How much load can Megarevo R8KLNA support

Hrschk · Aug 22, 2022

I have a new installation of Megarevo R8KLNA. I have 10.2kw of QCell 425watt panels ground mounted in 4 serial strings coming into the inverter. The system is off-grid. I have four 10kwh GSL 48v Lithium "powerwalls". I know there is a 12amp current limit for the inverter from each of the 4 strings, but being serial wired, they should deliver 10.2amp in a perfect situation.
Currently, when I try to run my clothes dryer, the inverter will shut down with an over current error. This has happened 4 times and each time, there is no other large appliance running. Typically, just fridge, freezer and maybe a few LED lights (sometimes not even that).
When it gives this error, it is never pulling from the batteries. Yesterday there was zero current being pulled from any of the 4 batteries.
I am able to restart the inverter and then it will handle the load and not give me the error again. But, every other time, when I start up the dryer, except for twice (which was ironically after dark, so it had to use battery power), it shuts down with an over current error.
Anyone else experience anything like this or have any insight? The GSL support staff points me to the Grid Output limits and tries to explain to me I can only run a load of 38.8amp, but I know this isn't true. And, I'm not on grid anyway. I've pulled 80amps at a time, using small appliances around the house.
Screenshot is of the 4 PVs at the time my clothes were drying, just after it shut down. It doesn't' look right, because it should be pulling more current from the panels than this, but this is about the most it ever pulls.

fromport · Sep 10, 2022

Hrschk said:
I have a new installation of Megarevo R8KLNA. I have 10.2kw of QCell 425watt panels ground mounted in 4 serial strings coming into the inverter. The system is off-grid. I have four 10kwh GSL 48v Lithium "powerwalls". I know there is a 12amp current limit for the inverter from each of the 4 strings, but being serial wired, they should deliver 10.2amp in a perfect situation.
Currently, when I try to run my clothes dryer, the inverter will shut down with an over current error. This has happened 4 times and each time, there is no other large appliance running. Typically, just fridge, freezer and maybe a few LED lights (sometimes not even that).
When it gives this error, it is never pulling from the batteries. Yesterday there was zero current being pulled from any of the 4 batteries.
I am able to restart the inverter and then it will handle the load and not give me the error again. But, every other time, when I start up the dryer, except for twice (which was ironically after dark, so it had to use battery power), it shuts down with an over current error.
Anyone else experience anything like this or have any insight? The GSL support staff points me to the Grid Output limits and tries to explain to me I can only run a load of 38.8amp, but I know this isn't true. And, I'm not on grid anyway. I've pulled 80amps at a time, using small appliances around the house.
Screenshot is of the 4 PVs at the time my clothes were drying, just after it shut down. It doesn't' look right, because it should be pulling more current from the panels than this, but this is about the most it ever pulls.

Next time you want to run the dryer, try this: switch off solar on the side of the unit so it will run off batteries at that time, then start your dryer and turn back on the PV switch.
I think that might work since the inverter will be able to draw the starting power _extra_ from the batteries.
When you try and start your dryer in the normal way, your batteries are charged, PV is used to provide the load.
I think the MR is not using (but should!!) the available buffer from battery power.

Btw: what version of the firmware are you running ?
Newer version might have that fixed.

Hrschk · Sep 10, 2022

fromport said:
Next time you want to run the dryer, try this: switch off solar on the side of the unit so it will run off batteries at that time, then start your dryer and turn back on the PV switch.
I think that might work since the inverter will be able to draw the starting power _extra_ from the batteries.
When you try and start your dryer in the normal way, your batteries are charged, PV is used to provide the load.
I think the MR is not using (but should!!) the available buffer from battery power.

Btw: what version of the firmware are you running ?
Newer version might have that fixed.

LCD Version：V1.03.11
CPU1 Software Version：V1.04.09
When I switch off solar, it typically will throw the breakers for my panels, which are quite a distance from the house, and then I have to go outside to flip them back on again, including taking a screw driver to open the combiner box. Not a great solution. I can try it once as a test, though.
MR doesn't seem to use battery power at all for anything if the PV is available. Very discouraging. I did get my answer about how much load though. If the load is 240v, then the max current is 36.6amp. I should be able to run my water heater and my dryer with no problem, but I can't. And, they ARE on different legs.
I don't have space to parallel two of these MRs, so I'm likely going to sell this and replace it with a 12kw hybrid inverter.

fromport · Sep 10, 2022

Hrschk said:
LCD Version：V1.03.11
CPU1 Software Version：V1.04.09

Duh, your firmware was in the screen shot. sorry about that.

Since we don't know anything about the changelogs, we don't know what is fixed in what firmware version.
There is a newer version available:
ARM: V1.03.12
DSP: V2.04.12

The version of the firmware that starts with 2 is imo the switch to parallel capable units.

You could try it and see it it works better/more like you expect it to do.

Hrschk said:
When I switch off solar, it typically will throw the breakers for my panels,

Huh?!
Why would that be?
You use the turn switch on the side of the unit above the RSD button ?
I have no parallel strings and I didn't use any breakers, i did use DC disconnects so i can work on individual strings without taking the whole system down.
What is the setup of your arrays ? how many in series, what is Impp ?
And your settings :
sys settings -> PV input <- what is it set to ?

Hrschk said:
which are quite a distance from the house, and then I have to go outside to flip them back on again, including taking a screw driver to open the combiner box. Not a great solution. I can try it once as a test, though.
MR doesn't seem to use battery power at all for anything if the PV is available.

I found out that once it is using a significant load from the batteries already, it is pretty good in handling extra load impulses on a single phase (so far)

Hrschk said:
Very discouraging. I did get my answer about how much load though. If the load is 240v, then the max current is 36.6amp.

Yeah, for a few seconds 8800 watt /240 volt = 36.6amps
My electric dryer has a resistive heating element and basically a very small inrush peak, except for the motor that turns the drum that starts at the same time. Mine is 5500 watt.

Hrschk said:
I should be able to run my water heater and my dryer with no problem, but I can't.

What are the wattages of those loads ?

Hrschk said:
And, they ARE on different legs.

?? your dryer should be on 240, as are most water heaters.

Hrschk said:
I don't have space to parallel two of these MRs, so I'm likely going to sell this and replace it with a 12kw hybrid inverter.

I know other people who have done the same and they are really happy with eg the sol-ark

Hrschk · Sep 11, 2022

fromport said:
Why would that be?

Sorry, I got confused. It's, of course, when I switch the batteries off, without turning off the PV, that the breakers are thrown.

fromport said:
What is the setup of your arrays ? how many in series, what is Impp ?

4 serial strings of approx 270v, each going through a Midnight Solar combiner box and then each directly into the MR.

fromport said:
And your settings :
sys settings -> PV input <- what is it set to ?

I don't remember right now I'll have to look later.

fromport said:
I found out that once it is using a significant load from the batteries already, it is pretty good in handling extra load impulses on a single phase (so far)

My dryer has no trouble starting up at all. It's when the water heater does a heating cycle while the dryer is running that I have issues.

fromport said:
What are the wattages of those loads ?

They're both approx 3000watts. The dryer, of course, depends on the heat setting. I never run it on the highest heat.

fromport said:
?? your dryer should be on 240, as are most water heaters.

But, my house electrical panel has two legs. some 240v is on one side of the panel, others are on the other. Each leg goes separately into the MR as either Load 1 or Load 2. The water heater is on one leg and the dryer is on the other. So, not overloading either Load 1 or Load 2 of the MR with current. This is what my "electrician" pointed out.............that it shouldn't be over current since they are on different legs. Was he wrong?

fromport said:
I know other people who have done the same and they are really happy with eg the sol-ark

I'm looking at the Huayu 12kw

fromport · Sep 11, 2022

Hrschk said:
Sorry, I got confused. It's, of course, when I switch the batteries off, without turning off the PV, that the breakers are thrown.

imo you should never turn the batteries off. the batteries are what is giving the inverter the ability to

Hrschk said:
4 serial strings of approx 270v, each going through a Midnight Solar combiner box and then each directly into the MR.

I would like some more info on this. It does not make sense and shouldn't happen.
you have 4 panels in series.
Can you share what brand/model the panels are ?
If you go through a combiner box, you are combining (parallel) multiple strings of panels together and that is where you have a breaker?
What size is the breaker (amps) ?
I currently am under the impression that the breaker that was installed doesn't have the correct value.

Hrschk said:
I don't remember right now I'll have to look later.

My dryer has no trouble starting up at all. It's when the water heater does a heating cycle while the dryer is running that I have issues.

They're both approx 3000watts. The dryer, of course, depends on the heat setting. I never run it on the highest heat.

There are certain devices out there there that basically are a relay that would prioritize loads.
In your case it would disable the warm water heater from turning on while the dryer is running.

So 3000+3000 = 6000 watt.
What is the load of the rest of the house ? fridges/freezers, AC of any kind ? computers?

Hrschk said:
But, my house electrical panel has two legs. some 240v is on one side of the panel, others are on the other.

That makes no sense.
If something uses 240 volt it is always on both legs.
Only 120 volt loads are connected to either one or the other leg.

Hrschk said:
Each leg goes separately into the MR as either Load 1 or Load 2. The water heater is on one leg and the dryer is on the other. So, not overloading either Load 1 or Load 2 of the MR with current. This is what my "electrician" pointed out.............that it shouldn't be over current since they are on different legs. Was he wrong?

I'm looking at the Huayu 12kw

Did your electrician by any chance provide you with a schematic diagram how things are hooked up ?
If not, some photos of the breakers in your panels would help.

Hrschk · Sep 11, 2022

fromport said:
imo you should never turn the batteries off. the batteries are what is giving the inverter the ability to

I would like some more info on this. It does not make sense and shouldn't happen.
you have 4 panels in series.

I have 6 panels in series x 4. I have a total of 24 Qcell 425 watt half cell panels

fromport said:
Can you share what brand/model the panels are ?
If you go through a combiner box, you are combining (parallel) multiple strings of panels together and that is where you have a breaker?

The combiner box was existing there from an installer who did everything wrong. We left it in place, but the only purpose it serves is to protect the wiring with the 15amp breakers for each string. there are 4 serial strings of 6 panels. they are NOT parallel'd coming into the house. There are 4 strings coming into the inverter.

fromport said:
What size is the breaker (amps) ?

15amp x 4......one for each string.

fromport said:
I currently am under the impression that the breaker that was installed doesn't have the correct value.

Each string of panels has approx 11amp

fromport said:
There are certain devices out there there that basically are a relay that would prioritize loads.
In your case it would disable the warm water heater from turning on while the dryer is running.

So 3000+3000 = 6000 watt.
What is the load of the rest of the house ? fridges/freezers, AC of any kind ? computers?

That makes no sense.
If something uses 240 volt it is always on both legs.
Only 120 volt loads are connected to either one or the other leg.

Did your electrician by any chance provide you with a schematic diagram how things are hooked up ?
If not, some photos of the breakers in your panels would help.

2 25amp breakers for HW, 2 30 amp breakers for the dryer. fridge and freezer always running. I do disconnect the hwh when the dryer is running, but get tired of doing that, especially when there is company in my home. they usually forget and then everything shuts down. My solution is to get a new inverter that is larger and can handle at least 50amps @ 240v. Then, I won't have an issue.

fromport · Sep 11, 2022

Hrschk said:
I have 6 panels in series x 4. I have a total of 24 Qcell 425 watt half cell panels

Ok,
if you have 6 panels in series , nothing paralleled you don't need breakers.

Hrschk said:
The combiner box was existing there from an installer who did everything wrong. We left it in place, but the only purpose it serves is to protect the wiring with the 15amp breakers for each string.

doesn't hurt since you can not work on the strings without shutting down your whole inverter.

When I looked for your panels I found these specs:

No matter what you do, given the fact the energy comes from the PV panels, not from the inverter,
those panels should not be able to trip a 15 amp breaker. They simply don't have enough power.
Next time you are out there, can you take a picture of the junction box with the breaker ?

Hrschk said:
there are 4 serial strings of 6 panels. they are NOT parallel'd coming into the house. There are 4 strings coming into the inverter.

thank you for explaining that.
So when you disconnect the batteries, all 4 string breakers trip at the same time?

Hrschk said:
15amp x 4......one for each string.
Each string of panels has approx 11amp

and thus it should be impossible to trip a 15 amp breaker. Total mystery (to me)

Hrschk said:
2 25amp breakers for HW, 2 30 amp breakers for the dryer. fridge and freezer always running. I do disconnect the hwh when the dryer is running, but get tired of doing that, especially when there is company in my home. they usually forget and then everything shuts down. My solution is to get a new inverter that is larger and can handle at least 50amps @ 240v. Then, I won't have an issue.

I hear you, but I am just trying to think along why this is happening?
Do you have your wifi hooked up ? do you have graphs from solarman ?

Hrschk · Sep 11, 2022

Hrschk said:
2 25amp breakers for HW, 2 30 amp breakers for the dryer. fridge and freezer always running. I do disconnect the hwh when the dryer is running, but get tired of doing that, especially when there is company in my home. they usually forget and then everything shuts down. My solution is to get a new inverter that is larger and can handle at least 50amps @ 240v. Then, I won't have an issue.

fromport said:
Ok,
if you have 6 panels in series , nothing paralleled you don't need breakers.

doesn't hurt since you can not work on the strings without shutting down your whole inverter.

When I looked for your panels I found these specs:

View attachment 111462
No matter what you do, given the fact the energy comes from the PV panels, not from the inverter,
those panels should not be able to trip a 15 amp breaker. They simply don't have enough power.
Next time you are out there, can you take a picture of the junction box with the breaker ?

thank you for explaining that.
So when you disconnect the batteries, all 4 string breakers trip at the same time?

and thus it should be impossible to trip a 15 amp breaker. Total mystery (to me)

I hear you, but I am just trying to think along why this is happening?
Do you have your wifi hooked up ? do you have graphs from solarman ?

Why are we concerned about my panels tripping the breaker? My issue is not that. My issue is that I can't run the appliances I want to run.

I do appreciate your help. But, I'm aware of my panels specs and how they are wired and the current they are bringing in. The breaker tripping was a one time thing when I followed the manufacturer's instructions for shutting down the system, which is wrong and should never be followed.

fromport · Sep 12, 2022

Hrschk said:
Why are we concerned about my panels tripping the breaker? My issue is not that. My issue is that I can't run the appliances I want to run.

In understand that, but that means something fishy is going on.
Your PV panels can not provide more than 11 amps.
They are protected with a 15 amp breaker.
the PV panels are the source of the power and flows to the inverter.
What on earth happens when you flip the battery breaker in order to trip the PV breakers !?
Would like to get to the bottom of that,

Hrschk said:
I do appreciate your help. But, I'm aware of my panels specs and how they are wired and the current they are bringing in. The breaker tripping was a one time thing when I followed the manufacturer's instructions for shutting down the system, which is wrong and should never be followed.

okay, will forget about that whole part.

The fact you have 4 x 10kWh batteries hooked up should provide more than plenty amps to run the 8800 watt tops peak without even using any PV power. Your problem is a mystery to me.

Hrschk · Sep 13, 2022

fromport said:
In understand that, but that means something fishy is going on.
Your PV panels can not provide more than 11 amps.
They are protected with a 15 amp breaker.
the PV panels are the source of the power and flows to the inverter.
What on earth happens when you flip the battery breaker in order to trip the PV breakers !?
Would like to get to the bottom of that,

okay, will forget about that whole part.

The fact you have 4 x 10kWh batteries hooked up should provide more than plenty amps to run the 8800 watt tops peak without even using any PV power. Your problem is a mystery to me.

8800 watts is 36.6 amps at 240v. It's not a mystery for me. It's just too small. The only way to make it work is to do some sort of work around. I would prefer not to do this. I agree there is something wonky on the PV side. But, the panel wiring/configuration has been checked out by a solar electrician, AFTER correcting the first guy's mess, and has been blessed as correctly set up. I never have troubles when the batteries are running and the one time that I did a load of laundry, after dark, with the HWH running, it did not shut down the inverter. But, I'm guessing it might be something in the inverter. I can upgrade to the latest firmware, but I still will want a larger inverter, especially coming into winter when my electric loads will be a bit more.

cmack · Sep 16, 2022

Load 2 is for 'unimportant' loads. The MR will shut that off when battery is not sufficient. All critical loads should be connected to Load 1.

Hrschk · Sep 16, 2022

cmack said:
Load 2 is for 'unimportant' loads. The MR will shut that off when battery is not sufficient. All critical loads should be connected to Load 1.

My batteries have never dropped below 85% SOC.

cmack · Sep 16, 2022

Hrschk said:
My batteries have never dropped below 85% SOC.

I'm not sure what the system defines as "sufficient". It could be linked to the off-grid DOD / return settings, but the manual is not clear. If your current DoD is 15% but you have a return DoD of 10%, the batteries would not start discharging until they are charged up to 90%.

Hrschk · Sep 16, 2022

cmack said:
I'm not sure what the system defines as "sufficient". It could be linked to the off-grid DOD / return settings, but the manual is not clear. If your current DoD is 15% but you have a return DoD of 10%, the batteries would not start discharging until they are charged up to 90%.

I'll check my settings, because I don't remember DoD right now. But, I do know that my batteries are currently at 85% and charging and I can turn off the PV and use my batteries as we speak. So, I don't think that is the problem. My dryer and HWH are both on Load 1, not 2.

Hrschk · Oct 15, 2022

fromport said:
Ok,
if you have 6 panels in series , nothing paralleled you don't need breakers.

doesn't hurt since you can not work on the strings without shutting down your whole inverter.

When I looked for your panels I found these specs:

View attachment 111462
No matter what you do, given the fact the energy comes from the PV panels, not from the inverter,
those panels should not be able to trip a 15 amp breaker. They simply don't have enough power.
Next time you are out there, can you take a picture of the junction box with the breaker ?

Just an update for you. I finally went out to the combiner box and checked the breakers. The guy invoiced me for 15amp breakers, but he installed 12amp breakers. In the documentation for the QCells, it states that the breakers need to be 20amp breakers. After confronting the installer and him calling me every name in the book and insisting I'm stupid and don't know what I'm talking about, he finally consented to come change the breakers out for 20amp (as spec'd by QCell) and not charge me for it. I asked for his mailing address, so I'm pretty sure he got the message I was about to take him to small claims court. This isn't the only thing he messed up. I had to spend $2k redoing all of the wiring from the breaker box into the inverter because he only pulled one string into the inverter and I couldn't run even a single 240v appliance.

Pale1290 · Dec 31, 2022

Hello. Is there someone who can help me and explain. My megarevo 8k brought this program from the factory and I turned it off so that it would not export. But it continues exporting even if the disable option is present. Is there something else I have to do to make it not export. Thanks in advance.

fromport · Dec 31, 2022

Pale1290 said:
Hello. Is there someone who can help me and explain. My megarevo 8k brought this program from the factory and I turned it off so that it would not export. But it continues exporting even if the disable option is present. Is there something else I have to do to make it not export. Thanks in advance.

Do you have graphs from powerman that shows how much it is exporting?
did you not mixup L1 & L2 with the CT's?

Pale1290 · Dec 31, 2022

I do not confuse them, they are written where the CTs go. The problem is that it keeps exporting to the grip even though the option is disabled

fromport · Dec 31, 2022

Pale1290 said:
I do not confuse them, they are written where the CTs go. The problem is that it keeps exporting to the grip even though the option is disabled

The numbers in your 2nd picture don't add up
If solar produces 6 watt, 27 watt goes to your battery, your house uses 831 watt, where does the 861 watt **TO** the grid come from ?

From the grid: 861 Watt
From PV 6 Watt
Total in: 867 Watt

Loads:
battery charging: 27 Watt
consumed 831 Watt
total out: 857 Watt

That looks more in balance...

Have you measured with a clamp on current meter to verify it is actually exporting to the grid?
At the moment it looks like the graphs can not be trusted

Pale1290 · Dec 31, 2022

fromport said:
The numbers in your 2nd picture don't add up
If solar produces 6 watt, 27 watt goes to your battery, your house uses 831 watt, where does the 861 watt **TO** the grid come from ?

From the grid: 861 Watt
From PV 6 Watt
Total in: 867 Watt

Loads:
battery charging: 27 Watt
consumed 831 Watt
total out: 857 Watt

That looks more in balance...

Have you measured with a clamp on current meter to verify it is actually exporting to the grid?
At the moment it looks like the graphs can not be trusted

I don't look at the graphs much. As they asked me, I gave it to them. I base myself on the physical, on the counter the numbers go backwards. And the multimeter.

Pale1290 · Dec 31, 2022

fromport said:
The numbers in your 2nd picture don't add up
If solar produces 6 watt, 27 watt goes to your battery, your house uses 831 watt, where does the 861 watt **TO** the grid come from ?

From the grid: 861 Watt
From PV 6 Watt
Total in: 867 Watt

Loads:
battery charging: 27 Watt
consumed 831 Watt
total out: 857 Watt

That looks more in balance...

Have you measured with a clamp on current meter to verify it is actually exporting to the grid?
At the moment it looks like the graphs can not be trusted

look at the arrows in figure 2

NCSolarGarage · Jan 4, 2023

Arrow shows TO the grid, but where does that power come from? It can't be coming from battery since power is going TO the battery. And it shows only 6w of solar.

Likewise, how can you be consuming 831w of load with no pv supply? Strange indeed!

What happens when you turn off your breaker TO the grid?

How much load can Megarevo R8KLNA support

Solar Enthusiast

Attachments

Solar Addict

Solar Enthusiast

Solar Addict

Solar Enthusiast

Solar Addict

Solar Enthusiast

Attachments

Solar Addict

Solar Enthusiast

Attachments

Solar Addict

Solar Enthusiast

New Member

Solar Enthusiast

New Member

Solar Enthusiast

Solar Enthusiast

New Member

Attachments

Solar Addict

New Member

Attachments

Solar Addict

New Member

New Member

13.2kW Off-Grid

Similar threads