. It is undertaken to the 16th regulations and during your inspection you find:

(please answer what you would do, if anything)

1. The kitchen has a split hob and oven, the hob is gas and requires a spark supply, what would you use to power this, it sits alone at a good 8 feet from the oven and it is not possible to connect to the oven supply, it is surrounded with sockets on a kitchen and utility ring main. RCD protected at the board and on a 32a MCB. Where would you supply this from and what fittings would you use.

switched fuse spur above worksurface to side of hob taken from ring final with flex outlet or socket below hob

2. During your inspection you have a look at the oven to see how possible it is to wire the hob from here, upon opening the 20a double pole isolation switch to the oven you find it is only 2.5 mm twin and earth. This comes from a 16a MCB in the DB. The client states the ovens power is only 2.5kW in your opinion would this be acceptable?

Yes

3. Presuming you are satisfied with the supply at question 2 you go to look at the oven and find the your client is incorrect. It is actually a 4.6kW double oven. Would this supply still be suitable?

yes, but would consider upping the ocpd to 20amp

4. Also in the kitchen, you discover a 1 gang socket under the sink, this is to power a dish washer sat next to the sink. The socket is within the sink cupboard and forms part of the RCD ring mains from a 32a MCB, would you be happy with this.

Yes

5. Whilst inspecting the DB, you find that the supply to the garage is from a 16a MCB and is RCD protected. The cable supplying this is 2.5mm Twin and Earth. The cable run is 30 feet. Within the garage is a small 2 way DB with a further RCD protection. This is supplying 1 x socket outlet, 1 x light fitting and 2 x 300w garage door motors. Would you be happy to leave this as it stands?

To many variables to give a decent answer.

But I'd bin the rcd at supply end, If a remote garage I'd bin the T/E & use swa + up the csa. Consider changing the db for a 4 or 5 way unit.
Having said that it's all academic anyway as I dont take on/sign off 3rd party partly completed works, it's that liability thing you just never know whats hidden away do you.

 
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