UW and Economy 7 - still worth it?

QrizB

The charger light comes on with the immersion also so I can see when they start drawing power.

If the immersion (the device with the light) is directly switched by the ALCS then this should help you work out the offset, at least.

For example if the schedule is 0000-0700 and the light comes on at 0004 and goes off at 0704, your offset is 4 minutes.

lilac_dawn

https://forums.moneysavingexpert.com/discussion/comment/82120557#Comment_82120557

I'm not going to lie - you lost me a bit there 😂 I am just getting back to this now as need to fix something before the end of the month.

michaels

I have a smart meter rather than ACLS and my smart switches that control night device switch on are all 'in Rejkiavik'

Scot_39

@lilac_dawn

If relying on cheap rate deals - and want to squeeze every last minute out of devices during the off peak using own timers - it's important you know exactly when your tariff changes - summer and winter.

Your supplier might tell you your E7 meter switches / and tariff to off peak say at midnight 00:00 to 0700 GMT (others are available - 0030 0730 GMT etc).

But if your meter has a non zero ALCS randomization offset set (at install time in seconds iirc) - and in your own meters case say, for example it was set to 8 min - it will switch that 8m later.

Both tariff if E7 style twin register based and ALCS restricted power - actually switch at 00:08 to 07:08 GMT.

And of course on your watch / clocks etc in summer time - thats - 01:08 to 08:08 DST.

A mechanical timer normally stays OK - a digital one - might need reprogramming.

So in that case - anything else non ALCS (other heaters etc) should follow your actual switch times - including the 08 min offset.

But the key is for standard use tariff and ALCS load activation the random offset applies to both - so they remain in sync.

[Aside

The fun comes when you then get a modern smart ALCS specific tariff like Snug - billed strictly on half hourly boundaries - can cause issues you need to be aware of - and for self timing.

Firstly their "core" 6 hrs overnight - 0030 to 0630 - and unlike traditional E7 - as I interpret it - its clock time - as they say thats year round times.

And so mechanical timers would need adjusting - and digital maybe not (or maybe - if like I have on one of mine set the ignore GMT/DST switch setting).

And when it comes to your alcs restricted power would potentially still switch 8m late. (Hence the thread above re costs in that period).

So say heaters could be on 0038 to 0638 GMT winter / DST in summer time - and if still drawing power that last 8 mins (maybe unlikely by DST) would be billed at peak not the cheap 9p off peak rate.

Because its in the 0630-0700 meter 1/2 hourly register and billing at peak slot on 1/2 hourly basis.

So on tariffs using half hourly - if you were setting your own heater timings - maybe - assuming 6 hours long enough - best set to stay within tariffs core off peak - in Snugs case the 0030 to 0630 guaranteed cheap billing window - ignoring the 8 mins.

And the same maybe applies to the equivalent afternoon boost period (but the time isn't guaranteed but didn't seem to change randomly either from users charts in above Snug thread).]

Of course if you only needed say 2-3 hrs of power overnight to heat certain heaters or hot water immersion tank say - you could set everything up well within the boundaries - for the offset - and any GMT/BST switching - tariff or timer or both - and just leave them. Many for instance only heat HW tanks 1-2 hrs a night.

lilac_dawn

I know. I have suffered E7 for just over 20 years now - although thankfully not always as a permanent resident. I am very used to staying up and watching exactly when the meter switches to a different tariff and when the lights come on the E7 circuit.
But it looks like I am going to stick with UW for the next couple of months and then see what they do in Jan.

Scot_39

sorry was spelling out the main timer issues after the "lost me" comment