Once you apply enough fiddle factors, it becomes no better than reading the rating on the supply fuse and multiplying by 230.

I can see load shedding becoming more important in the future.  My new EV charger came with a current clamp for the meter tails.  If I start using too much power inside the house, the EV charger will tell the car to slow down its charging.

Hi Simon,

who would use the fuse rating and multiply by 230 ? 60A fuse (60x230=1,380) ? are you saying to use this as MD?

can you elaborate more on the fiddle factors? the formulas are being proved against real world data logger  load current profile recordings for MD, so any formula variations have been rationalised and justified based on factual field trial data. which the to modes are out performing the IET and National grids MDAD calculation modes.

Yes, load shedding is good, but load shedding tech cant be used for customers who want ASHP and over predicting MD does lead to upgrade cost for the installation, these calculations based on their accuracy levels, show that in a lot of cases the MD is a lot lower than originally assumed and can remove the financial burden of supply upgrades and take away the choke on a lot of schemes and projects.

Hi Simon,

who would use the fuse rating and multiply by 230 ? 60A fuse (60x230=1,380) ? are you saying to use this as MD?

can you elaborate more on the fiddle factors? the formulas are being proved against real world data logger  load current profile recordings for MD, so any formula variations have been rationalised and justified based on factual field trial data. which the to modes are out performing the IET and National grids MDAD calculation modes.

Yes, load shedding is good, but load shedding tech cant be used for customers who want ASHP and over predicting MD does lead to upgrade cost for the installation, these calculations based on their accuracy levels, show that in a lot of cases the MD is a lot lower than originally assumed and can remove the financial burden of supply upgrades and take away the choke on a lot of schemes and projects.

(Pedantic note: that should be 60x230-13,800)

My response was somewhat tongue-in-cheek. 

I'm assuming that you already have the supply, have already ordered the supply, or are looking at a price list for a new supply and picking the highest you can afford.

Many years ago, I heard of a "constant" called Finagle's Finagling Factor.  Oddly, I can't find any reference to it on Google.  Suppose you're doing a calculation, and you know what answer you're expecting.  But the answer you get doesn't match the one you expected.  It's clear you need to apply a correction factor.

If the answer you want is X, and you got the answer Y, then the correction factor must be X/Y.  Because that way, the answer comes out as Y * X/Y = X.  Problem solved.

We know that an average sized house with non-electric heating will run happily on a 60A fuse.  If your load estimate comes to 150A, then it's probably wrong.  So keep coming up with "correction factors" to apply to your estimate until you converge on Finagle's Finagling Factor.  In this example, it's 0.4.

That's probably not going to work so well for an ASHP on a 60A supply.  But given that heat pumps are all computerised these days, I don't see why you can't tell one to turn off for a few minutes while somebody has a shower.

Hi Simon,

okay I now get your view point no issues.

so the calculation formulas are fixed, in that we don't keep tweaking to get a favourable result.

from our live logging sessions the results have shown MD to be a lot lower, even with and EV charger, air source heat pump, 4 plus person living etc the MD isn't as high as you assume, and the two modes of new calculation do a great job in a true reflection of installation MD at the point of connection to the DNO.

My aim for these two calculation methods is to give industry a solution which is not only quicker and simpler to perform but also significantly more accurate, and this will be then back up by real world data (Empirical Validation/Modelling Process), by monitoring property's under test for two weeks with a Fluke power quality analyser (the master data sets and backing tables to this report the raw data will be made available to institutions like the IET or academia for review and scrutiny them self's).

I do like your idea around load shedding being added to the ASHP, think were long away from such power management systems being utilised within property's, but also as we are proving with factual data in a lot of cases the MD is lower than previously assumed so there isn't a need to restrict the property's usage at given time, this wont be the case for all but a lot of stand household will truly benefit from this.

I have seen this firm hand at a country level scale of how many people wanting to go green but they cant or flocking out of pocket needlessly because some electrician used an out dated mode of MD calculation!

the estimation method works best for electricians who have first hand knowledge of the number of site DB's and the specific final circuits info. the occupancy method works best for DNO's and network planners