Energy monitor / base usage

JennyR68

Cardew wrote: »

There is plenty of conjecture that at very low consumption these monitors are wildly innaccurate.

I cannot 'find' where about 100W is being used.

My minim is innaccurate at any consumption, it's out by around 5-7 units a day.

From what I understand they cannot give a 'true' read as it can only measure amps and has to assume a constant 230v which we don't all have. My volts are reading 243 on my socket monitor!

uptomyeyeballs

JennyR68 wrote: »

My minim is innaccurate at any consumption, it's out by around 5-7 units a day.

From what I understand they cannot give a 'true' read as it can only measure amps and has to assume a constant 230v which we don't all have. My volts are reading 243 on my socket monitor!

Can you not set the voltage to be more representative? I know it's configurable on my monitor. I know it's only an estimate, but it at least allows you to see what the main culprits are. 0.1 kW seems a reasonable baseline when calibrated against the actual electricity meter usage. e.g. if I read the actual electricity meter before going to bed and immediately on getting up, it indicates it has used 1 kWh in 10 hours.

If you calibrate your gear first, you'll get closer.

JennyR68

uptomyeyeballs wrote: »

Can you not set the voltage to be more representative? I know it's configurable on my monitor. I know it's only an estimate, but it at least allows you to see what the main culprits are. 0.1 kW seems a reasonable baseline when calibrated against the actual electricity meter usage. e.g. if I read the actual electricity meter before going to bed and immediately on getting up, it indicates it has used 1 kWh in 10 hours.

If you calibrate your gear first, you'll get closer.

Not as far as I'm aware, I know with the latest owl you can but have searched through the instructions for the minim and can't see same facility. I think it's just set to 230. It's labeled an entry level monitor though so can't expect it to be too sophisticated I suppose.

Dave_save

The one I have is an Efergy monitor, and this enables the change of voltage setting. However, I think they all work on the same principle of sending a pulse every few seconds to the monitor, which is a 'snapshot' current reading. Therefore I don't believe any of these type of monitors are accurate, due to voltage fluctuations and also due to changing current between the pulses which is not picked up by the sensor.

My meter can read a usage of 10kWh during the day. Over the same period the monitor will record between 8 and 9kWh. It never matches.

JennyR68

Dave_save wrote: »

My meter can read a usage of 10kWh during the day. Over the same period the monitor will record between 8 and 9kWh. It never matches.

At least my monitor records extra, it's always nice to read the meter and see it's less.

uptomyeyeballs

Dave_save wrote: »

My meter can read a usage of 10kWh during the day. Over the same period the monitor will record between 8 and 9kWh. It never matches.

You therefore have a calibration factor for your particular meter.

kevsan

I have an owl one. and its great for a while, but you get used to it being there... it was good to educate the wife in terms of seeing it shoot up when the hob/kettle/tumble dryer was on.

As others have said, its not brilliantly accurate, but good for a ready reckoner.. For more accurate results, read your meter once a week (or day if you must) and stick it in a spreadsheet to track your usage.

davetaylor

OK thanks. I am watching a couple of Owl CM119 in ebay at the moment. There is a 'buy it now' going for £22.00 which seems like a good deal..