I was toying with building a multi channel current logger[1] that could
be used to instrument multiple circuits.

Has anyone used one of these:

https://www.aliexpress.com/item/4000680462559.html

If so, do you have dimensions for it?

Just wondering how difficult it would be to get a bunch of them into a
(reasonably large) CU. The only size I can see mentioned is for the hole
is specced at 13mm across.

[1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
inputs, and a capability to post logs every few seconds to a SQL
database running elsewhere on the network. Capacity for 16 channels
should cover all the circuits in both my CUs.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

John Rumm <see.my.signature@nowhere.null> wrote:
>
> I was toying with building a multi channel current logger[1] that could
> be used to instrument multiple circuits.
>
> Has anyone used one of these:
>
> https://www.aliexpress.com/item/4000680462559.html
>
> If so, do you have dimensions for it?

Not that one specifically, but I have (somewhere) one of these:
https://www.farnell.com/datasheets/2150011.pdf
which is 51 x 44.5 x 36.5 mm if you include the protrusions.

Judging by the scale of the jack plug I imagine that one is similar.
.... ah, this has dimensions:
https://shop.openenergymonitor.com/100a-max-clip-on-current-sensor-ct/

> Just wondering how difficult it would be to get a bunch of them into a
> (reasonably large) CU. The only size I can see mentioned is for the hole
> is specced at 13mm across.

Probably doable. Or to tails outside.

> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
> inputs, and a capability to post logs every few seconds to a SQL
> database running elsewhere on the network. Capacity for 16 channels
> should cover all the circuits in both my CUs.

Worth having a poke around Openenergymonitor as you might find they already
make something to do what you want. Although 16 circuits might get a bit
much.

Theo

On 21/04/2022 20:46, Theo wrote:
> John Rumm <see.my.signature@nowhere.null> wrote:
>>
>> I was toying with building a multi channel current logger[1] that could
>> be used to instrument multiple circuits.
>>
>> Has anyone used one of these:
>>
>> https://www.aliexpress.com/item/4000680462559.html
>>
>> If so, do you have dimensions for it?
>
> Not that one specifically, but I have (somewhere) one of these:
> https://www.farnell.com/datasheets/2150011.pdf
> which is 51 x 44.5 x 36.5 mm if you include the protrusions.

> Judging by the scale of the jack plug I imagine that one is similar.
> ... ah, this has dimensions:
> https://shop.openenergymonitor.com/100a-max-clip-on-current-sensor-ct/

Ah, well spotted, 57mm long by the looks of it - so quite large... might
be able to get them in at an angle - and stagger the height of adjacent
ones.

(I quite like that they are fully enclosed and are available in a
voltage output version)

>> Just wondering how difficult it would be to get a bunch of them into a
>> (reasonably large) CU. The only size I can see mentioned is for the hole
>> is specced at 13mm across.
>
> Probably doable. Or to tails outside.

I wanted to be able to record each circuit in isolation really (or at
least a number of them)...

Although one on the tails may be handy since I have one tall RCBO that
there is unlikely to be space to clamp - so calculating that as total -
others might do it.

>> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
>> inputs, and a capability to post logs every few seconds to a SQL
>> database running elsewhere on the network. Capacity for 16 channels
>> should cover all the circuits in both my CUs.
>
> Worth having a poke around Openenergymonitor as you might find they already
> make something to do what you want. Although 16 circuits might get a bit
> much.

Yup I did have a look at that - they did not have any off the shelf
designs that did more than a small number of channels.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 21/04/2022 20:06, John Rumm wrote:
>
> I was toying with building a multi channel current logger[1] that could
> be used to instrument multiple circuits.
>
> Has anyone used one of these:
>
> https://www.aliexpress.com/item/4000680462559.html
>
> If so, do you have dimensions for it?
>
> Just wondering how difficult it would be to get a bunch of them into a
> (reasonably large) CU. The only size I can see mentioned is for the hole
> is specced at 13mm across.
>
>
> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
> inputs, and a capability to post logs every few seconds to a SQL
> database running elsewhere on the network. Capacity for 16 channels
> should cover all the circuits in both my CUs.
>

You could try https://shop.openenergymonitor.com/components/

On Thu, 21 Apr 2022 20:06:48 +0100, John Rumm wrote:

> I was toying with building a multi channel current logger[1] that could
> be used to instrument multiple circuits.
>
> Has anyone used one of these:
>
> https://www.aliexpress.com/item/4000680462559.html
>
> If so, do you have dimensions for it?
>
> Just wondering how difficult it would be to get a bunch of them into a
> (reasonably large) CU. The only size I can see mentioned is for the hole
> is specced at 13mm across.
>
>
> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
> inputs, and a capability to post logs every few seconds to a SQL
> database running elsewhere on the network. Capacity for 16 channels
> should cover all the circuits in both my CUs.

You could wind your own current pickup on individual wires and calibrate.

On 22/04/2022 08:43, Sysadmin wrote:
> On Thu, 21 Apr 2022 20:06:48 +0100, John Rumm wrote:
>
>> I was toying with building a multi channel current logger[1] that could
>> be used to instrument multiple circuits.
>>
>> Has anyone used one of these:
>>
>> https://www.aliexpress.com/item/4000680462559.html
>>
>> If so, do you have dimensions for it?
>>
>> Just wondering how difficult it would be to get a bunch of them into a
>> (reasonably large) CU. The only size I can see mentioned is for the hole
>> is specced at 13mm across.
>>
>>
>> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
>> inputs, and a capability to post logs every few seconds to a SQL
>> database running elsewhere on the network. Capacity for 16 channels
>> should cover all the circuits in both my CUs.
>
> You could wind your own current pickup on individual wires and calibrate.

The ration of turns would be key. Hardly any need to calibrate. The
concerns would be the core material, saturation, leakage and bandwidth
to catch a spiky waveform.

On 21/04/2022 20:06, John Rumm wrote:
>
> I was toying with building a multi channel current logger[1] that could
> be used to instrument multiple circuits.
>
> Has anyone used one of these:
>
> https://www.aliexpress.com/item/4000680462559.html
>
> If so, do you have dimensions for it?
>
> Just wondering how difficult it would be to get a bunch of them into a
> (reasonably large) CU. The only size I can see mentioned is for the hole
> is specced at 13mm across.
>
>
> [1] Perhaps an Arduino mega, with ethernet/wifi to get loads of analogue
> inputs, and a capability to post logs every few seconds to a SQL
> database running elsewhere on the network. Capacity for 16 channels
> should cover all the circuits in both my CUs.

You might find Rogowski coils convenient.

--
Cheers
Clive

Clive Arthur wrote:

> You might find Rogowski coils convenient.

They were one of the reasons given for the inaccurate readings by some meters in
that Dutch university study a few years ago ...

<https://www.beama.org.uk/news/beama-response-to-ieee-article-on-accuracy-of-dutch-electricity-meters.html>

Maybe the affected meters weren't using them properly?