Sounds the classic makes

[finalman]

OK so on my first morning with the solar connected I've noticed the classic making cracking / pooping noises and am wondering is this normal?

No smells or smoke yet and classic cover is on so I cannot see if there were sparks or not, yet classic still going after half an hour so I assume not.

Didn't make them when there was no solar and only the battery connected.

We're at the end of winter in Australia yet the room temp was about 10 Deg C.

Wondering if is some kind of electric switching happening in the classic or heat expansion as the classic heats up for the day.

Should I be concerned?

[Vic]

Hi final..,

It is fairly difficult to describe noises ...

Early in the day, late in the day,   or at other times when the Sun intensity is quite dim,  the Input Relay will 'click'.  This allows the Classic to measure the amount of PV power available  --  it is trying to decide if there can be any measurable amount of power produced,  in excess of that which is required to run the Converter.   If there is too little power to produce some charge,  the Converter shuts off,  and the input relay switches to off  --  causing a second click.

If you watch the Vin,  and the output current or output power,  you can get an idea if this is what is happening.

When the Vin is near the battery voltage,  there is a small tone that is often emitted from the Classic.   Believe that this comes from the inductors inside the Classic.

Both of these conditions are quite normal for many/most MPPT CCs,  including Classics.

Does any of the above seem something like what you are noticing from the Classic?

Vic

[finalman]

Does any of the above seem something like what you are noticing from the Classic?

Vic

Yes I did notice between 1 and 0 input watts it did make the clicking and now that there's lots of watts it's stopped.