2396 Ep 5 - Maximum Demand & Diversity, Part 1 Understanding Demand

This video covers the understanding of demand, when considering maximum demand and diversity.
Understanding maximum demand and applying diversity is an important part of the 2396 design course.

[@loosecannon5813]

I went to an empty house out in the sticks recently, no gas to the property so the 'plumber' had managed to convince the landlord to have TWO electric boilers fitted, one for hot water the other for rads, this along with the electric oven/hob and every mod con in the kitchen, and you can see where I'm going with this.... unfortunately the boilers 'pulled' 94 Amps when they were on together!

[@Japanese_one_Tokyo]

Excellent. Subscribed

[@alvinashman6371]

You're probably better off just leaving the box blank as no two electricians will ever conclude the same maximum demand for an installation. You're estimating the peak current demand of an installation and recording it on an EIC or EICR... The only thing that should be estimated on either of these, is the age of the installation.

[@SparkyNinja]

Why wouldn't they? If they ask the correct questions of the installation then they should come to nearly the same outcome. If they don't then they need to develop this.

[@alvinashman6371]

You're assuming every electrician will apply the same diversity and allowance to calculate maximum demand. There's a method for this in the OSG but not every electrician chooses for following this guide. I've read all sorts of methods for calculating maximum demand from adding up all the overcurrent protection ratings and dividing by 40% to just writing down whatever the supply overcurrent protective rating is.

[@stevekeys262]

Alvin Ashman you mean subtracting 40 per cent, not dividing.

[@Михаиллеви]

@@stevekeys262 actually it is multiply by 0.4 to get 40 per cent of the total amperage of the breakers. Neither this method nor just sticking down the total main fuse size appears to be authorised anywhere. However i am not saying they are the wrong way to proceed but certainly expedient

[@normanboyes4983]

That was very well done 👍

[@McOchanIKut]

Could you please do a video on diversity and maximum demand for a domestic installation with a three phase supply but with both three phase and single phase loads? I have done designs of such developments with pumps eg water pumps with three phase motors and have had the challenge of applying diversity for the three phase and single phase circuits. The classification of loads can also be challenging e.g the oven connected to the ring circuit, is it a cooking device? Could we have a tutorial with all the Kitchen equipment and pumps in a dwelling?