D300S loud noise

Today I’ve received the D300S Drop Down module. It seems to work fine, but it makes a strange loud noise, if production is 400W and above.

It sounds like a high speed fan rotating in the case.

Is this sound normal behavior or an indication for malfunction?

@SteCol , I am very sorry for the inconvenience, given your description, this should be the D300S fan not running properly. You need to contact support to register a return for repairing.

What is your order number please? I can inform you of the customer support email address for the corresponding region.

even my D300S makes an annoying fan noise when charging over 400watt, also despite having 3kw of panels on the roof, it does not go beyond 600/700 watts of charging even in sunny days. (sorry 'English with google translator I write from Italy)

Hi @tonino

thanks for the feedback regarding the noise. I can live with it, because the device is in the basement.

I’ve connected 1 string of roof installation* (1.54 kWp) via D300S to EP500 Pro.

Maximum PV load power was 1210 Watt so far.

*11x 140 Wp modules in serial connection. (U(oc): 475 V, U(rated): 367 V, I(rated): 4,2 A)

so in the end you didn’t do the replacement as suggested by Bluetti? does your d300s get very hot? I have to keep it indoors and the fan noise is not pleasant

My D300S get’s only warm, may be around 30 °C with my basement at 16 °C.

It works fine, so I didn’t request “return for repair” for the time being.

last question: so the fan no longer makes noise? that is, does it activate sometimes or never? thank you

Fan makes noticeable noise at 400W and above. But it is not roaring. It sounds like a small high speed fan, as it was built in personal computers from 20 years ago.

thanks SteCol, it would be useful to know if other D300S have the same operation, that is the fan that activates from 400 watts and above

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question: is it possible to connect 2 D300S to an AC300 at the same time?

SteCol can you set up your Ac 300 when using the D300S as described in the manual?? DC1 and DC2 input Source ( Other ) and PV Parallel Enable ( ON) because this configuration does not work for me, my AC 300 if the Parallel Enable is ON does not allow me to set the DC1 and DC2 du Other but automatically switches to PV

my D300S broke, made 3/4 loud bangs and then green/yellow liquid came out not even 1 month after purchase

My DS300s work fine. I have two of them and get at least 2k output each when they aren’t fighting my Tigo DC optimizers. That said, they should have built-in arc-fault protection and not fight with my optimizers/RSS, which are required by US safety code. I had to spend $2000 on arc fault combiner boxes to comply with code.