SMA SB33000 TL HC strange startup/shut down

Neu hier Angemeldet: 09.01.2008 Beiträge: 3

I have a PV installation in Antwerp since september 2007 and have a question on the convertor. When it starts in the morning it switches several times power on/off until the solarpower is hi enough. Same happens in the evening when power go's down. Is this normal ?? I should expect a kind of deadband to prevent this ... it can not be good for the electronics is it ??
You can freely answer in German, I can read but not wright it !!

Forumsinventar Angemeldet: 09.11.2007 Beiträge: 1026

Hi Hobbymachine,

well, the electronics itself does not care but the relais may as they contain mechanical parts that move and thus have a mechanical wear.
Could you please tell us what brand of inverter you have?
Basicallly this behaviour is not uncommon, depending on the amount of tries.

Ciao

Retrerni

Forumsinventar Angemeldet: 10.11.2005 Beiträge: 2122

HI,

Yes, it is normal! No problem…! 

The capacitors in the Inverter will be load direct after sunrise when only 2- 5W are available from the generator.
If the min input tension (~125V) is reached, the uP in the inverters and all other circuits like communication starts to work. If all test are Ok, the inverter load his middle circuit, close the output relays how needs (compared to the other elements in the Inverter) more consummation. If the needed tension in the middle circuit cannot be reached, the inverter shut down. With deep irradiation or on sunrise/sunset, this can happened over a long period.

As simple as that… don’t care about…

Neu hier Angemeldet: 09.01.2008 Beiträge: 3

Thank you for fast answer. Type of invertor is in subject tittle.
If I understand well all electronics exept final stages are starting up but by lack of suffucient power close down again.
Would it be an improvement to instal an external lightdetector adjustable between 5-100 lux and having an adjustable hysteresis (deadband) to avoid this switching on and off ?
This could be installed in the 220vAC powerline and it would mean f.e. switching power on a little bit later than normal but not off anymore unless light drops down seriously. At that time convertor cuts off automaticely as is now. If it is NOT an improvement I can save the money !!

Verfasst am: 10.01.2008, 16:05

Hello Hobbymachine!

At this link you will find the user manual for the inverter. At page 18 to 30 is the descriptions of the different operating modes of the inverter.

http://download.sma.de/smaprosa/dateien/1348/SB_SMC-BEN073618.pdf

It is not an improvement to install a external lightdetector.

Best Regards from Germany

Forumsinventar Angemeldet: 23.03.2006 Beiträge: 3299

Hi hobbymachine

if you have an increased number of connections to the grid, thats not good for the lifespan of inverters relays. For that case you should set the Parameter "Upv-start" some Volts higher and try out if it gets better.

best regards

Klaus

Neu hier Angemeldet: 09.01.2008 Beiträge: 3

To Kai Hoe, thanks for the link but in this case there is no indication at all on the display, only when start occurs all 3 leds flash a whille.
To Boelckmoeller3, think you set me on the way because when I started reading the manual (linked pdf) I found as a discription :

Upv-Start :
The DC voltage required before the inverter begins feeding power into the grid.
This value is above the minimum MPP voltage which is required in
order to always guarantee safe connection to the grid, and to
minimize grid relay wear.
If, after disconnection from the grid, and in the absence of any
further faults, the inverter does not automatically reconnect to the
grid, this parameter can be decreased in small steps.
It must be noted, that if the value is set too low, this leads to an
increased number of connections to the grid, and thus to increased
wear of components.

So it is bad for the components !!

I will inform installer to change this parameter !! Thank you all !!
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