Plug-in energy monitor

Section62

aaiiee said:

I have an ENERGENIE  model ENER007 batch code 2321, bought a few months ago. I've found it very useful - I've only used it to measure current and accumulated power use (kWh). When you remove it from the plug socket, the display continues to show the latest stats for a few seconds (not very long). In really inaccessible places, I have resorted to taking a photo of the display with my phone.

Does yours have LR44 batteries installed behind a screwed on panel on the back?

aaiiee

I've just unscrewed the back - no, no batteries!

Astria

Section62 said:

Astria said:

Spies said:

3kw would be plenty unless you have a it plugged into a fast boil kettle as they can pull 3.3kw. 

I'd like to see that considering our power supply is typically 240V @ 13A, so 3.1kW is the absolute maximum. Most kettles are 3kW for this reason. Industrial kettles typically use more but also typically permanently wired.

13A is nominal.  A 13A fuse plug top fuse will allow 20A to pass indefinitely.

So 3.3kW on a 240v supply = 13.75A, well within the tolerance of a 13A fuse.

Many domestic appliances may draw peak currents in excess of 13A, whilst rated much lower than that. Inductive loads (e.g. motors and transformers) are more of a problem than resistive loads (e.g. most kettles).

I agree with you as I'm aware of that, but I'm still skeptical that a company will sell a 3.3kW kettle, knowing they are exceeding the nominal 13A rating they supply in the plug. Do you know of such a kettle ?

Section62

aaiiee said:

I've just unscrewed the back - no, no batteries!

Thanks. That matches the more recent instruction manual.  Perhaps a redesign to get rid of an annoying/wasteful method of backing up the stored information.

Spoonie_Turtle

aaiiee said:

In really inaccessible places, I have resorted to taking a photo of the display with my phone.

This is what we do for our electric meter - it's not completely inaccessible, but awkward, and it's good to have a record anyway.

A bit left-field but I came across this one https://lowenergysupermarket.com/product/plug-in-energy-monitor/ via eBay which looks to have a display exactly like our meter, which I know photographs well and is usually readable anyway if we can stick our heads into the cupboard.  They were very responsive on eBay and have said it does have a reset / zero function for moving between appliances.

Section62

Astria said:

Section62 said:

Astria said:

Spies said:

3kw would be plenty unless you have a it plugged into a fast boil kettle as they can pull 3.3kw. 

I'd like to see that considering our power supply is typically 240V @ 13A, so 3.1kW is the absolute maximum. Most kettles are 3kW for this reason. Industrial kettles typically use more but also typically permanently wired.

13A is nominal.  A 13A fuse plug top fuse will allow 20A to pass indefinitely.

So 3.3kW on a 240v supply = 13.75A, well within the tolerance of a 13A fuse.

Many domestic appliances may draw peak currents in excess of 13A, whilst rated much lower than that. Inductive loads (e.g. motors and transformers) are more of a problem than resistive loads (e.g. most kettles).

I agree with you as I'm aware of that, but I'm still skeptical that a company will sell a 3.3kW kettle, knowing they are exceeding the nominal 13A rating they supply in the plug. Do you know of such a kettle ?

I wasn't commenting on the availability of 3.3kW rated kettles, only that 3.1kW isn't an 'absolute maximum'.

I also don't believe that Spies was saying that 3.3kW rated kettles are available, only that some kettles can draw that amount of power.

For example, a kettle nominally rated at 3kW at 230V will draw significantly more power when operated at 240 or 250V.  Very roughly, say 3.2kW @240V or 3.5kW at 250V.

They won't sell it as a 3.5kW kettle though, because the nominal standard mains voltage in the UK/EU is 230V.

However, when buying and using test equipment, we need to be aware and careful over the differences in practice between nominal figures and the actual ones.  Especially with cheaper/low-end kit that might be operating close to the extreme anyway.

Section62

Spoonie_Turtle said:

A bit left-field but I came across this one https://lowenergysupermarket.com/product/plug-in-energy-monitor/ via eBay which looks to have a display exactly like our meter, which I know photographs well and is usually readable anyway if we can stick our heads into the cupboard.  They were very responsive on eBay and have said it does have a reset / zero function for moving between appliances.

I thought Big Clive did a youtube video on various energy monitors, but haven't been able to find it.

I've got a feeling there was something about the electronics in many of the low-cost/unbranded ones essentially being the same but in different plastic cases and with slightly different buttons. It might have been someone else though.

Spoonie_Turtle

Section62 said:

Spoonie_Turtle said:

A bit left-field but I came across this one https://lowenergysupermarket.com/product/plug-in-energy-monitor/ via eBay which looks to have a display exactly like our meter, which I know photographs well and is usually readable anyway if we can stick our heads into the cupboard.  They were very responsive on eBay and have said it does have a reset / zero function for moving between appliances.

I thought Big Clive did a youtube video on various energy monitors, but haven't been able to find it.

I've got a feeling there was something about the electronics in many of the low-cost/unbranded ones essentially being the same but in different plastic cases and with slightly different buttons. It might have been someone else though.

Interesting, I will have a look at his channel, thank you.

Section62

Spoonie_Turtle said:

Section62 said:

Spoonie_Turtle said:

A bit left-field but I came across this one https://lowenergysupermarket.com/product/plug-in-energy-monitor/ via eBay which looks to have a display exactly like our meter, which I know photographs well and is usually readable anyway if we can stick our heads into the cupboard.  They were very responsive on eBay and have said it does have a reset / zero function for moving between appliances.

I thought Big Clive did a youtube video on various energy monitors, but haven't been able to find it.

I've got a feeling there was something about the electronics in many of the low-cost/unbranded ones essentially being the same but in different plastic cases and with slightly different buttons. It might have been someone else though.

Interesting, I will have a look at his channel, thank you.

Found it, it was a teardown of one model, but there are comparisons with other makes/models/marks in the comments.

https://www.youtube.com/watch?v=fRGKilvExMo

Astria

Section62 said:

I wasn't commenting on the availability of 3.3kW rated kettles, only that 3.1kW isn't an 'absolute maximum'.

But in a way it is, because you can't find a kettle in excess of 3kW, yes, a 3kW kettle might draw more than that at startup, but it won't be quoted as that.

Likewise, a piece of test equipment may well have a 3kW rated limit, but it doesn't mean it'll malfunction if pushed slightly over that for a short period of time, in fact it's typically tested to ensure that doesn't happen. At work we even have a test bed for that exact reason with the text "Must accept current of at least 10% over quoted range and still be functional, must accept 20% over quoted range indefinitely although the unit may stop operating but must not be damaged and must return to normal operation when under this limit, must accept 25% over quoted range for at least 10 seconds without damage.".