Maximum demand calculation

[yarcyk]

Hi.

Question regarding maximum demand calculation.

I have a customer which wants to have a second kitchen fitted in the house. Is this at all possible?
There are two consumer units in the house.
One which has following circuits:
oven 40A
hob 32A
ring basement 32A
ring gtound floor 32A
ring 1st floor 32A
ring 2nd floor 32A
ring 3rd floor 32A
ring outside 32A
water heater 16A

other board:
lights basement 6A
lights ground floor 6A
lights 1st floor 6A
lights 2nd floor 6A
lights 3rd floor 6A
outside lights 6A
doorbell 6A


Electric water heater is only a back up as gas boiler is normally used.
As it sounds like a big house it really isn't. There is only one big room on each floor, and one kitchen in the basement.
It looks like there is 4-5 sockets on each floor, 2-3 lampholders on each lighting circuit.
Cut out fuse is 100A.
Based on mcb ratings it would not be possible, but if you count every single power point and check what is likely to be used for I think it might be possible.
Also, can calculations be made based on current use of the house ( one lady lives in the house on her own). Unlikely that both kitchens would be used at once. (2 double ovens, 2 hobs)

And to make the thing worse she wants induction hob in her new kitchen.

How would you make calculations and use diversity to see if there is a chance of putting new kitchen in.

I am really interested in fitting new kitchen for her , but as I am now preparing myself to be part P registered I would like to know how you would approach the problem.

 

[telectrix]

bet if you turned everything you can think of and clamped a tail, you'd get nowhere near 100A. just get on with it.

 

[GMES]

^^^^^As above

 

[ferg]

This kind of calculation mostly comes down to experience.

Tel has bags of it and will be right.

If in doubt do as he suggested turn everything on and clamp a tail.

You then have to consider the chances of both kitchens being at maximum load at the same time.

 

[telectrix]

for example. in your OP, you have oven 40A, hob 32A. that's 72A. both together, you'd be hard pushed to see more than 22A with them both full on.

 

[yarcyk]

I know it wouldn't be a problem, just to have it all right. As this is listed building there will be architect and Buiding Control inspector involved, so in case there are any questions asked how to convince him?

Also for the purpose of certification some calculations should be done? Who is really to be pleased with results? Building inspector?

Using a clamp on the tail would be a method?

 

[ferg]

The person to be pleased is the person undertaking the work.

The buck stops with them.

 

[Knobhead]

What do colleges teach these days?

 

[davesparks]

What do colleges teach these days?

Health and safety, literacy, numeracy, basic computers, health and safety, how to wire a few things on a wooden wall, health and safety, risk assessments, method statements.
And if there is time a little bit about electricity.

(This is only my experience of the modern apprenticeship, others may have escaped any mention if electricity)

 

[davesparks]

To answer the OP,
You could calculate the maximum demand based on the diversity tables combined with some common sense.
But since you have it all there already you could just carry out a load study to get exact figures.

 

[Octopus]

I know it wouldn't be a problem, just to have it all right. As this is listed building there will be architect and Buiding Control inspector involved, so in case there are any questions asked how to convince him?

Also for the purpose of certification some calculations should be done? Who is really to be pleased with results? Building inspector?

Using a clamp on the tail would be a method?

Hum..... listed building, adding a "2nd kitchen".... alarms bells.

Is the intention to have 2 seperate dwellings? - if so you should be looking at a rewire to ensure that the circuits are completely seperate between them....

Need far more information...

 

[Lucien Nunes]

Based on mcb ratings it would not be possible

Based on MCB ratings it's a b****y loud doorbell!

 

[shanky887614]

Based on MCB ratings it's a b****y loud doorbell!

lol, there was a guy that modded his radio to use a air horn.

pulled around 6amp i believe lol

 

[yarcyk]

There is no intention to have 2 separate dwellings. I would not be possible.
It would be just more convenient location for new kitchen that is is now. However the original kitchen remains in place so it might be used every now and then.

 

[Knobhead]

I’ve just looked though your previous started threads.

Go back to college. You’ve a lot to learn.