Shelly pro 3EM seeking guidence

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Greetings, i am a HA user for a couple of months now, and brand new too this community, so hello folks :grinning:

i am seeking some guidence regarding my generated Shelly Pro 3EM values.
This tiny device drives me insane … atleast it feels like that.

Since 4 days i have installed and integrated a Shelly Pro 3EM where questionable values are generated. After running 4 days it appears that the measured results do not align with reality.

According to our antique power meter (messzähler) i have used 34 kWh in those last 4 days while the Shelly Pro 3EM has measured 23 kWh, and honestly i have no idea what is causing those differences :roll_eyes:

Now i am not an electrician, although something is odd here and perhaps one of you could give me some guidence in order too generate the correct values i seek:

  1. The voltage on those three Phases are not in the same range?
  2. The active power of L2 does not correspond with L1 & L3

The installation went quite smooth if you ask me, …there is this antique meter which delivers 3x63A and a seperate PE-block where N is hooked up with PE.

I bought 3 Legrand B6 switches where i Hooked up the Shelly Pro 3EM and those CT clamps are according to my understanding correct installed

Does anyone of you have some idea why:

  1. L2 is out of range compared to L1 & L3?
  2. Why shelly is measuring less then the analog meter

I hope i could receive some guidence from you, so this mistery can be resolved

HAC
HAC1460×1112 146 KB

2

Are the loads drawing electricity evenly spread amongst the three phases? As your demands change and added electrical devices are added, load balancing to make sure they are spread across the phases does not always happen. Some equipment such as HVAC may have heating on one phase, cooling on another, etc.

How are you billed? Peak demand, average?

Carefully inspect the numbers printed on the actual CT clamps. Are they identical? A different rating one (400A instead of 100A) may have slipped in the production line and is giving different readings.

Are all the connections tight and the right way round? You may have dislodged existing wiring when installing the new equipment. Check all, specially the Neutral link as that can cause strange behaviour if loose.

Do you have each of the CT clamps on the correct wire?

Obligatory electrical safety warning with live mains power here.

3

They all appear to be 230V nominal to my eye. What differences are you seeing that concern you?

Forgive me, I don’t know the wiring colors or typical power delivery type of your country. If you’re getting 3 phase power, then it’s entirely normal for them to not match and the difference would return on the neutral.