I have just noticed this change requiring the maximum demand to be stated on the new EICR template. Is this possibly a copy and paste mistake or is there a rationale behind it?
I have just noticed this change requiring the maximum demand to be stated on the new EICR template. Is this possibly a copy and paste mistake or is there a rationale behind it?
The other way of tackling this problem is to use actual maximum demand data for the installation - get the customer to obtain their half-hourly import metering data from their supplier, then you can use that to determine the actual highest average demand over a half-hour period, which might be a reasonable representation of the demand in thermal terms.
Potential weakness of that approach is it doesn't tell you the maximum instantaneous demand, or MD over shorter periods, or what the maximum demand might be under a different occupier (more people in household, different habits/routines affecting diversity etc).
But at least it is based on real, accurate data - settlement metering is accurate to within a couple of percent. Only fly-in-the-ointment is where there's solar/battery installed which then needs some more difficult analysis adjusting for solar/battery energy flows.
I'm surprised there's not a more formal, defined process for how Maximum Demand should be determined because with it being inherently probabilistic, rather than purely deterministic, it opens up the space for significant differences in how different people might determine the value, the electrical equivalent of 'how long is a piece of string?'.
The other way of tackling this problem is to use actual maximum demand data for the installation - get the customer to obtain their half-hourly import metering data from their supplier, then you can use that to determine the actual highest average demand over a half-hour period, which might be a reasonable representation of the demand in thermal terms.
Interesting idea, but would that not require a smart meter?
Moreover, presumably, it is the electrician's job to get the info.
I'm surprised there's not a more formal, defined process for how Maximum Demand should be determined
In which case, the term is pretty meaningless.
30A per 1000ft² (or 32A per 100m²)
what the maximum demand might be under a different occupier
That formula puts us well beyond the rating of the DNO's fuse, but there are only two of us, so most rooms are unused most of the time.
Of course that could change markedly when we sell/leave feet-first.
The other way of tackling this problem is to use actual maximum demand data for the installation - get the customer to obtain their half-hourly import metering data from their supplier, then you can use that to determine the actual highest average demand over a half-hour period, which might be a reasonable representation of the demand in thermal terms.
Interesting idea, but would that not require a smart meter?
Moreover, presumably, it is the electrician's job to get the info.
I'm surprised there's not a more formal, defined process for how Maximum Demand should be determined
In which case, the term is pretty meaningless.
30A per 1000ft² (or 32A per 100m²)
what the maximum demand might be under a different occupier
That formula puts us well beyond the rating of the DNO's fuse, but there are only two of us, so most rooms are unused most of the time.
Of course that could change markedly when we sell/leave feet-first.
Interesting idea, but would that not require a smart meter?
Moreover, presumably, it is the electrician's job to get the info.
Yes but most homes already have smart meters and ultimately all homes will have them, so I don't see that as a problem in the longer term.
I don't know what it's like with all suppliers, but some already have a function for the customer to download their half-hourly data, so it's a simple job to then just find the maximum value, or rank them to find the top X half-hour periods.
Either way, now that smart metering is available and half-hourly data from them is increasingly available, it seems only logical that the Wiring Regulations ought to reflect this to make more accurate, data-driven assessments of MD,
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