SMA Sunny Boy SB1700 Solar Inverter

[nukie]

Hi,
Here's a few pictures of my german made SMA Sunny Boy SB1700 solar inverter. I am not an engineer nor a wizard so my description might be incorrect.



First of all, it's very sturdy and robust unit, no flimsy items here. Being outdoor for almost 2 years in the harsh Australian weather, the paint job is starting to show it's age. No rust attack yet. The front panel cover is secured with 4 stainless hex bolts.


The LCD display is a 16x2, it display various information such as total kW generated in a day(resets when nightfall), current kW, current panels voltage, etc. The display changes every few seconds, if you wish to advance faster to next display you simply knock on the panel.


Once the 4 hex bolts are removed, you can smell the electronics!! so I believe it is definitely IP65 rated. Inside is clean as new. The seal did a good job of insulating the electronics from the environment. After removing the Earth spade connector, I check the enclosure without the front panel, the metal case is very robust.


Here's all the electronics glory with the front panel removed. Yes I am idiot I didn't switch it off.
The system consist of a mainboard which is the switching section and a controller which sits on top of the mainboard. Notice some pins and connectors on the controller board, they are for optional plugin such as networking bluetooth connection.


A quick glance of the circuit board revealed that the conformal coating has been applied by hand.


Unfortunately it wasn't applied sufficiently or not all components are covered properly. So we rely on the IP65 rated enclosure to protect the components.


This is the only board not protected with conformal coating, I believe it's the switch end.


One of the four massive reservoir that supports the switching mosfets above


One of the four mosfet with slotted PCB


The four switching mosfet are mounted on a thick bar of aluminium


The thick bar of aluminium is mated to the huge external heatsink


And another huge MKP


Here we have some MOVs that protect the system from lightning, very interesting they stuck it in a socket for quick servicing


Here's one of an encapsulated toroid and a uncapsulated


What bugs me is the mains supply to the unit, the spade connector is way too close to a cap nearby


Such a well designed unit with a flaw? Okay lets hope the insulation of the cap will provide enough isolation... Btw these spade connectors are awesome. Unlike regular spade connectors, they are spring loaded makes it a breeze to remove!

[EEVblog]

Very nice!
But I can't get over the name, here in Oz this is a Sunny Boy!


Dave.

[tom66]

All in all, it looks like a well designed unit.

The main capacitors are Hitachi AIC series, very high reliability, very high ripple current.

[Yaksaredabomb]

What bugs me is the mains supply to the unit, the spade connector is way too close to a cap nearby

Such a well designed unit with a flaw? Okay lets hope the insulation of the cap will provide enough isolation... Btw these spade connectors are awesome. Unlike regular spade connectors, they are spring loaded makes it a breeze to remove!

The whole thing looks pretty interesting nukie; thanks for sharing.  I had never seen those type of spade connectors before.  I wonder if you could disconnect the brown wire and twist it 180 degrees so the lever is on the capacitor side, facing away from the blue wire.  It looks like that might provide a little more clearance to the capacitor if you are concerned about it.  On the other hand, maybe the lever sticks out further than it looks and it would be just as bad or worse.

Jacob

[T4P]

The translucent shrouding on the cap will do it's job. I have seen them used in high quality SMPS PSUs and i won't be afraid to use them either

[Yaksaredabomb]

The translucent shrouding on the cap will do it's job....

Ohhh.  For some reason it looked like shiny metal before, very nearly touching the female spade.  Now the shrouding/insulation is really obvious to me though, haha.  Nvm.   

[SeanB]

Those spade connectors are used in every airconditioner I have seen for connections. They can fail but are only going to do so if wet for years. Can be a pain to remove if you cannot get to the latch in deep recessed areas. They will handle 20A with 80A inrush currents.