I ended up returning that particular 3EM.
Regardless of which sensor I used or the orientation of them, that phase B port always showed some negative value somehow.
The other was fine
Beiträge von jyavenard
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Hi.
I recently got 2 Shelly 3EM device, to monitor 6 circuits (one 3 phases).
All shellys current sensors are connected to their respective phase and voltage sensor. I've checked this multiple times to make sure this was correct (the manual BTW is incorrect, "K" must be the direction of the load, not L which needs to point to grid, made me waste hours to figure it out and re-connect everything in a very tight board).
Originally, both were showing the same problems on phase B: when there was close to no load on the circuit, it would show a small negative values (between -3W and -11W) and as soon as their was a power draw then it would read correctly.
After restarting one shelly and clicking on "Restore Factory Calibration (All Phases), things got fixed, and it properly showed 0W as expected. That was weird as I never did a calibration to start.
But for one, it always shows -3W when there's nothing (power factor is showing as negative), as soon as you start something, it goes back into the positive.
I'm 100% certain that the voltage input is on the same phase as the CT sensor, this sensor is marked as "B" though I doubt this make a difference, I connected it to "phase 2" (white)
In Australia, Phase 1 is Phase B (+120 degrees shift), blue
Phase 2 is Phase C (+240 degrees shift), white
Phase 3 is Phase A. red.
Interestingly, this shelly is always reading the voltage exactly 1V under what the other shelly is ready, on all 3 phases.
Any ideas what is going on and is that fixable in software?
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Please ask the producer.
wouldn't asking here for other people's experience the right place ? I asked one simple question.
If you don't know, why answer?
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for monitoring you should use a measurement Shelly (EM, 3EM) not an actor, which should switch something
.My mind.
they are significantly bigger and can't be installed within an existing GPO though.
In any case, why rate something 16A if it can't even do 15?
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Regardless of the total amount, the inverter's result is always 20-30Wh higher than the Shelly. No matter if the sum is 200Wh or 4kWh. The question is, which unit you trust
Well, they don't measure at the same point now do they?
There will be losses in the wiring from the inverter to the shelly, that's guaranteed regardless of the cable size.
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I got a Shelly 1PM installed behind a 15A power point that is used with a Tesla mobile charger. I'm located in Australia so 230V/50Hz country
Now the mobile charger will draw 15A continuously.
Despite the Shelly 1PM being rated 16A, it will go into overpower mode within 5 minutes.
the 1PM is supposed to be rated for 16A, so assuming I don't have a faulty unit it's a rather misleading ratings.
Has anyone used a Shelly 1PM to monitor such load? if it's a known issue with the 1PM, which shelly would handle 15A continuous draw?
Thanks in advance.
Jean-Yves
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So is the Shelly Plus 1PM accurate now when it comes to voltage and energy readings or will it never been fully accurate and requiring a hardware change?
In short: should I get a Shelly 1PM instead then? (not plus)