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sanchosk avatar image
sanchosk asked

Error 28 after spike current with MPPT 250/100

I have a setup of the MPPT250/100, connected to 3 parallel strings of 4 series panels, each 480W (44.5V/13.78A no load, 37.1V/12.95A MPPT).

The controller works OK for multiple weeks.

Today there was a crazy weather - cold, snowy day with melting snow and sudden very strong peaks of sun.

Even my other inverter from Fronius that should generate 10kW max generated 10.3kW at those peaks.

However, what happened with my Victron MPPT was that 2x in the day the unit reported Error #28.

The unit keeps on working, there is no visible damage or any degradation of output. During those events, the charging current exceeded 100A (unit reports 101A max) with peak of around 5305W (177V solar voltage).

I have 32A circuit breaker on the panels and it did trip once today, but in the morning, not during the 2 reported events of error #28.

Reading the manual, it tells the unit is probably faulty.

What exactly does the error #28 mean? The explanation in the documentation provides really little information.

Is anyone able to share more information about the error and perhaps consequences what can happen with the MPPT? Is there a possible fire risk or something similar I should know about?

MPPT Controllerserror
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3 Answers
Alexandra avatar image
Alexandra answered ·

@SanchoSK

The statement reads as possibly faulty if the problem persists. In your case they have started up and are producing. So is not classed as a persistent error until you keep getting the error. The power stage is when the mosfets are not able to start producing.

What you are experiencing is cloud edge effect (cold panels alot of sudden sun) so spikes are to be expected, the string design is important for that particularly paying attention to cold temp over performance.

We are a long way from the firmware the detection process was introduced in and the mppts have had a design change since then.

What HQ are they? And how old are they? If you have alot of your 5 years left, then wait and see.

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sanchosk answered ·

Thanks for the answer. I will try to update the firmware - does not offer any option like that in Cerbo, so I'll try the android Victron app to see if that works.
I am not sure how old the MPPT is, I bought it 2nd hand few months ago, it looked unopened before, so might be quite new.

But the old firmware suggests otherwise...

Would a serial number help in determining the real device age?

Not sure what "HQ" means, can you clarify, please?

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sanchosk answered ·

So, update - firmware updated to v3.15 successfully.

I now know what is the "HQ" - it's HQ2120CJEJT.

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nickdb avatar image nickdb ♦♦ commented ·
So that was manufactured in the 20th week of 2021. So you should have almost 2 years, or so of warranty remaining.
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Related Resources

MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

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