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jacobbenko avatar image
jacobbenko asked

Overload Multiplus

I have a 3 x 5Kva Multi's programmed as 3phase. We are getting random overload warnings on different phases and occasional outages due to overload. None of the Multi’s are using more than 5Kw at time of warning. But the total of the 3 inverters is over 5kw when it seems to overload. I’ve updated to all the latest firmware on the CCGX and Multi’s. Since doing that I’m now getting “#1 Device Switched Off” notifications every few minutes


Any help is appreciated! img-2097.png

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warnings
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3 Answers
Jason - UK avatar image
Jason - UK answered ·

@Jacobbenko several things to check,

Is the Multiplus thottling back because it is too hot? Noted by the fan running. As an example, my Multiplus 5kva unit can mange 4.2kW output constant in the cupbaord where I have it located with the door open. If I shut the door, the air temperature rises above 40*C and the unit throttles down to 3.2kW. If your unit is already hot from having to supply a constant load previossly in a warm environment, it might be overloading because the unit is already too hot.

What is the DC voltage at the point of overload? Is there too much volt drop on the DC side when you apply a higher load to the Multiplus?

Is the system grid connected or off-grid?

Do you have any power limited set up? For example, I have my Multiplus limited to 6kW just to it doesnt try to meet the higher loads, and therefore the grid will make up the difference. I do this because of the temperature of the compartment my unit is installed in and the heat the Multiplus generates when trying to supply a high load.

Can you provide a link to your VRM portal so we can look at the other data to see if there is something else that stands out?

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jacobbenko avatar image jacobbenko commented ·

Thanks for you reply Jason. Sorry for being vague on the install. The install is off-grid with 12 x 2.5kw BYD batteries. I’ve inherited the system and trying to sort out small problems at the moment.


The inverters are mounted in open air on Western wall (afternoon sun in Australia), but the overloads seem to happen mostly on L1 but also happens on the other 2 phases. The DC voltage doesn’t look like it dips on the last overload warning.


Also noting the constant #1 Device Switched Off


Here is a link to the VRM Portal https://vrm.victronenergy.com/installation/18921/share/4e16b29d

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nickdb avatar image
nickdb answered ·

Error #1 is common if one phase is powering off due to overload.

You'd need to isolate the cause and the one should resolve the other.

Also, have you set VRM to log in 1 minute intervals? Even so, it is too slow to capture a momentary spike that could cause problems.

As mentioned above, try rule out heat contributing.

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jacobbenko avatar image jacobbenko commented ·
Thanks Nick.


I haven’t had any reports of power shutting off for it to be throwing that fault. The client is open to upsizing the inverters but I don’t want to spend unnecessary money if these are doing the job as is.


It could be a temp issue but I think it’s unlikely due to it happening during the middle of the night also

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nickdb avatar image nickdb ♦♦ jacobbenko commented ·

Check the inverter alert section in the GX, it will show if any phase had an issue at that moment.

Have a look here for reference:

https://www.victronenergy.com/live/ve.bus:ve.bus_error_codes#error_1_-_device_is_switched_off_because_one_of_the_other_phases_in_the_system_has_switched_off

You might also have a bad inverter but you would need to catch the LED states at the moment it occurs, which can be annoying.

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jacobbenko avatar image jacobbenko nickdb ♦♦ commented ·

Thanks. It currently doesn’t have any issue but is probably something you need to catch at the time I assume? I initially thought it could be a faulty inverter but I’m also getting overloads on the other 2 phases. Also, before I did the firmware upgrade the issue was still there but from memory #1 warning wasn’t showing up. Is that because of the firmware that this is how showing?


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img-2106.png (310.5 KiB)
nickdb avatar image nickdb ♦♦ jacobbenko commented ·
Shouldn't affect it.

Check your comms (RJ45) cables between the inverters and the GX. Make sure they are good.

Try keep them away from power cabling.

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jacobbenko avatar image jacobbenko nickdb ♦♦ commented ·
System is an hour and a half drives for me so can’t inspect VE.bus cables but from a photo they don’t look to bad for interference. Although I like the suggestion, I don’t think that is what’s causing the issue unfortunately
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Alexandra avatar image
Alexandra answered ·

@Jacobbenko

Power factor...

If your loads are not PF1 you cannot run a 5kw load on a MP5kva.

What it the power factor of the loads there? You will see see the volt amps for each phase.

Then you have inverter derating because of heat. They are rated at 25° C hotter means less power.

The truth is they are overloading. If it is heat derating the fix is active cooling like an air con. If power factor, either PF correction or larger inverters.

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Alexandra avatar image Alexandra ♦ commented ·

Another option might be to move some loads off the overloaded phase. It seems like L1 is working the hardest there.

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jacobbenko avatar image jacobbenko Alexandra ♦ commented ·
Thankyou. I might be able to spread the loads a bit better, h it the overloads are happening on all phases but mainly L1. Im happy to accept temp as an issue and get him to run some basic fans as a trial, but some of these OL are happening during early hours of the morning when temps are low.


I can’t seem to fine the section where it shows VA. Are you able to point me in the right direction?

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