Energy monitor installation...

[Jake]

I applied for a free energy saving monitor in an internet offer a few weeks back and it has now arrived. It comes with a clip that fits over the cable from your meter and transmits your usage, presumably by measuring the current induced in the clip and calculating W = V x A.

It says I need to attach it to the live cable - and has a graphic of attaching it to the furthest right cable out of four, 2 in and 2 out of the meter.

In my situation, the meter is outside and the cables pass through a wall before they run inside my consumer unit, and it is not possible to differentiate between the two.

Does it matter whether the clip attaches to the live or the neutral?

[The Natural Philosopher]

[John Rumm]

Would not have thought so - same current will flow in both.

[TheOldFellow]

Try it, they are usually easy to put on and off. Mine works fine on any of the four cables going to the meter.

The more important thing is the place it where it has the least shielding from pipes and large earthed metal things.

R.

[Harry Bloomfield]

It should work equally well around any one of the four cables.

[Brian Gaff]

Four cables? Anyway, any of these devices have a spoken output or interface to a computer so one can download the data and get it spoken in that way instead?

Brian

[Harry Bloomfield]

Brian Gaff brought next idea :

I understand some do have a computer interface enabling data to be downloaded, but I've not seen one which can speak the data.

[Andy Burns]

L+N into meter, L+N out of meter. My old one didn't even attempt to say which cable to use, just clip it over one of then ... which was fine.

The CurrentCost ones have a serial port (TTL level I think) mine also came with a USB lead to connect into it, the protocol spits out gobs of XML with recent and historical summary data.

I think it would make rather boring listening! there is open source software around that accepts the data, doubt that has voice output either.

[The Natural Philosopher]

Gridwatch grabs XML data. You could have your own domestic gridwatch :-)

I am slighlty tempted..

[Andrew Gabriel]

Beware - there's been some talk on the home automation channels that the currant range of products are much more difficult to interface to, and that simple serial or USB data streams are a thing of the past, with the current products having undocumented proprietary USB interfaces.

OWL do a separate black box receiver which can feed directly into a computer, but it will only work with their application, which is a pile of rubbish, and requires the PC on 24x7 running their full screen app, which isn't going to appeal to anyone interested in having a cost meter! A good idea, destroyed by a useless implementation which fails at every level.

[Alan]

In message , Brian Gaff wrote

You can get a separate remote USB receiver for the Owl brand model but the PC software that comes with it is not too good. I cannot remember if it mimics the display or just logs the data to give a graph of usage.

In my experience these monitors are most useful for around a week, before the novelty value has worn off. In the first week you can see if turning things on, off or in standby can make a significant difference to the bills.

An occasional glance at the meter now may indicate that something power hungry has been inadvertently left on.

[Andy Burns]

I already have a server chuntering away 24x7, I like the idea of making it sing for its 120 watt supper in as many ways as possible, I run cacti in one VM to monitor ADSL router and UPSes, that was where I planned to feed the CurrentCost data.

It would be nice to feed the smartmeter data into it (especially as the gas consumption is now available) if anyone knows about M-BUS or that Amber Wireless dongle? Mr Gabriel perhaps?

Then a noddy weatherstation to grab wind/temperature data and occupancy sensors in all rooms and 2-port valves on all radiators, link it into the GPS on my phone so it knows when I'm setting off to return home, all I'll need then will be the white cat to stroke menacingly ...

[The Natural Philosopher]

Yes..I like this 24x7 monitoring stuff and turning the desktop PC into a 'home control room'

[Owain]

... and an internet cat-feeder

[Dave Liquorice]

I'm inclined to agree but I quite like having a plot of daily power consumption available from my server.

They aren't really sensitive enough to show how much that Sky box is taking in standby/on or anything of similar low power. What it might pick up is combined low level consumption, I'd really love to know what is taking the 300W that our consumption never drops below. I guess is a combination of "essential" routers, PABX, couple of lights, server etc etc but even "essential" stuff I'd like to reduce the comsuption of. 300W is 7 units/day about 1/3 of the daily total (ish), halving that would save over =A3100/year.

[Andy Burns]

When I totted mine up a while back ...

Doorbell transformer in C/U Non-maintained emergency light in cupboard under stairs (where C/U is) TV distribution amp in loft Programmable stat for C/H programmable stat for UFH clocks on microwave, oven (VCR flashing 12:00 is long gone) Bedside radio/alarm (DAB in my case with greedy non-switchmode wallwart) Any other wallwart that gets warm even when unused Two UPSes (now reduced to one) and a MasterSwitch DECT base-station and charge-stations ADSL router VOIP adapter Ethernet switch Wifi Access point/firewall Security light on PIR sensor low level security light on dawn-to-dusk sensor Battery charger(s) laptop docking stations/monitors/USB hubs/powered speakers Interlinked smoke alarms Plugin display for smartmeters itself!

they all add up, If I shutdown my server I can get the rest of the house to around 200W while the fridge freezer is not running, 250W when it does kick in.

As mentioned I do (usually) have a server running 24x7 so I trickle along at an average 400W which I don't think is too bad,

Tempted by Andrew Gabriel's syphoning-off of 12V and 5V from the server to run as much of the ADSL/DECT/VOIP/Ethernet/WiFi kit without individual wall-warts ...

[dennis]

I had a smart meter fitted and it will pickup low level standby power.

Mine would be the pond pump, fish tank filters/lights/heaters, router, NAS, WAP, sky box, mail server, alarm, fridge, freezer, outside light/pir, security camera, CH timer..

[<me9]

The readings on my Owl (and almost certainly other similar devices) are very misleading. According to it my microwave takes about 80watts on standby. My plug in energy monitor says 5.5w with 0.07 power factor. When my fridge or freezer (inductive load) come on with the microwave connected they take only a few tens of watts, mich less than their rating, due to the power factor correcting of the (capacitive) microwave mains filter (effectively 4.4uF across the mains taking 380ma)

I'm thinking of using a spare owl current probe into a plug in energy monitor to do the correct sums on the incomig feed, or even into computer sound card(via isolation), I&V seperately digitalised and multiplied for full details, but I haven't the programmng skills for that (could prolly do it on a BBC Micro theough!)

[ARWadsworth]

You forgot the nurse call alarm.

[Ghostrecon]

I've been comparing mine now for just a year or so - mine under-reads multiplying by 1.09 on the comparison spreadsheet is enough to match it generally.

Managed to get 160kWh per week down to 100 KWh over the course of a year - base load is now down to about 70W, fridge freezer and freezer kicks in to push it up to 350 on a regualr basis.

My currentcost meter feeds a netbridge which feeds a pachube free account so gives 24/7 data across the internet/smartphone etc without running a computer.