Hi. I’m new around these parts so please be gentle.
I’m planning to order an emonPi2 and just wanted to ask the community to help fact-check my understanding of what I will need in order to achieve my goal.
I’m an avid Home Assistant user and already have sensor data available showing total energy consumed (via Glow Zigbee CAD connection to smart meter) as well as Solis PV related import/export data.
My incoming mains connection splits into 2 via henley blocks. 1 cable feeds the main house consumer unit and the other feeds a remote consumer unit located within a campsite business which is 200m+ away. You can see the cabling in this photo:
My goal is to measure how much energy the campsite business is using, as at the moment it’s difficult to know considering the main energy consumer is a 12kW heat pump system in the main house.
I plan to order an emonPi2: 6-Channel Energy Monitor, Raspberry Pi 4B (so I have option of using wired ethernet), emonVS voltage sensor and power supply 1-phase (UK plug). But how many CT clamps do I need? Is 1x 100A CT sufficient fitted to cable 1 in the photo, knowing that I can deduct the reading from an already-known total usage figure in Home Assistant to figure out the house/campsite split - or would it be better to get 2x 100A CTs - fitted to cables 1 & 2? Or is there any sense in ordering 3x 100A CTs to fit on cables 1, 2 & 3 - despite an existing CT being on cable 3 for the Solis hybrid inverter?
I hope that all makes sense and would welcome any feedback.
Welcome, Olie, to the OEM forum.
I presume first of all that you want your emonPi2 with the RPi 4B option - not a separate RPi 4B.
Just a single 100 A c.t. should be sufficient, but there will be a time delay between measurements from the emonPi and those fetched from somewhere else. If all you’re interested in are daily or weekly totals, that is unlikely to be a problem. But if you want the consumption down at the resolution of the emonPi - every 10 seconds - then for peace of mind I’d have a c.t. on cables 1 & 2 out of the Henley blocks. I see absolutely no need for 3 c.t’s. (If there was a difference, which there will be, albeit small, you’d worry about which to believe.)
Thanks for taking the time, Robert. Based on your reputation around these parts, I’m now confident enough to proceed and will order with 2x CTs.
you in the UK because that’s a highly illegal and unsafe configuration that would not be signed off under partP… your campsite supply config is also highly dangerous So which were not only dangering yourself but the public on the campsite also What a horrendous configuration
EDIT
I’ve been invited to provide an update to this post, for the purposes of enhancing the readability and the rationale from my comment. of course I’m happy to do this .
So the concern from me is the potential for a fire and health and safety risk presented by the line to your campsite (in quotes). I do not know what’s on the other end of the line however taking your word campsite at face value I would
envisage there to me campers or a site and consumers of electrical energy and I would expect there to be more than one indeed multiple individuals and multiple consumers The line looks like a standard tail let’s say 100 amp so 10 consumers each consuming 10 amps which is hardly anything clearly is a risk. furthermore we don’t know where the campsite is however you mentioned 300m … that sounds significantly more than what we call a lazy lazy loop which again it’s a risk and country to electrical standards.
I could go on
The only reason I intervened is because whilst putting yourself at risk which is your perogative you actually put other people at risk… people who may not be aware of what you’re doing, they’re not members of this forum , and the general laws of liability apply here … endangering their lives.
Electricity is not trifle it should not be in the hands of anyone that does not fully comprehend and understand what they are doing … not only to themselves but to the innocent others as well.
I’m not going to argue or debate to and fro posts on this thread. Only you know the truth I don’t know where you can take the actiona needed , or not… suffice to say this is my final word on the subject and I’ll leave it at that. Enough from me.
So, if the “campsite” cable runs 200 m underground, I would have put a separate MCB and a 100 mA RCD on there for protection and isolation, and I’d have used a 2-core */SWA/PVC cable and earthed the armour, but the isolator and the Henley blocks are sealed so the installation must have been signed off by somebody.
Do you know what is on the other end of that cable?
