Kva for 12 flats

[ejmoore]

Morning everyone

ive been asked to calculate the maximum demand for a conversion of commercial property to 12 one bed self containted flats. There will be no gas service available. Each flat will consist of a 32 amp socket, 45 amp shower, 32 amp cooker, 20 amp electric radiators, 16 amp water heater and 6 amp lights. 1 landlord supply, loading not yet known.

After applying diversity of all loads x 0.4 60.4 amps per flat, this dosnt seem enough for all electric install, should I use onsite guides allowances.


60.4 x 13 = 785.2 x 230= 180.569 W to convert the watts to Kva is the calculation 180,000/ 1000 = 180Kva.

Are my calculations correct, or am I dumber than I think. Lol

 

[markythesparky]

that's about 62.5 amps per flat. your cooker and shower alone exceed that!

 

[ejmoore]

that's about 62.5 amps per flat. your cooker and shower alone exceed that!

Totally agree, I would think 125 amp by using onsite guides allowances.

My knowledge isn't to great on Totalling Kva, I've turned the job down anyhow. I priced up for a electrical engineer to design, calculate and plan the infasturture. The client dosnt think this is needed. My knowledge is limited to single phase domestic installs. Getting ahead of my abilities I think.

Thanks for your reply.

 

[chrish_1977]

Always a pain to turn down work, but at least you realised your limits before commiting to the job, I think the way you had priced would be best as it may have cost you more if you get your calculations wrong.

 

[Clive P]

Hi,

Totally agree with Chrish, As E54 and Tony pointed out in another thread , correct diversity is not for the faint hearted; and if you get it wrong on a block of 12 flats your'e definitely in the poo. In this circumstance I think you gave the customer the best advice, that is , have the calcs done by a Professional Engineer.

Regards.