I have a 4 zone cooking hob (haven't install yet), the nominal power on it is 6000W

so 6000W/230V = about 25 or 26amp if I calculate right. 

in this case, you need to read the specs of the electric hob, not just the advantage of the hob you are looking at.
Always ask the salesperson questions if you are really keen to get that hob, it will be easier to tell the electrician.

one is 4100 and another one 4500.. two hobs.. one for dry n one for wet

lol, which restaurant uses electric hob? Usually is gas hobs for restaurants and the only electric hobs are those 1 zone portable electric induction hob for steamboat and that alone won't consume that much power.

Its a teka vitroceramic hob with 4 zones.

Induction hobs with 4 zones have connection rating of 7200W/32AMP, apparently induction hobs consume more power than vitroceramic hobs based on comparisons of the W/AMP rate for induction and vitroceramic types and this would be only if u cook on all 4 zones simultaneously like gas hobs. Just read the technical specs and you can do the comparisons.

Ozak:

For teka, http://www.teka.com/products/index/10#!prettyPhoto

choose the induction and vitroceramic hob (1 each) and compare them, the list will come out after you click on compare products.

Look for the maximum connection rating(W) in the electrical connection section. you can see whats the maximum rating for induction, vitroceramic. In the technical specs manual by teka, u need to look for the nominal power (W) listed, not the power rate per zone.

However, I can give another example of vitroceramic and induction hob in another website.

http://www.mayer.sg/index.php/products/hob...ic-641-b-detail  (Induction Hob)
http://www.mayer.sg/index.php/products/hob...c-641-db-detail (Vitroceramic Hob)

The induction hob states overall power of 7200W while the vitroceramic hob states 6600W

Atisha:

I've been using a 2 zone electric hob for a long time and I don't cook everyday, maybe 2-3 times a week and my electricity usage is pretty moderate for 2 pax (The bill never even exceeds 200 per month) If its for a family of 4 or 5 and need to cook 3-4 times a week, then the electricity bill may be about 400-500 per month on rough estimation? Induction hob have higher electrical power rating and the start up is slower than vitroceramic. Also, its safer than using gas because if you have old people living with you and they sometimes forget to turn off the gas, it can be a potential fire hazard in the long run.

BTW i thought induction and vitroceramic hobs fall under electric hob classification?

Ozak: That is including the usage of other electrical appliances. i.e; computer, fan, tv, microwave oven with convection function. I only mention that the electricity bill does not exceed 200 per month for 2 pax usage but never mention the actual bill figure. 

On average, it is about 140-150 per month to be more precise and no change in the figures monthly either with either -/+ few dollars. I need to see how my new electricity bill will be like with my new hob and everything included when my new place is done with renovation.

Weikee:that's new to me. Usually I see energy efficient stickers on fridge,ovens and air cons but i've not really seen one that says an induction or vitroceramic hob is energy efficient unless my eyes have been looking elsewhere in the household appliance dept. 

The efficiency is induction  vs. Hotplate/vitro. They did many test. Electric hob is never energy saving, induction are more efficient when transfer/convert electric to heat.

OMG tarrif rate increase next year  What's next other than the changes to be implemented in 2014?

True vitroceramic is not that energy efficient compared to induction in the varying ways as Ozak has pointed out but however appliances are never truly turned off unless the plug is off itself.

Ultimately, its up to us to conserve electricity on our own properly.

I know what you mean  That's why I agreed with you that vitroceramic is not energy saving in the same ways as induction is, ozak  Just pointing out that conservation of electricity is up to us entirely.

Regardless of the pros & cons of the hob type, it's still a matter of preference, cost factors.

So to weikee and the others, for hobs 6000-7000W range, a 4mm wiring is prefered? I was thinking about the rewiring part as my hob will need 25AMP socket, then the closest would be 30AMP since the other AMP socket would be 20AMP but would it be an overload on the whole electricity load if I pull additional line? Please give advise as I am totally clueless in this?

Ozak, if I'm looking at pieno switches, then do i look out for this?

E82T15D45N
45A 250V Double Pole Switch with Neon + 13A Switched Socket with Neon

Weikee and Ozak, would it be better if I used 6mm than 4mm for 6000W use? I intend to have the main kitchen in the new back extension at my place so there's no wiring at the backyard for now except in the original kitchen space which will be converted into a dining area.

ozak, just to ask, if the back extension wall is already up but yet to do wiring, then does the wiring need to be concealed within the wall?  The electrician has yet to come in because If my understanding goes like this from my dad, the electrician is not from my area.  I'm not usually around to supervise the works so my dad does the supervision daily.

Hi Ozak, please advise how to add another DB box at kitchen? Is it possible? Cost?

Thanks

If the cost not much diff, I would rather choose to hav another DB box at kitchen, no need to hack...