Headless power meter (possibly multi-channel)

[Leif Neland]

I'd like to measure the power usage of dryer, washer, freezer etc at the meter box.
I already have a modbus meter for the heat, but have no room at the fusebox for an extra meter for each fuse "channel".

Is there a unit which can be placed inside the fusebox and take one and more current transformers, and talking modbus or wifi?

[sundberg84]

@Leif-Neland - I have seen clamps you can have around each wire - is that possible (not sure how accurate they are)?
I also have seen some DIN rail power meters depending on what kind of fusebox you have (not sure how safe they are).

I have not used any of these... but maybe you get some ahead with this info.

[zboblamont]

@Leif-Neland Highly unlikely to find a unit which can just squeeze in somewhere in the box, it would likley be in breach of electrical regulations for starters, and your insurers would have a get out of jail card if something went wrong.
CTs are easy enough to fit, but you then need to feed them to an external unit or units. Have you considered replacing or augmenting the existing box?
If it is a surface mounted box, it is only a matter of finding space adjacent.

[tbowmo]

I just found this one http://www.lk.dk/support/nyheder/powertag, which seems interesting..

Only problem is that it is probably closed source etc. So not possible to get data out of it for your own purpose..

Edit..

Just found out that the pricetag is huge.. (as in everything that comes from that company) :(

[Leif Neland]

@tbowmo They claim the meters can be connected to existing systems.
It would make no business sense to go to a secret protocol; no way would any plant accept to have to replace existing control systems.

[gohan]

Have you considered sonoff pow? Not really compact, but definitely cheaper than many other options

[wallyllama]

Open energy monitor is both a commercial product and open source hardware/software, they have pages on using ct clamps.

https://learn.openenergymonitor.org/electricity-monitoring/ct-sensors/introduction

There is also a commercial product that uses 2 ct clamps and technology derived from speech recognition to analyze the powrer signal to detect what devices are running and even when appliances are gettimg ready to fail. I'd probably own one of these, but I am allergic to clouds.