In case it is useful, the bogart SC 2030 self limits to 30 amps, so you can over panel if you want to.
For better or worse, it is a pwm type, so it will turn on earlier in with a lower panel voltage, but is not as good when the panel voltage is high.
It is limited to 12 / 24 volt systems. Might be able to run 36 volt.
How does a PWM SCC self-limit current?
Only up to 45A per the manual.
No idea, but it says it does (I didn't believe it, so I had to look it up):
Solar-panel peak current...........................Max 31A for full efficiency. May be safely used with panels up to 45A,however charging current will be reduced to protect charger
So the transistor can probably handle 45A, but not the heating of 45A continuous.
PWM to limit heatsink temperature, as well as to regulate voltage, is my guess. Resulting in reduced average current.
Likely lower average charge current than if some steady-state lower current. W(heating) = I^2R
But since Victron has multiple voltage output options. It appears that it has multiple options for overpaneling. As long as you never exceed the ISC hard limit.
Even something like their 150/45 can be overpanelled on a 48V system.
At 48V it has a max output of 2600 watts. Entering the details of a particular panel I use, I could build an array of 6240 watts. That would be 240% overpanelled.
Can do so on 12V as well... Could put that same array on a 12V system only outputting 650W... 960% overpanelled...
In my opinion it's not overpaneling, If you stay within its listed input specifications.So if a victron unit can handle more than twice the PV than it can output, it isn’t really limited? And in fact is over panel friendly.
Again assuming you stick to the published specs of VOC and ISC.
But it is overpanelling.In my opinion it's not overpaneling, If you stay within its listed input specifications.
But if others choose to call it that. That's entirely up to them.
The reason for the high allowed ISC. Is to work with the low minimum voltage requirement. ( Vbatt+5v)But it is overpanelling.
The limits are there to protect the SCC, not to specify the actual power the SCC can deliver @ specific system voltage.
For example, 100/20 != to 2000W PV
It's the V and I limit you have available to work within to fit the amount of PV necessery to get the power output rating an SCC can provide at specific system voltage.
You can overpanel regardless of system voltage, as long the SCC has enough Voc and Isc headroom to do so.
Honestly, it's great to see this topic getting more traction. Just a year a go this wasn't the case.
This can help people upgrade to or design a more productive system, panels are cheaper these days.
But if you have more PV Wattage than SCC can deliver at specific system voltage, it will have enough to exceed the I rating of the SCC but the SCC will only use what it can.The reason for the high allowed ISC. Is to work with the low minimum voltage requirement. ( Vbatt+5v)
That's a good thing. It allows for a wide range of PV combinations.
But as long as you don't exceed the amperage than it's designed for (which is only limited by the ISC). I wouldn't call it overpaneling.
Most other MPPT's have a set amperage limit that it will use. No matter what the voltage is.
Like my Growatt's. They will clip at 18a, no matter what voltage the array is configured for.
You are more than welcome to call it that, if you want.But if you have more PV Wattage than SCC can deliver at specific system voltage, it will have enough to exceed the I rating of the SCC but the SCC will only use what it can.
That's overpanelling, yes?
To reduce current requires impedance.
Linear regulator drops voltage and burns watts.
Switching regulator has an inductor; current ramps up over time, so switching on an off limits current (and relates to voltage conversion.)
PWM can't do either. So I don't believe it regulates current.
Max 45A array, it said.
Yes, it could measure current and PWM a calculated amount. But using temperature would be free, if it had temperature protection.
Most MPPT could take any size array. Even a battery (thousands of amps on tap.)
Fair enough.You are more than welcome to call it that, if you want.
I don't.
The reason for the high allowed ISC. Is to work with the low minimum voltage requirement. ( Vbatt+5v)
That's a good thing. It allows for a wide range of PV combinations.
But as long as you don't exceed the amperage than it's designed for (which is only limited by the ISC). I wouldn't call it overpaneling.
Most other MPPT's have a set amperage limit that it will use. No matter what the voltage is.
Like my Growatt's. They will clip at 18a, no matter what voltage the array is configured for.