We knew Enphase Envoy and Inverters are communicating using Power Line Carrier,

The Envoy IQ is using Line-to-Line Singal instead Envoy-S's Line-to-N/G Signal.

It is a huge difference, because Envoy IQ is generating Differential mode signal

and, OLD Envoy is generating Common mode signal

To filter the signal from my neighborhood (he has installed Solar System last summer, unfotunately, he & I under the same utility tranformer). To solve the cross domain traffic issue, I need to filter the differential mode signal.

I have installed RP230-30-10-S between IQ combiner busbar And Wire_to_load_center.

It is suggested for Envoy-S (Line-to-N/G) system. but, Double stage filter has a good filtering on DM signal. Especially, this model shows 60dB insertion loss on DM. so, I have expected, it will filter the signal.

Insertion Loss (dB) = 20 * log10 ( Unfiltered / Filtered)

60dB means, 20 * 3 = 1000/1, the signal should be filtered by 1/1000 at 150kHz

Even consider some decay at 100kHz, the filtering performance should be 1/100 or better.

Leakage current of this filter is 1.8mA, it is pretty high loss

https://www4.enphase.com/sites/default/files/Power_Line_Filter_Single-Phase_TechBrief.pdf?utm_source=community&utm_medium=answer_links&utm_campaign=internal_reference

but, envoy is showing ‘Communications from other Envoy(s) have been detected’ early morning. And it is disappearing till evening, and showing again.

I have installed GTX-2300-Y02 between Wire_from_envoy and Breaker_Load_Center

Insersion loss is around 20dB in common mode. there is no differential value.

I am expecting around 10dB minimum, but, the leakage current is 0.5mA,

Too expensive to use it,

https://www.mouser.com/ProductDetail/KEMET/GTX-2300-Y02?qs=yqaQSyyJnNgbwvs18djAZg%3D%3D

Load center and combiner has located as below

MI - Combiner - RP230 - GTX2300 - Critical Load Center - XW 6848 - Main Load Center - Grid

Unfutunately, it can not solve the issue,

the message come again and again ~ like a die hard ....

Wait a minitue, just thinking again,

New Envoy is Line-to-Line communication, so, I have to remove/block a differential mode signal,

it means, the common mode filter is not working.

• Envoy-S    same as Common Mode Signal
• Envoy-IQ   same as Differential Signal

If install Ferrite Core on L1/L2, yes, it should not working -.-, that is just for old Enovy ONLY. !!!!

GTX-2300, it is a typical single stage common filter, it is good on common noise, and, have some filter for differential mode noise, i feel, that is not strong enough.

and, RP230-30-10, It is double stage filter, it have 60dB insertion loss on DM at 150kHz.

Unfotunately, those filters can not block the signal and, my envoy still detect the other Envoy(s). 

BUT, I feel so strange,

(1) it is detected when early morning  - when MIs start to work

(2) it is detected when evening - when MIs stop to work

(3) sometime at evening

so, I have tried to check the noise level and filtering level using SA

it makes me so disappointed, because I can not detect any signal from outside for couple of hours.

I have checked my device again, turn-on Enovy and check the signal

My equiment can detect a communication signal which has been generating from my Envoy.

I can find a signal, and confirm the filtering even I can not find the exact level of filtering.

[SO, THERE IS A BASIC QUESTION]

How my Envoy detect the other Envoy(s) signal ?

How my Envoy detect the other Envoy(s) signal after 2 filters ? there is 60dB insertion loss. Is it possible to be detected ?

ANYWAY, most power line filter is designed to minimize the power loss using small capacitor.

It means, not strong enogh on DM filtering, BUT, can not explain the the message while low power mode. Because filter will lost the performance while higher current mode,

I have ordered Q-LCF-064-1P-1 to make sure,

Because it said, IQ compatible,

75W maximum loss (via the maximum current), should be under 1/16 at my appliaction.

anyway, around ~19Wh is so high power consumption 

75W x 1/16 & 4.15h = 19Wh per day (or 7.1kWh per year)

Maybe need to try for the DM mode noise

This is showing how cable has connected and where is the panel/inverter has installed on my roof.

This is an simple electric node diagram,

Pretty complex tree than my expectation,

When I have chance, I should clean-up and optimize the wire routing.

becuase I found so many duplicate path, and far routings.

(1) remove cap from top route (between 12-13)

(2) install cap on end of 07

(3) move jumper wire between bottom and middle route, on top - middle

(4) move JB-middle to JB-bottom

and then, Break #1 route will have 9 inverters (longest 6 node)

and, Breaker #2 route will have 6 inverters,

for this job, jumper cable should enought to jump from mid to top.

little doubt ...

Maybe need

    50' Q-cable

    2  female connector to make an extension cable

    1  terminator

    1  cap

    1  connector disassembly clip/jig

Actually, the best method is

    (1) make an extra route from bottom to JB

    (2) update JB

But, need enough wire clips ...... so many....

I am sharing a question on Enphase Community

https://community.enphase.com/s/question/0D53m00007P62ncCAB/grid-instability-issue-anyone-have-similar-issue-

It is a known issue, but, No one answer it. 

It is a FW of Inverter or Inverter's Problem, 

Due to this issue, can lost 2-4% Pure Production in System, 

Because eqch drop will affect 1.5% lost. 

// Contents //

I have bought Paid Manager service to check in detail, 

I just find any advice or idea who have experienced it before

This is 7d graph, you can see the green spike, that is the point of issue, 

I have checked in detail 

Before the trouble, everything looks no issue, 

BUT, if check DC current, there is an different story

DC current is not 0A, it is 0.59A with 40.34V DC voltage. 

micro inverter is not just shut-down, it is eating DC current, and temperature is going up

it is the temperature spike which has shown 7d graph. 

First issue has started on Aug 17, and it become more and frequently, 

Second issued inverter has started on Sep 2, and it become more and frequently. 

3 inverters are twice a day, and 2 inverters are once per 2-3 days. 

not sure, it will get worse or not. 

Any idea or advice about it ? 

ADD/EDIT: 

This issue has started on AUG/SEP 2021

and, getting worse - more frequently, 

Finally, it start to shutdown 3 times per inverter 

ADD/EDIT : Bad news, It is affect on actual production

If see the green line, can see a power down at noon (it is average of 3 zone, 4-6 inverters are showing issue at only one zone even installed all at same time)

three inverters are showing error at similar time around noon. 

it is power level using Production Meter Reading at Envoy every minute. 

yes, production rate is slowing down little bit at noon, 

It means, It is real Shut-down & No Production. 

ADD/EDIT : Is it really grid instability ? 

I am running my system using AC Coupling Mode, GRID voltage is 237V (20V lower than actual 

grid voltage), and much stable. i have add RP230-30-10 filter, and 5 ferrite ring on L1/2 to filter 

noise. The issue has not been improved at all, not worst or better, same.

i have 3 groups, the first string is, Group1-Group2-Junction-Envoy // 2nd string is Group3 - Junction - Envoy. No issue on 2nd string at all. Most of Group 1 show an issue, 1 out of 5 at group 2 shows an issue, 2-3 times per week.