Hello,
we have an existing Victron system with 5.5kw panels, 150|100 TR MPPT, 80kwh of storage and Multiplus 48v/5000/701. We are expanding the system with another 5.2kw of panels, another 150|100 TR into the system.
The addition will have another solar distribution board also. We understand that wiring sequence is to connect from the battery busbar to the new MPPT first. Make any adjustments in the Victron app and then connect from the new MPPT to the solar distribution board, then connect the new panels via the new solar distribution board.
My questions are as follows: Do we need to do a complete shut down to connect to the busbar, based on our photos? We know that we need to connect the negative first and then the positive. Can we drive a screw directly into each positive or negative busbar to make the new connection or do we need to undo the existing connections and stack the cable connectors? Advice in regard to the connection will be greatly appreciated.
It looks like the existing MPPT has the negative connected to the busbar, where I have circled it in red, and the positive goes to the top of the fuse on the left.
I am not sure what that gap is on the negative busbar, but you might be able to connect it to the rest of the bar with a bridge cable, leaving the main negative of the inverter with the battery connections. For the new MPPT, you can add a fuse like an ANL or MEGA fuse, then utilise the spare hole.
If you shut the system down and use the DC cutoff, everything on the positive side will be isolated.
Let me know what you figure out or need more help.
The gap in the negative busbar is a plastic bar that disrupts a connection from the left side of the bar.
We have bought a breaker switch of 63A to go between the new MPPT and the positive busbar connection as you indicated. Do we need a bigger breaker? I note that the other MPPT seems to only have a maximum output of 47.5A during full power. Perhaps I am reading that incorrectly.
When we do the the final connection we have decided to do a complete shut down by totally isolating the busbar connections, the solar distribution breakers and the emergency cutoff.
I am thinking we can undo the current Negative connection on the busbar and then place another connector at that point, would that be suitable? I think it should be ok but want to check.
Can we double stack the positive connections on the busbar as I think that hole does not have a good thread on it? Nor do we have a spare bolt to go into that hole, unless I can use one of the spare bolts on the negative terminal?
No, dont use a breaker, it will overheat and trip. A fuse is much better. If you use a 32mm cable, then you can get a 100A mega or ANL fuse with holder and put it next to the existing fuse holder. If that hole is no good, you can add the positive of the second MPPT to the fuse holder but you may need to upgrade the bridge to 70mm cable.
I am having a guess but that second piece of negative bus might be isolated so you can add a shunt. If you put a small bridge, you can use both of the holes for the MPPT negative connections.
The bus has been purposely designed for battery on one side and charge, discharge on the other side.
