Smart Power Meter, distinguish between 2 readings?

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snowfly

543 posts

Ultimate Geek

#198120 27-Jun-2016 16:32

Our house has an EDMI Atlas Mk10D smart meter for electricity, and has 2 separate kWh readings, and both are increasing, suggesting different parts of the house go to either of the 2 readings.

The meter might have been originally put in via Genesis, as their stickers are around it, but we actually use Nova, who don't do smart meter readings (instead manual), and can't say why the 2 readings, we just always get 2 line items on our invoices.

On the meter screen one reading is labelled "24Hr", the other "Ctrl", which suggests a 'controlled' type meter, which from what I understand is typically used for electric hot water cylinders (or other wired appliances) and the lines provider can potentially switch off these devices for short periods during high load.
But we have mains gas infinity hot water, no cylinder.

One thought was the separate garage contributed to one reading, but that theory failed when I turned everything off in shed, took readings over a day, and both readings still increased.

Can anyone suggest a way of trying to establish which parts of the house are connected to which reading?

As I'm curious to know which parts of the house contribute to which reading, and whether I can change power plans to take advantage of things like lower night rates, or similar.

Perhaps using some sort of power monitor? Either every device, or at the meter itself?

xcubed

194 posts

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Lifetime subscriber

#1581241 27-Jun-2016 16:48

I agree that it's probably for a controlled load, that the supplier can remotely turn off if necessary, when they need to shed excess load, etc.

The meter will have a separate live feed from the meter to the distribution board, and it should be used by one or more circuits on the distribution board (ie: the feed won't go straight to an appliance). With any luck, your distribution board is clearly labelled as to what each circuit is used for, so while you probably won't know which circuits are controlled, you might be able to make a guess and verify it by checking that reading on the meter once that circuit is turned off.

Hot water is the most common, but other loads are possible, such as night store heaters, heat pumps, water pumps, etc. A controlled load is something that should be able to be turned off safely at any time, and should be a reasonably large load (otherwise there's nothing much to be gained by turning it off). It's unlikely to be feeding any lighting or wall sockets.

richms

28191 posts

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#1581269 27-Jun-2016 17:09

That is what I had for a while after the smart meter went in replacing 2 analog meters. The pricks changed it, before I had a 63A breaker for one and a 32A fuse for the other meter, with the second one doing the shed power since the last owners had a business in there. The new install had them all going thru the 63A breaker and then the fuse went after that, so I was now limited to 63A for the house and shed even tho the pole has 80A in it.

After the new meter went in, the CTRL was the sheds power, and the 24Hr was the houses power. Then genisis sent me a letter that I was on the wrong rates and moved me to a night plan or something, and they started to bill the CTRL at a lower rate even tho it was on all the time. So I moved all the servers to the shed since the power was cheaper.

Then a year later they sent me another letter saying that it was a mistake and that I had to go on another plan where the house was _way_ more expensive than the CTRL, I tried reasoning with them that I had 2 meters that were the same price before the smart meter went in but they insisted that i had a controlled load.

So I had them pull that meter out and put in a single register meter, which then later on got changed for one with import/export.

Richard rich.ms

Aredwood

3885 posts

Uber Geek

#1581530 27-Jun-2016 21:21

If the house has (or used to have) a spa pool. The controlled load might be for the spa heater. But then the spa get removed and a power point installed on the circuit instead. Also underfloor heating is another common load to be on a controlled circuit. I have seen houses with 2 smart meters for the one house. and the second smart meter will sometimes show a really low usage. Something like 6 units total despite the meter being installed over 3 years ago.

Wish my house had a second meter like that. Then I would be able to get the second meter signed up to a different power company. And leave the main meter on Flick electric. Then I could switch load between the meters depending on which company has the cheapest power currently.

Check the stove as well. It might be wired to 2 phase power, meaning the top elements will be wired to 1 of the registers. And the oven, warming drawer ect connected to the other register.

Amosnz

567 posts

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Lifetime subscriber

#1581624 27-Jun-2016 23:09

We also have 2 meters (both analog), gas hot water (cylinder not infinity - yet), and are with Nova.

Our bill lists the meters as Anytime and Controlled usage is split about 60/40. I spoke to Nova's helpdesk quite a few years ago about it (as I was worried about half my house going dark during high load) and they said it is highly unlikely they would control it. So far they never have but 40% of my electricity is at a cheaper rate.

I use an engage to monitor our whole house usage. http://efergy.com/nz/products/energy-gateways/engage-hub-kit

When I first brought it I clipped the clamp around individual circuit wires in the fuseboard (instead of the mains in) and worked out what was connected. Not only could I label the circuits better but I got a very good idea of how much power was being used instantly, even from the lights (which you cant meter with a plug-in meter).

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