Victron-Isolated MPPT

[Bluedog225]

I think I generally understand the concept galvanic isolation as it related to the Victron MPPTs.

How is this isolation helpful in real life? That is, what benefit is there from isolating the photovoltaic electrical system from the battery system?

I’m trying to decide if the SmartSolar MPPT RS 450|100 the way to go.

Thanks

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-MPPT-RS-EN-.pdf

 

[Brucey]

I think I generally understand the concept galvanic isolation as it related to the Victron MPPTs.

How is this isolation helpful in real life? That is, what benefit is there from isolating the photovoltaic electrical system from the battery system?

I’m trying to decide if the SmartSolar MPPT RS 450|100 the way to go.

Thanks

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-MPPT-RS-EN-.pdf

I guess it's possible for an mppt to fail in a manner where the PV voltage goes to the batteries and destroys them. With the rs450 100 and 200 that's physically impossible.

Other niceties are two mppt trackers (4000W max each), (still 100A combined max output), can use real lugs for the battery connections. It also monitors isolation between the PV lines. Quiet fan cooling.

I am unnaturally fond of mine and always plotting on how to get a second. Would highly recommend if you have the budget and the space. But a 250/100 will give you same charging output with smaller parallel strings for probably close to half the price of the 450/100.

 

[Bluedog225]

Thanks Bruce. It is a nice unit.

I wonder if that MPPT failure mode ever happens. And if it did, would the bms on the SOK rack batteries protect them?

@HighTechLab

 

[HighTechLab]

Thanks Bruce. It is a nice unit.

I wonder if that MPPT failure mode ever happens. And if it did, would the bms on the SOK rack batteries protect them?

@HighTechLab

On a galvanically isolated controller, pv can't be dumped straight to battery. On some other brand X solar controller, if they did fail this way, the BMS may protect the battery to a point, but the likely event is that the DC bus will be at such a high voltage every device connected to it will certainly go up in smoke. Most of the DC input caps on these devices are 80V rated.

 

[Bluedog225]

On a galvanically isolated controller, pv can't be dumped straight to battery. On some other brand X solar controller, if they did fail this way, the BMS may protect the battery to a point, but the likely event is that the DC bus will be at such a high voltage every device connected to it will certainly go up in smoke. Most of the DC input caps on these devices are 80V rated.

That makes sense.

Have you ever heard of a Victron MPPT fail in this way? I’m trying to decide whether the extra expense of the isolated unit is worth it.

Thanks