MN15 voltage output regulation

[dapdan]

All,

I finally got the MN15 installed by my client. I am getting reports from him that lights and fans are dipping in revolution and brightness. Anyone else had this issue. I am starting my investigation into this to resolve the issue. I have not reached out to Midnite as yet but intend to.

Damani

[FNG]

Dapdan,
This is not something we have seen for sure, the voltage regulation has been rock solid on these even with large loads coming and going.

Is this off grid or grid connected?

[dapdan]

FNG,

It is offgrid with grid input as a backup. I spoke to Rick this afternoon and I am to finish the remote wifi connection and take some installation pics and email to him. I will share my with the forum as I try to resolve this issue.

Damani

[mahendra]

All,

I finally got the MN15 installed by my client. I am getting reports from him that lights and fans are dipping in revolution and brightness. Anyone else had this issue. I am starting my investigation into this to resolve the issue. I have not reached out to Midnite as yet but intend to.

Damani

Might not be related but I would have come across this in several inverters .
When grid is connected I notice for most newer inverter like the one they try to match the grid which causes some of these issues.
I think this is true because our grid is not stable .

[dapdan]

Mahendra,

I think you hit the nail on the head right there. i asked the client to open the grid input breaker and so far he has noticed that it has stopped "dipping". Whilst I was setting it up I notice the inverter was indicating a high voltage input from the grid and I thought that was strange as our grid is stable and i never seen that from the scores of inverters that I have setup with grid input as a backup. So based on this I asked him to open the breaker. I will investigate and observe this further and report. I would be surprised that the allowable grid input voltage would be so sensitive that it would affect this advance inverter in this manner. This is why Midnite should have involved the forum community on the beta testing, you never know what would come up.

Forgot to mention our grid characteristic is identical to the US except that our frequency is 50Hz. Not sure if this would make a difference. Going to review the specs on the range of voltage and frequency inputs.

Damani

[dapdan]

All,

It has been at least two days since i open the grid input breaker and the inverter is behaving normally. It appears as though grid voltage hi, as percieved by the inverter, was the issue causing the variable output voltage and causing the lights and fans to dim and slow. Just for confirmation I will have the client close the breaker and see if it happens again today.

I review the manual and was unable to find any information relating to the acceptable voltage input range from the grid. I find this unusual for an inverter of this class range and cost. This inverter was suppose to be an upgrade from a growatt 6kW inverter from a signature, it does not feel like an upgrade at the moment. The growatt did not have this issue with output voltage regulation when it was supplied with the same grid input. It was a direct replacement without changing any part of the existing setup.

I would greatly appreciate any kind of fix for this issue with this inverter as it is highly unlikely that I will be able to alter the characteristics of the grid and because of the location of the setup in Barbados returning the inverter to the USA will be a nightmare and prove to be costly. I really need a remote fix maybe by firmware ideally.

Damani

[mahendra]

All,

It has been at least two days since i open the grid input breaker and the inverter is behaving normally. It appears as though grid voltage hi, as percieved by the inverter, was the issue causing the variable output voltage and causing the lights and fans to dim and slow. Just for confirmation I will have the client close the breaker and see if it happens again today.

I review the manual and was unable to find any information relating to the acceptable voltage input range from the grid. I find this unusual for an inverter of this class range and cost. This inverter was suppose to be an upgrade from a growatt 6kW inverter from a signature, it does not feel like an upgrade at the moment. The growatt did not have this issue with output voltage regulation when it was supplied with the same grid input. It was a direct replacement without changing any part of the existing setup.

I would greatly appreciate any kind of fix for this issue with this inverter as it is highly unlikely that I will be able to alter the characteristics of the grid and because of the location of the setup in Barbados returning the inverter to the USA will be a nightmare and prove to be costly. I really need a remote fix maybe by firmware ideally.

Damani

Is there a Spd on the grid input ?
If not it would be good to put one.

A lot of inverters like the one ,such as as eg4 variants , Deye/SolArk, Magrevo,SNRE all have these grid input issues.
You did mention that it's 50hz vs the acceptable 60hz so I see that is your problem.
All the One is trying to is its job it's not a design flaw it's a power company issue.

I am sure the One has parameter where you can adjust the grid input parameters like adjusting the acceptable Hz but I would highly advise against it as this could kill the One.

This is one major reasons why we do Offgrid setups with these inverters .Power company wouldn't cover damages , Soxwe over panel, ensure enough batteries or just use a manual transfer when weather is really bad.

our investment and time is too precious

[mahendra]

Alternatively you should check the grid protocol on the One. We use mostly the "Custom" settings rather than something like US / Puerto Rico or CANADA.

Not sure what setting the One have.
Don't think there is any ones in Guyana as yet.

[DarkForestSolar]

I wonder if setting the grid up as a generator input rather than a grid input would help?  If it thinks its a grid input, it will run in parallel with it, which means the grid gets to set the voltage and frequency, even if it's running 100% on solar.  If it's set up so that it is a generator input, I think (not 100% sure though, maybe Midnite can chime in), you can have it ignore the grid except when batteries get low, and thus set it's own voltage and frequency.  Many older inverters that were set up to do high battery transfer (or low battery transfer -- same thing, opposite names depending on the manufacturer), would completely isolate from the grid when the batteries were full enough to not need it, but a lot of the newer ones run in parallel with the grid even if the batteries are full enough -- which can be better for handling surges higher than the inverter could handle alone or assisting a weak grid.  But it does mean that the loads are subject to potential variable grid voltage, which sounds like your case.  So figuring out how to trick it into going back to an older operating mode of isolating from the grid seems like a solution.

[dapdan]

Guys,

All interesting points. I have reached out to Midnite and provided the info that Rick has requested. I was also able to have the inverter registered so they could connect and review what is happening. I am satisfied to be guided by them.

I installed a couple of the DIY MN3024 with grid input and the first one will be two years in a couple of months and have not given any issues. This small cheap inverter has the same grid as a backup and switches over at a battery voltage set point and charges the battery and support the load until the battery voltage return to a certain value. This inverter at 3kw and running three apartments has never had any dipping lights or fans. I did not expect this from an inverter that is in a totally different class, and price, to the 16lbs DIY MN3024. I await Midnite advice and guidance on this matter.

Damani

[dapdan]

Midnite,

Any of the techs the deal with the MN15, if they review this chat please assist me with my issue. I have been trying to do it behind the scenes and I am not getting any response from midnite. I reached out to them more than a week ago and provided the info required. I call yesterday and left a message. I have not experienced this type of support previously. So if any official person in this forum can offer assistance I would be grateful. I need to complete the install for the client.

Damani

[FNG]

Midnite,

Any of the techs the deal with the MN15, if they review this chat please assist me with my issue. I have been trying to do it behind the scenes and I am not getting any response from midnite. I reached out to them more than a week ago and provided the info required. I call yesterday and left a message. I have not experienced this type of support previously. So if any official person in this forum can offer assistance I would be grateful. I need to complete the install for the client.

Damani

Can you email me a brief description and who you talked to? ryan@midnitesolar.com I will read the thread now also and see what I can assist with

[FNG]

Damani,
You have probably shared this info with the tech but can you assist me with a few questions:
1- How big or deep are the dips?
2- How far apart are they, is it a fast flicker or a slow brown out?
3- What work mode are you in?
4- How are you using the grid as backup (IE are you in self consumption style mode)

Lastly if you can email me the the serial # so I can look over the settings and system logs etc? ryan@midnitesolar.com

[dapdan]

Ryan,

I have emailed you with all the info requested.

Thanks again