E7 meter switching

[Richard]

Looking at this set up, its wide open to fraud, with a simple link inside the house from the main fuseboard to the offpeak board during the day you can switch the meter to the lower tariff.

[John Rumm]

I just read Andy's comment about the way rate switching was being done by providing a neutral to a normally open circuit connection, as was wondering why they did it like that. You just answered my question!

[Sparks]

That won't switch the meter over, the switching is done by the thin grey wire connecting the meter to the time switch, the far right and far left tails into the time switch won't me connected to this wire inside the time switch.

Live and Neutral enter the time switch via the two fat grey cables (one has red tape around it) this powers the timer. when the timer is in night mode, the live (or neutral, I am not sure) from these wires is directed to the meter via the thin grey wire. The time switch also has a separate switching mechanism that directs power from the far left tail to the far right tail, so back-feeding power down the far right tail won't make the meter switch to night rate, it won't do anything other than making your E7 circuits live, the storage heaters would try to draw all their current via this link (at the day rate) and if you created this link with too smaller wire, it will overheat, causing a fire risk, so DON'T DO IT!!

Sparks...

[Sparks]

We had E7 installed about 3 years ago (Maybe a little longer) and my setup is the same (Except I have a radio Teleswitch in place of the timer)

Sparks...

[Richard]

Appears to me that when the economy 7 outgoing tail from the time clock becomes live the thin grey wire is energised to switch the meter to the lower tariff. Because that cable appears to be common to the e7 feeder, if you were to put 240v on the main incomer on the e7 board surely this would switch it to low tarrif, it would be prudent to leave the main isolator on the e7 board open circuit, otherwise you will have a possible 100kw load on that thin grey wire. Whatever that grey wire carries to switch the meter it can be mimicked, highly illegal,not very secure on the providers part though.

[Ron Lowe]

Hmm, that's a safer way to fraud, then.

A nice low-current low-risk fraud: Tap into that wire, hook to N will effect a switch in the metering?

Much safer than an attempt at fraud in the original manner suggested, which would require back-feeding L from the permenant-L CU to the ( supposedly ) dead switched CU to trigger the meter, because the same back-feed would also be providing the only main L feed to the switched CU, surely? The backfeed wouldn't close the contact in the timeswitch.

So although the meter would see the L on the switched side, and go to lo-rate, the actual power would also be delivered over the link. ( I'm imagining a low-wattage user interlinking the circuits with a 0.75mm^2 flex here. )

[Richard]

The aim is not to close the switch in the timer, we are not trying to energise the e7 board the storage heaters are on low tariff anyway, the idea is to draw your daytime units at the e7 rate which possible whilst leaving the e7 board open circuit, dont forget you have 2 seperate consumer units.

[Andy Burns]

looks like 2.5mm^2 T+E to me :-(

Feeding into SWA for an external run?

[Sparks]

According to Andy, (who I am inclined to believe, as he knows what he is talking about!) this thin grey wire is pulled to Neutral to tell the meter to switch to night rate, but even if it did go live, shoving live into the far right tail would not mean live then is applied to the thin grey wire. The far right & left tails will be electrically isolated from the thin grey wire. All the time switch does, is connects the far right tail to the far left tail, AND also connects the thin grey wire to the neutral that enters the timer via the thick grey tail.

No, see above.

The only way to do this would be to cut into this thin grey wire, but then when the eclectic company sees this tampering, you are in big trouble!

Sparks...

[John Rumm]

Safer, but will need to be done in the meter box rather than discretely in your home, which will make it a little more obvious!

The meter needs to see N on its rate select input, the actual power to the E7 circuits is delivered via the Henley block and the timeclock. To enable these at times other than cheap rate you would need to provide an alternative (and substantial) live feed to the switched CU as well as the dodgy business with the rate control wire to the meter.

[Richard]

Is it just me or is everyone missing the point here, ok so its a neutral thats required and its not commoned up at the time switch, the idea is not to power up the storage heaters during the day, why would you wish to do that? It is to run your tumble dryer immersion heater boost etc on cheap tariff during the day, a neutral from anywhere would do, not so good now it needs to done in the electric companies box, otherwise it could be set up as a wiring fault in the house.

[John Rumm]

I don't think we are missing the point... I understand that the desire would be to frig the meter to record "normal" daytime usage as if it were cheap rate. I was partly responding to Ron's post about feeding power via any linkage - by saying that if you did want to power the switched CU as well as just change the recording, then you would need additional substantial linkages, and you would not end up trying to pass significant current via your control link.

All these systems are open to abuse at the physical level. The defence against many of them is not only by spotting the problem at the physical level (although with an unusual mod in the meter box it is marginally possible it would be spotted[1]), but also at the database level. When your usage patterns change out of "character", software will flag it up for investigation.

So if you were going to syphon off extra cheap rate units you would have to be sparing in doing so, so as not to arouse the curiosity of the heuristic scanners (which makes the whole exercise less rewarding anyway). It would also be best done when you are new to the property and they would be expecting a change in usage (which is also the time you are probably more likely to get extra visits to "read the meter" etc).

[1] With the outsourced "data collectors" who are not usually specifically recruited for their detailed knowledge of domestic wiring who read meters these days, it would probably need to be a fairly obvious looking bodge to be spotted.

[tony sayer]

Like an old mate of mine once said..

If you see a barrel load of half Crowns, just have a few off the top every now and again;)

[Richard]

Im not going to do it for real and if i was I wouldnt be posting on newsgroups, just an interesting frig thats possible, I love find ways defeat systems, a prepay meter would be a nice one to have a look at. Anyone got a photo of such a setup.

[Owain]

I don't think any power company uses prepay meters any more, in the true sense. They use prepayment cards for collecting payment to the customer's account, and perform an annual reconciliation between the payments received and the electricity consumed. All the meter does is ration the electricity to approximately the same usage as the payment. It's very possible for the two to get out of track - when I had a prepay meter I got a refund back most years.

Even if you could get the prepay meter to give you electricity without using a card, you would come unstuck at the first annual reconciliation because they would find you'd used electricity which hadn't been paid for. This is also why using someone else's powercard doesn't actually save any money.

The only way of defrauding a prepay meter is to bridge it.

It's also likely that prepay meters are read more often, both to reset them when the rates change but also because the power co thinks "that type of customer" has a greater propensity to commit theft.

If you ask really nicely I'll tell you how you can make free phone calls :-)

Owain

[Sparks]

So where would you connect this Neutral to?

The ONLY place you could connect it to, would be to the small grey wire, but both ends of this wire are protected by sealed equipment (Meter one end, and the time switch the other), if you break the seal on the equipment, then when the electric company notices, and they will, eventually, you will be in a whole heap of trouble!

Sparks...

[Richard]

Just ring the insulation near to the equipment with a stanley, it will just look like the original sparky that installed it was a bit slapdash you only need a couple of mm, enough to put the signal down there. Failing that it could be done with a dart or a pin. Plus im pretty certain you could push a solid single core 1.5mm up into the connection.

[Midboy]

The New Digital Meters when installed have already been programmed to switch on,.. Some at 0.30 hrs then off at 7.30hrs ....Times may vary in different areas They are new meters with already an internal backup battery to keep the clock correct ... when first energised when you press the button it shows the time the date as well as the actually meter reading and the programme is already set within the meter.. on a microprocessor .. With these, if you have specific OFF PEAK Circuits IE storage heater ,...Usually there is 5 terminals coming out of the meter live - neutral IN ( Normal ) live - neutral OUT (Normal ) The 5th terminal Live go to a specific off peak only fuse board and only becomes live when the preprogrammed time switch within the meter ..(IE 0.30hrs switches ) This 5th terminal becomes dead again when it switches out IE 0730hrs The 4th terminal is live normal daytime and remain live all the time ...

Before there were Radio Controlled teleswitches ( maybe still in service ) they could be varied by the supply authorities to control switch on and off times ..... to stagger loads on the national Grid ....... but the digital ones are preset usually if you look on the front of the meter it usually says what time period like IE.....0.30-07.30 Hope this helps Midboy :)

[Brian Sharrock]

My E7 (actually the supply company's then trading as SeeBoard) has a clunky electro mechanical device; - there's a rotary clock cam with pointers ON and OFF; as the clock dial rotates and the pointers pass under the dial either the DAY meters increment or the NIGHT meters increment. It matters not to the house (loads) which meter is incrementing. There's no time-gap between the switching. All controllable devices, dishwasher / washing machine / tumble dryer have time switches which only operate during the NIGHT metering.