Tier 1 and tier 2 prices

[Deleted User]

Can anyone explain to me how a prepay meter, set for no standing charge tariff,selects which units are priced at tier 1, the high rate and tier 2 the low rate. for instance- this is what one occupier had purhased so far this quarter on their meter,-112 units priced at 24p a kwh and 350 units at the 11p a kwh
I suppose this also applys to credit meters,I just wondered what formulae the meters used to collect the yearly standing charge, and in what order it allocates the high and low units

spiro

If you have a ppm that can support T1 & 2 what is does is the number of units per quarter for T1 is divided into a daily number and that is the amount you pay at the higher rate for the day and then it drops to the lower rate. If you dont use enough in a day at the higher rate is 'converts' some of yesterdays cheap rate units to higher rate units to cover the shortfall.

[Deleted User]

Thanks Spiro,perfectly explained.Thats baffled me why the ppm vary so much in T1 and T2 from each other.All good info in prepay tamper detection