Noisy Boysie avatar image
Noisy Boysie asked

Multiplus-II + ET112 + Current Transformer


I have recently switched from the CT to the ET112 and noticed something odd

I have a Multiplus-II 3kva + ESS + 140Ah 48v Li-Ion + Batrium BMS (CAN-Bus) + Cerbo GX + PV on ACin

Everything is working fine expect I have noted the following oddity

I was uing the CT and could see the MP2 quickly adjusting to the PV lows and spikes during cloud movment and demands on the ACin during normal operation mode, but since switching to the ET112 I was able to see the MP2 is now really very slow at adjusting the inverter power output and charging, so much so that I can see 1.8Kw export happening from the battery when the sun comes out for 5+ seconds and importing while charging due to the cloud covering up the sun, this is very odd becasue with the CT it was super quick to change and keep the grid at Zero import or export.

I think because the metering has been moved to the Cerbo GX this now has to tell the MP2 to adjust I just wasnt expecting it to be so poor at controlling it with such a slow delay

Everything is working fine just really slow, I'm not runnign anything extera or doing anything extra with the cerbo gx, it is however in superuser mode running v2.52 (came out the same day the cable arrived to pulg in the ET112 so unsure if its a v2.52 related or just expected behavoiur) and i have node red connected to it, no perf issues though and only 1 flow (your charge at night flow) connected to it. Top is not showing any processes that would slow this device down.

Is this expected behaviour when using a ET112 or any Grid meter?


Mark Boys

Multiplus-IIESSEnergy Meterct
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3 Answers
jgd-ess avatar image
jgd-ess answered ·


I'm getting the same behavior with 2 parallel multiplus II. With Clamp connected to master unit, I get wrong values on GX grid readings, with ET112 system takes more then 5 seconds to adjust.

Maybe we are getting protocol problems between ET112 and GX.

Some help could be great.


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Nicholas Herbst avatar image
Nicholas Herbst answered ·

We are experiencing the same thing on several installations involving the ET112 and a MultiPlus II in ESS configuration. The Current Transformer allows the system to maintain the grid set point far better than the ET112 energy meter.

Why is the ET112 refresh rate and communication (baud) rate so much worse than the current transformer?
Can this be resolved with firmware?

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gyrovague avatar image gyrovague commented ·

@Nicholas Herbst Did you ever find a solution for this? I'm running into the same problem kinda, and Conlog prepaid meter is resetting grid input because of it. Supposedly Landis&Gyr is a bit less sensitive, but sometimes I see several seconds of 1000+W back-feed leaking, so I'm not sure L&G will really resolve the problem either, the root cause is really this inability to respond quickly to the load changes I think.

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jgd-ess avatar image jgd-ess gyrovague commented ·
I gave up on controlling the zero injection with the ET112 and placed a CT connected to each of the Multiplus.
The ET112 was only used to count the production of the old Fronius IG30 that exists in the system.
1 Like 1 ·
pcbl avatar image pcbl jgd-ess commented ·
@JGD_ESS, did you mean you have now 2 CT sensors, one for each MP, does that resolve the incorrect readings on the GX device? I have exact same problem, that might be solved with your help. Thanks.
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palom170 avatar image
palom170 answered ·

You need to insert a 3,5mm jack in the slave unit, it is only for inhibit the sensor in the slave unit. Please only the jack without clamp.

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