TL4000 high pitched whining

[siliconskum]

I'm not an electrcian or PV installer, so take what I say with a pinch of salt... But the cause of the whine noise is the PWM frequency of the FET switching has droped below 20+Khz into the audible range (at a guess, around 10 to 15Hkz). There are a number of reasons why this could happen, but I know nothing of the inverter you have, so I won't attempt a guess.

Sounds to me like the inverter is not happy with something. Typically this could happen with an inverter that is heavily loaded or running with a voltage outside of it's intended nominal range. As I said, I don't know about your inverter or the way your PV install is setup, so I cannot comment on what the problem is. I can only tell you what the noise is from...

SS

 

[kevineaton]

hi guys hope you are well. sorry for the delay, its takne time to get things sorted out here.

ok, have had a new inverter - no difference.

now they have out the original inverter back in and instead of having 1 string of 16 panels, i have 2 strings of 8.

the noise is now bearable.

however, today must be the sunniest day of the year, and i am only getting 3kw PAC. same yesterday. super sunny.

before it was changed, i regualrly got pac of up to 4 kw.

is there any way changing the number of strings like this could have effected that?

 

[SolarCity]

I think you will find it is more likely to be the hot weather that is causing the loss in yield. Very few systems will reach peak at the moment.

 

[kevineaton]

thanks for this...maybe i should get the hose on them.....??!

 

[SolarCity]

Definitely. Give it a blast and see if it makes a difference. You'll be surprised.

 

[kevineaton]

ok, i'll get the hose on the inverter in a mo

 

[FB.]

thanks for this...maybe i should get the hose on them.....??!

As a former scientist, I've had many instances of cold liquids coming into contact with hot glass.

Hot glass plus cold water = risk of shattering due to sudden, large, change in temperature (ever seen the end of "Alien 3"?).

If it doesn't shatter because it's some kind of heat-resistant, toughened glass, it may still, over time, gradually cause fatigue.

If the cooling was started early in the day, the glass on the panels would not have a chance to get so hot, therefore less temperature shock.

 

[SolarCity]

As a former scientist, I've had many instances of cold liquids coming into contact with hot glass.

Hot glass plus cold water = risk of shattering due to sudden, large, change in temperature (ever seen the end of "Alien 3"?).

If it doesn't shatter because it's some kind of heat-resistant, toughened glass, it may still, over time, gradually cause fatigue.

If the cooling was started early in the day, the glass on the panels would not have a chance to get so hot, therefore less temperature shock.

True enough, but is the cooling effect from the water not slow enough that it shouldn't cause an issue?

I would hope this would be the case or we'd have problem every time it rains on a hot day.

 

[kevineaton]

the water temp is probably 15 degrees, temp of panel cant be much more than 40 - cant see it being a problem, but you are right, it might cause probs.

i was only joking about spraying the inverter by the way (no-one bit! damn!)

 

[FB.]

True enough, but is the cooling effect from the water not slow enough that it shouldn't cause an issue?

I would hope this would be the case or we'd have problem every time it rains on a hot day.

Rain tends to be much less intense than a drenching from a hosepipe, so would cool the panels more slowly (i.e. over a period of a minute or two, rather than in a second or two as with the torrent from a hosepipe).
But, as you say: there will be occasions where it's hot and sunny and then the heavens open (Wimbledon?). I suspect that solar panels have some temperature tolerance, but, as with many things in life: they will only withstand it so many times before fatigue takes its toll and random chance is not on your side.

If you are familiar with the American Civil War, you'll note that they sometimes used increased gunpowder charges in their smoothbore guns to increase the range and hitting power. The first few times they did this, they'd usually get away with it (although some makes of gun would tolerate it better than others), but repeated firing of a particular gun with an increased powder charge would gradually take its toll until the gun's structural integrity was sufficiently weakened that it blew up in someone's face.

I suspect solar panels will be similar; they'll take some abuse, but each bit of abuse gradually takes its toll.

 

[pwboston]

The other problem where i live, you might get a better yield from the panels by cooling them down, but using a hosepipe will land me with a £1000 fine:28:

So, ill let nature take its course

 

[FB.]

the water temp is probably 15 degrees, temp of panel cant be much more than 40 - cant see it being a problem, but you are right, it might cause probs.

i was only joking about spraying the inverter by the way (no-one bit! damn!)

My solar panels were reaching 40'C in February when it was about 10'C outside (i.e. about 30'C warmer than ambient temperature in weak sunshine).
In strong sunshine and hot weather, I wouldn't be surprised to see a solar panel in the UK reach 70'C or more. I've just set up a little experiment with a thermometer and will report back when it has had time to stabilise.

 

[SolarCity]

So, ill let nature take its course

Pair of ladders and a full bladder?

 

[Gary K]

thanks for this...maybe i should get the hose on them.....??!

Good Idea, you may get an extra 1/2 kw worth about 25p and more than likely get a hefty fine as you wave a hose around at height for all to see.

 

[FB.]

My solar panels were reaching 40'C in February when it was about 10'C outside (i.e. about 30'C warmer than ambient temperature in weak sunshine).
In strong sunshine and hot weather, I wouldn't be surprised to see a solar panel in the UK reach 70'C or more. I've just set up a little experiment with a thermometer and will report back when it has had time to stabilise.

Thermometer stablised around 50'C in early-summer, late-afternoon sun, so 70'C, perhaps even 80'C seems quite possible in mid-summer, mid-day sun.