Solar Panel system making high pitched noise

[AntronX]

What model number are those surge protectors?

 

[sidraja999]

The inverter did throw errors a few days ago. DC input voltage exceed....even thought the DC voltage did not exceed the threshold. This was confirmed by Growatt tech support

Also, ARC fault.

I had solar panels from two manufacturers in the same string. I thought this might be causing the errors in the inverter so I removed and only have the same brand panels in the string. Today, no inverter error codes....just that noise. The noise appeared when I had the panels from different brands....I thought it was a distant lawn mower .

 

[sidraja999]

What model number are those surge protectors?

Mnspd-600 600V Surge Protector

 

[AntronX]

That noise is a square wave at around 1 kHz. Could be MPPT overcurrent protection (desaturation). May be internal fault.

 

[sidraja999]

I’m not familiar with what’s possible on CCA wrt controlling the TIGOs. Is there an off chance they can be configured to behave as pass through only?

I don't think so.

 

[sidraja999]

That noise is a square wave at around 1 kHz. Could be MPPT overcurrent protection (desaturation). May be internal fault.

So from the inverter? Any setting I should check?

 

[sidraja999]

I have Tigos on my ground mount and have never heard them make a noise with a Sol ark 15k. I would suspect your noise is interference coming up the line from the inverter. Likely the 20kHz switching frequency of the inverter.

Any settings in the inverter I should look into?

 

[zanydroid]

BTW you should be able to download a spectrum analyzer app for your phone to see how much energy is in which frequencies of that sound.

What are the panel specs?

 

[zanydroid]

(I don't think it's time yet to dig into settings, don't have complete picture yet of how this is configured).

The graph you shared from the Growatt, is that all PV combined or just this string?

 

[sidraja999]

BTW you should be able to download a spectrum analyzer app for your phone to see how much energy is in which frequencies of that sound.

What are the panel specs?

Attached is panel label.

 

[sidraja999]

(I don't think it's time yet to dig into settings, don't have complete picture yet of how this is configured).

The graph you shared from the Growatt, is that all PV combined or just this string?

All PV combined

 

[zanydroid]

Attached is panel label.

Those are within spec for one MPPT even if the TIGO decided to boost current by 33% for unknown reasons.

Are there TIGOs on the other two strings?

 

[sidraja999]

Those are within spec for one MPPT even if the TIGO decided to boost current by 33% for unknown reasons.

Are there TIGOs on the other two strings?

Yes. Every panel has a TIGO.

 

[timselectric]

No editing. It is just like it sounds. The sound is from the solar panels.

That would scare me enough to shut it down emidiatly.
I would check all connections for a good connection, And correct polarity wiring.
If nothing abnormal is found. Then start isolating different parts to find the source of the problem.
Could be the SPD's, optimizers, or even a shorted panel.

 

[sidraja999]

That would scare me enough to shut it down emidiatly.
I would check all connections for a good connection, And correct polarity wiring.
If nothing abnormal is found. Then start isolating different parts to find the source of the problem.
Could be the SPD's, optimizers, or even a shorted panel.

No errors in the inverter. If there was a ground or ARC fault then it would point to a loose connection. Polarity wiring issues also would throw an error.

The TIGO per panel chart shows all panels producing. No errors in the TIGO app also.

 

[zanydroid]

That would scare me enough to shut it down emidiatly.

Originally I thought with just the Emporia graph, that looks broken, but surely the sound can't be that bad.
After opening the sound file, I got kind of scared and TBH if this was my system I would have turned it off and only turned it back on after having a plan for testing it / actually making a change towards debugging. VS praying something better happens on the next startup.

If nothing abnormal is found. Then start isolating different parts to find the source of the problem.

Yup I was going to suggest isolating. Binary search (do half the array) at a time.

I can imagine a single optimizer doing something weird that infects the whole string & ever power stage in it

Yes. Every panel has a TIGO.

OK, so I think what this says is, your inverter works fine with TIGOs. So the problem is specific to the components in this string or this MPPT on the inverter.

 

[zanydroid]

No errors in the inverter. If there was a ground or ARC fault then it would point to a loose connection. Polarity wiring issues also would throw an error.

Right but that sound IMO is bad enough to be like the "smell test" situation for bad food. If the food label says it's not expired yet, but your nose wretches as soon as you open the package, will you eat it?

 

[AntronX]

Try reducing panel voltage by removing few panels from the circuit. If that does not help then bypass all tigos and connect panels direct to inverter pv input.

 

[sidraja999]

Right but that sound IMO is bad enough to be like the "smell test" situation for bad food. If the food label says it's not expired yet, but your nose wretches as soon as you open the package, will you eat it?

The sound appears near the panels and in the DC disconnect box. What could this mean?

 

[timselectric]

I would still double and triple check all connections.
I can't count how many times I found a wrong connection on the third round of checks.