Electricity Useage Monitor

Mint Sauce

Considering buying an device to monitor my eelectricity usage, something like this or similar https://www.amazon.co.uk/gp/product/B001Q1G4WK/ref=s9_acsd_hps_bw_c_x_1. Anyone have any experience with them, and does Electric Ireland have any issues with you attaching the sensor to the cables in the meter box.

Thanks in advance.

Steve

You can't put anything in the meter box without the approval of ESB, doesn't matter who is selling you the electricity.

At best, this would go inside your fuse board (the current sensor bit) so if you think there is room then fire ahead.

Mint Sauce

Steve wrote: »

You can't put anything in the meter box without the approval of ESB, doesn't matter who is selling you the electricity.

At best, this would go inside your fuse board (the current sensor bit) so if you think there is room then fire ahead.

Is it not kinda dangerous to open the fuse board. No visable cables running in or out of it.

Steve

Mint Sauce wrote: »

Is it not kinda dangerous to open the fuse board. No visable cables running in or out of it.

Yes, it's dangerous.

Basically, you have to clip the sensor (current transformer) onto the main feed into your house.

You can do this in the ESB box but it breaks a heap of regulations, maybe it's OK in the UK where the item is sold but not in Ireland.

The only other option is to take the cover off your fuse box and clip it onto the main feed.
Not dangerous if you are competent and know what you are doing but not something I would recommend to a 'diy' person.
Mostly, you will find that there is not enough space for it, it entirely depends on the installation.

If you feel you are up to the job, by all means take the cover off and post a pic here and I can say where to attach it but I wouldn't recommend it if you don't have electrical training as IT COULD KILL YOU!!

Mint Sauce

Think I might skip it. Thanks for the input anyway.

Big Dec

Hi,

Sorry to jump in a slightly different direction, but anyone know of any meters which I could use to measure multiple supplies?
I have a heat pump & heat recovery and would like to monitor these separately.
I deally, I would like to have 3 (or more) measurements:
1) Overall kWH & cost
2) Heat pump kWH & cost
3) Heat Recovery kWH & cost
I moved into a new build last October and would like to track my usage & be able to save the data to excel or otherwise.

I was looking at the owl intuition-e, and possible getting 3 of them as there doesn't seem to be an option to have 3 clamps for one unit.
They seem to have a nice app & PC interface.
Anyone know of other units I could get?

Thanks,
Dec.

Steve

Might be worth an email or phone call to Owl to ask if their 3-phase unit will work on single phase, it might.

There are plenty of industrial alternatives out there but none close to the Owl / Efergy price level. e.g Episensor or ND or a host of other IP enabled meters.

Big Dec

Thanks Steve.

I was in touch with them after I had submitted here.
The 3 phase one would give me what I want in terms of kWH, but not the cost side of it.
It would give me the total kWH & cost for main feed, but only kWH then for the other two.
I suppose I was most interested in the heat pump side as this would be one of the biggest single contributers.
I see on Amazon, that I can get the single phase unit for ~€65, so maybe 3 of these is still a very good option?

Steve

Costs are easy to work out if you can get access to the raw data. You know what you are paying per kWh used and per day standing charge, just apportion it out.

The Efergy one is on Maplin and available in Ireland for €45 each.
http://www.maplin.ie/p/efergy-elite-wireless-energy-saving-monitor-n26gg

Only issue is it doesn't say if you can download from it.

Calahonda52

Big Dec,
In reality, you only need the kWhs as the other elements in your bill are fixed costs so you will very quickly get to grips with it.

Unless the interface with the meter is easy, its a pita to be keying in rates at the meter.

I have an ND meter with three CT's and its grand, I also have a data logger which was not cheap but I need it for other stuff.

Split coil CT's are not cheap and in your case I would consider sticking a standalone meter in line on the heat pump with a run hours option as well as its not just the kWh but you also need to know how long it is running: it may be on the pump itself so just hack into it!

The HVR would not concern me as if its 90% + efficient, then you are looking at 10% cost

Wearb

Wemo Insight will do exactly that. You can change the cost per Kw in the app. You can also use IFTTT to automatically upload an excel file to google Sheets

Big Dec

Hi Calahonda,

I have never used one of these meters before, so am not sure how I would work out cost on a dual tariff.
Would I be able to determine this myself?
At the end of the day, all you want are the kWhs & then let excel do the rest. :-)
I think there is some sort of log ont he heat pump, but this is not available through the general user interface.
What sort of meter would you suggest installing in line with the heat pump? (PM if required)

I have been looking around & see that Garo have a number of meters under the Socomec brand although I'm not sure which type would be suitable.

Calahonda52

The dual tariff is just going to be time based in excel
Socomec is good gear as well, some come with inbuilt data loggers which can be accessed pretty easily.
I have seen lots of them on distribution boards in factories with CTs onto the mains
This is what I have
https://www.shmmetershop.co.uk/shop/northern-design-rail-310v-retro-fit-triple-single-phase-multifunction-kwh-meter.html
Bought it from ND but I needed it for an industrial application so not really a domestic unit

I don't have a meter in mind for your heat pump but I am guessing that if it draws say 40 Amps, then an inline meter might be cheaper than a split CT, meter and data logger, maybe not.

Attached find a simple half hour [HH] MRSO file that will get you started: I couldn't upload it as cvs which is the raw format
half hour reading, time across the top, days down the side.

This is a note on how to do the math, lots of guys screw it up:D

So if you do the excel for the same time period as your bills you can easily check your math for total KWhs against the actual bill, assuming you give then an actual reading and not an estimate

Each value in the raw data file is a kW reading every 30 minutes
so at
00:00 say it is 100 kW and at
00:30 say it is 110 kW

The assumption is that the reading says the same till the next reading.

So the average for the hour from 00:00 to 01:00 is (100 kW by 0.5h + 110kW by 0.5h) = 105kWh

ps: for testing your math, July 16 usb bill was 132,112

You will get 132,011 or so which is close enough.

Mint Sauce

Mint Sauce wrote: »

Considering buying an device to monitor my electricity usage, something like this or similar

I have something similar. It's better than nothing but pretty dumb. I power the sense - transmit unit from USB
Mine's highly inaccurate at the low end, voltage is assumed and it only reads positive current so my daily usage is way off because it reads my grid tie solar export as a load. :rolleyes:

air

While strictly speaking Steve is correct and nothing is allowed in the meter box, I've had one in my meter box for about 5 years including during a meter upgrade without any issues.
From a practical point of view it's hard to see ESB Networks having any issue with the sensor and it's definitely a safer place for the average homeowner to install it themselves.
Big Dec - have a look at the OpenEnergyMonitor project, it's a little techy but it can do what you want, will measure consumption of all your devices and you can even view consumption in real time on your phone if so inclined.

Big Dec

Thanks.

THis was the sort of unit I was looking for.
I'll be reading up on it over coming days.

Do you have one yourself?

air

I have an Owl meter and an Onzo brand one.
I also have an O.E.M. kit but haven't installed it yet.
I have a grid tied PV system which I hope to monitor with the O.E.M. hardware eventually.

ted1

Steve wrote: »

Yes, it's dangerous.

Basically, you have to clip the sensor (current transformer) onto the main feed into your house.

You can do this in the ESB box but it breaks a heap of regulations, maybe it's OK in the UK where the item is sold but not in Ireland.

The only other option is to take the cover off your fuse box and clip it onto the main feed.
Not dangerous if you are competent and know what you are doing but not something I would recommend to a 'diy' person.
Mostly, you will find that there is not enough space for it, it entirely depends on the installation.

If you feel you are up to the job, by all means take the cover off and post a pic here and I can say where to attach it but I wouldn't recommend it if you don't have electrical training as IT COULD KILL YOU!!

Is it not a current transducer rather than a current transformer. I'd also say it's safer to out in the meter box over the consumer unit, as there are no exposed busbars

ted1

Big Dec wrote: »

Hi,

Sorry to jump in a slightly different direction, but anyone know of any meters which I could use to measure multiple supplies?
I have a heat pump & heat recovery and would like to monitor these separately.
I deally, I would like to have 3 (or more) measurements:
1) Overall kWH & cost
2) Heat pump kWH & cost
3) Heat Recovery kWH & cost
I moved into a new build last October and would like to track my usage & be able to save the data to excel or otherwise.

I was looking at the owl intuition-e, and possible getting 3 of them as there doesn't seem to be an option to have 3 clamps for one unit.
They seem to have a nice app & PC interface.
Anyone know of other units I could get?

Thanks,
Dec.

For the heat recovery, are you looking for electricity or energy?
With heat recovery the standard would be to monitor the electrical consumption along with the actual heat on KWH that is being recovered.

air

ted1 wrote: »

Is it not a current transducer rather than a current transformer. I'd also say it's safer to out in the meter box over the consumer unit, as there are no exposed busbars

It's a current transformer but a CT is a transducer so you're both correct.
This is one of the most commonly ones used:
http://www.yhdc.com/en/product/320/

ted1

air wrote: »

It's a current transformer but a CT is a transducer so you're both correct.
This is one of the most commonly ones used:
http://www.yhdc.com/en/product/320/

A current transformer had a current output and can kill you if left open circuit .

A current transducer has a DC voltage output or a mA output and is much much safer.

air

ted1 wrote: »

A current transformer had a current output and can kill you if left open circuit .

A current transducer has a DC voltage output or a mA output and is much much safer.

They're one and the same thing, a CT is a CT, it's only how it's output is connected that's different.

If you want a CT with a voltage output you select one with a burden resistor.
It produces an output voltage proportional to the sampled current.

If you want a CT with a current output you select one with a clamping diode on it's output which limits the maximum voltage on the output to a safe level.
The output current is proportional to the sampled current.

If you have a look on the link I posted you will see they offer CTs with both types of output.

ted1

air wrote: »

They're one and the same thing, a CT is a CT, it's only how it's output is connected that's different.

If you want a CT with a voltage output you select one with a burden resistor.
It produces an output voltage proportional to the sampled current.

If you want a CT with a current output you select one with a clamping diode on it's output which limits the maximum voltage on the output to a safe level.
The output current is proportional to the sampled current.

If you have a look on the link I posted you will see they offer CTs with both types of output.

They are similar but not the same.

air

They are exactly the same, it's only how the output signal is conditioned that's different.
Swap the resistor for a TVS diode and they can be used interchangably.

You said that a current output CT can kill, this is true but only if they don't incorporate a TVS - which they all do in my experience.
Anyway, wandering totally OT.

ted1

air wrote: »

You said that a current output CT can kill, this is true but only if they don't incorporate a TVS - which they all do in my experience.

So there's no need for drop link terminals??

air

I don't see where I mentioned anything about termination or where you are going with this to be honest.

Steve

ted1 wrote: »

Is it not a current transducer rather than a current transformer. I'd also say it's safer to out in the meter box over the consumer unit, as there are no exposed busbars

As air explained, there is little difference between a transducer and transformer, the innards are 90% the same.

Yes it would be safer in the ESB box but it's against regs to put it there.

Big Dec

@ted1
I'm just looking for an electricity monitor.
I'll worry about energy down the line, but it is electricity consumption I'm trying to moinitor for now.

@air
I had a good look at the Open Energy Monitor site & purchased a system from them.
Seems like exaftly what I am looking for with scope for future expansion.
I think it works out at €220 for what I purchased.
1 x emonTX
3 x clip on CT
1 x AC-AC adaptor
1 x emonBase

Will be off work for a few days next week, so will try to get it up and running.
Looking forward to seeing how it works out.

batman1

Any reasonable plug-in types available ?

air

batman1 wrote: »

Any reasonable plug-in types available ?

There are plenty but they are obviously only designed for single devices and wouldn't tend to have remote access cababilities.
The clip on CTs typically used mean you can monitor the energy usage on circuits far greater than that covered by a 13A domestic plug socket.

Big Dec

Hi,

Just a follow up on my installation of the open energy monitor in my house.
I have it in a few months now & love it.
Very easy to view graphs & dump out csv's if required.
At the moment, I'm still just playing with it & not using to full potential but I hope to get a better idea of how my heat pump is working this winter.
There is a nifty interface where you can create your own little widgets & I have some which look like speedometers from cars which show me instantaneous usage.
I would highly recommend to anyone who wants more than just the basic plug in monitor.

Thanks to @air for the recommendation.
A few of the guys in my office have also purchased.