Connecting Victron MPPT to 1500 watt inverter

[PaintBrush]

I recently saw a video where the user connected the positive coming out of a 100/30 Victron MPPT, then a 40 amp breaker, to a 1500 watt inverter positive post that also had 2 AWG cables connected to one 100 amp 12 volt battery. This enabled him to run high peak voltage AC appliances like chop saws and air compressors off of one battery, as long as the sun was shining. This was different than most system configurations that I've seen.
Is this advisable as long as there is a breaker that's slightly larger than the MPPT rating? or should the solar DC always go into the battery, then to the inverter?

 

[Goboatingnow]

T

I recently saw a video where the user connected the positive coming out of a 100/30 Victron MPPT, then a 40 amp breaker, to a 1500 watt inverter positive post that also had 2 AWG cables connected to one 100 amp 12 volt battery. This enabled him to run high peak voltage AC appliances like chop saws and air compressors off of one battery, as long as the sun was shining. This was different than most system configurations that I've seen.
Is this advisable as long as there is a breaker that's slightly larger than the MPPT rating? or should the solar DC always go into the battery, then to the inverter?

The wiring makes no difference. The fact is the battery is running the invertor

 

[Charleswgibbs]

I recently saw a video where the user connected the positive coming out of a 100/30 Victron MPPT, then a 40 amp breaker, to a 1500 watt inverter positive post that also had 2 AWG cables connected to one 100 amp 12 volt battery. This enabled him to run high peak voltage AC appliances like chop saws and air compressors off of one battery, as long as the sun was shining. This was different than most system configurations that I've seen.
Is this advisable as long as there is a breaker that's slightly larger than the MPPT rating? or should the solar DC always go into the battery, then to the inverter?

That charge controller, at the absolute maximum, will output 30a. 30a @ 14v is only 420w. So you'll never get more than 420w from the charge controller directly, in the real world it will be even less than that.

So no way to run a 1500w inverter directly from the controller, like the previous poster said the battery is providing the difference. From the description it sounds like that person is basically using their inverter terminals as mini busbars. If you post the video we would know more.

 

[PaintBrush]

I cannot find the video.
Would this configuration work in a 24 volt system with 400 watts of PV going into a Victron 100/50 MPPT, then current going through a 60 amp breaker on the positive side then to a 2000 watt inverter positive terminal that's also connected (through 2 AWG wire with a 175 amp fuse) to a 24 volt 100 amp battery bank?
Would there be any advantage in doing that, instead of what I currently have: the PV 400 watt max current going into the 100/50 MPPT, then 60 amp breaker, into the 24 volt/ 100 amp battery bank where it gets regulated by a BMS before going out (again, through the 2 AWG wire with a 175 amp fuse) to the 2000 watt inverter?

 

[ianganderton]

2000W divided by 24V equals 83A

 

[PaintBrush]

2000W divided by 24V equals 83A

So my breaker after the MPPT is too low and needs to be around 90, and the 175A fuse is too high and will never blow? The surge limit on the inverter is 4000 watts; 4000 /24V would be 166.7A which is how I sized the 175A fuse.

 

[ianganderton]

So my breaker after the MPPT is too low and needs to be around 90?

If you are using one of those cheap black breakers they are junk. Use a fuse

The fuse protects the wire

For a 2000W 24V inverter you are looking at 100A rated cable and fuse for that

The best and most robust way to build you system is around a busbar. Attach the battery, solar controller and inverter to it with each cable fused for the cable

The only reason to use the load terminals on a SCC is to make use of the timers and low voltage protections available. They aren’t designed for high loads like inverters

 

[Charleswgibbs]

I cannot find the video.
Would this configuration work in a 24 volt system with 400 watts of PV going into a Victron 100/50 MPPT, then current going through a 60 amp breaker on the positive side then to a 2000 watt inverter positive terminal that's also connected (through 2 AWG wire with a 175 amp fuse) to a 24 volt 100 amp battery bank?
Would there be any advantage in doing that, instead of what I currently have: the PV 400 watt max current going into the 100/50 MPPT, then 60 amp breaker, into the 24 volt/ 100 amp battery bank where it gets regulated by a BMS before going out (again, through the 2 AWG wire with a 175 amp fuse) to the 2000 watt inverter?

I don't think there would be any advantage to this layout other than avoiding the use of busbars or too many lugs on a battery terminals.

If you have the charge controller, inverter, and battery all connected then the exact wiring configuration doesn't really change anything as far as how the power is used.

For example, if your panels are producing 400w and the inverter is drawing 300w, that 300w is already going directly from the controller to the inverter even if there is a battery in the circuit.

The whole 400w isn't getting sent into the battery, just whatever is available after the loads are satisfied. This will be true whether you wire everything to busbars, or wire everything to the battery, or daisy chain off the inverter.

Like the previous poster said using busbars is the most desirable setup, and definitely don't use the controller load terminals for an inverter.

 

[PaintBrush]

I didn't mention that the battery is fused (300a) between a shut-off switch and the positive post of battery; after the shut-off the current is going to a positive busbar; The MPPT positive (after a 60a breaker) is connected to the positive bussbar; off the +bussbar is a 50 amp breaker that then goes through a 24 volt Victron 'Battery Protect 100' before it goes into a 24 to 12 volt step-down 'buck-boost' converter. Then the 12V goes to a 12 volt DC distribution panel for 12 volt loads. I plan on having another 24 volt distribution panel after the Battery Protect but I don't yet need it. The idea is that running all the 24volt current through the Battery Protect, I can shut down all loads both 24 volt and 12 volt within seconds with the VictronConnect app. This does work. Right now, this 12 volt leg is turned off via the 50a breaker and the Battery Protect is off as well since I'm not running any 12 volt loads. Also coming off the positive bussbar is a quick-connect wire that I can connect to a 24 volt 8/16 amp output Victron Blue Smart Charger that I attach and charge the batteries when they are low, about every two weeks.

All the negatives go to a negative bussbar, then the -bussbar connects through a Victron 500a Smart Shunt before connecting to the negative of the battery. A quick connect wire also is coming off the -bussbar that can connect to the charger's negative. This system will eventually go into a van, but for now it's just running a residential refrigerator off the AC from the inverter.
And nothing has tripped or blown so far... even using my system to power a chop saw, and the large refrigerator (but not both at the same time).

I was just wondering if there was a more efficient/'best practice' way to set the system up.