Help! Wiring for 4.3Kw cooker

[candidcamel]

Is this part of the regulation, or just best practice?
...I may have to go to court based on this....

 

[IQ Electrical]

Is this part of the regulation, or just best practice?
...I may have to go to court based on this....

You'll struggle in court on issues of good practice.
Have you paid anything yet for this work?

This is my patch, I'm interested in the outcome!

 

[telectrix]

522.8.1, and 522.8.11 (sharp edges)

 

[IQ Electrical]

522.8.1, and 522.8.11 (sharp edges)

Oh I agree with those reg's but I still wouldn't bring it up in a court. Grommets are only doing a job during installation, once the walls are plastered, you have an insulated and sheathed cable held in place.

Unless there is visible sheath damage, would you code a missing grommet on a PIR?

 

[telectrix]

see your point, but the number of times i've seen the plaster disintegrate, the cable pressed back against the entry hole by plaster....... and what if it's dry lined? the cable is usually loose behind the board

 

[ridemx27]

i cant see that standing up in court tbh bs7671 regs are non-statutory, if he wasn,t registered you would stand a good chance and if the jobs not finished who was to say he didnt intend to fit them ? i really wish it was that easy to stop cowboys doin bad work, but what do these proven idiots on rogue traders etc get ? nothing they seem to walk clean all the time hence y we now have to fight to get work and settle for a wage you could match workin in tescos with no qualifications!

 

[chiefengineer]

i assume cooker is on own circuit as they say over 3kw , should be .

4300w/230v= 18.6A , should be ok .

2.5mm t&e cable can take 27A clipped direct.. if has going through walls and ambient is high could be different.....

Not quite correct. Okay if you have a bit of leeway but you have to take into account the PF. The power factor of a system affects the cable size as this dictates the Kvars wasted in effectively heating wires for no useful work. A generating system will run at somewhere between .4PF and 0.85PF depending on how well it is manufactured, the given load and the actual demand on it. If we take a good PF of 0.8 then even with this PF which in a domestic situation would be hard to achieve, the actual amperage load on a 4.3KW system would be around 22A, not 18.7. That's why you have to use cable for a load that you do not see - Kvars provide no work but heat wire and the wire size must be sized accordingly. Of course if you aren't going to get to 4.3Kw then no big deal.

 

[IQ Electrical]

I'm quite sure the OP will have power factor correction installed in this situation.

Power factor is not normally part of domestic design, indeed my own power factor, measured with a Fluke 435 was as close to unity as I've ever seen.