Using Shelly Pro 3EM Before Main Distribution Panel to Monitor Total Apartment Consumption and Control Battery Infeed

[leon]

Hello everyone,

I am considering using the Shelly Pro 3EM in my apartment to better manage our energy consumption and integrate a battery storage system. I have a few questions about the feasibility and setup of this system and would appreciate any insights or experiences you might have.

We live in a 2-room apartment with an annual electricity consumption of around 1400 kWh. My goal is to install the Shelly Pro 3EM before the main distribution panel to track the total electricity usage of the entire apartment. I then want to use this data to control when and how much power to feed into the apartment from our battery storage system.

Here are my specific questions:

1. Installation Feasibility: Can the Shelly Pro 3EM be installed before the main distribution panel to monitor the total electricity consumption of the apartment? Are there any special considerations or challenges I should be aware of for this setup?

2. Capacity and Measurement: Given that the Shelly Pro 3EM can measure up to 120 A per phase, is this sufficient for tracking the entire apartment's electricity consumption? Our combined usage rarely exceeds this limit, but I would like to confirm this from others' experience.

3. Integration with Battery Storage: How effectively can the data from the Shelly Pro 3EM be used to automate the control of a battery storage system? I plan to use a Zendure SolarFlow battery to feed up to 800W into my apartment (the legal limit). It is compatible with the Shelly Pro 3EM but I am more of a software guy, so I am not sure how this would work. My imagination is the following: Apartment draws 50W constantly, this gets sent every second to the battery and it feeds 50W. I turn on the dish washer, consumption goes up, Shelly tracks this and informs the battery, it ups the power feed into the home.

4. General Advice and Best Practices: Are there any general tips, best practices, or potential pitfalls to be aware of when setting up this kind of system? I will hire a professional electrician for this of course but am I missing anything?

Thank you in advance for your help and advice!

Best regards,

Leon

[tvbshelly]

On 6/17/2024 at 3:49 PM, leon said:

2. Capacity and Measurement: Given that the Shelly Pro 3EM can measure up to 120 A per phase, is this sufficient for tracking the entire apartment's electricity consumption? Our combined usage rarely exceeds this limit, but I would like to confirm this from others' experience.

The 120A is definitely sufficient:
Depending on whether your electrical grid is 110 V or 230 V based, the calculation is slightly different, but 110V * 120A is 13.2 kilo watts aka 13,200 watts, 230V * 120A is 27,600 watts instantaneous power. You would never use that much power in a private house/apartment/etc. Normal electrical house connections are protected with 35A or 63A (example from Germany).
Your consumption is 1400 kWh per year = around 4 kWh per day. Assuming (which is absolutely unrealistic) that these 4 kWh are only consumed for exactly one hour (and the apartment consumes nothing for the remaining 23 hours), that is 4000 W / 110 V = 36 A or 17 A (230V), i.e. much less than the 120A that the Shelly can handle.

[tvbshelly]

On 6/17/2024 at 3:49 PM, leon said:

1. Installation Feasibility: Can the Shelly Pro 3EM be installed before the main distribution panel to monitor the total electricity consumption of the apartment? Are there any special considerations or challenges I should be aware of for this setup?

Yes, you can. It is permitted as long as it is installed behind the electricity meter (behind from the point of view of the grid).

The local regulations must of course be observed. In Germany, for example, such an installation may only be carried out by a trained electrician. From a purely technical point of view, such an installation is not complicated.

The only requirement is that you connect the 3 phases correctly to the shelly, i.e. L1 to LA and the current transformer for L1 (which is around L1) to IA, L2 to LB and current transformer L2 to IB etc.