4 ms·

Perhaps I'm in the wrong thread but there is no part of me that wants to DIY my own power electronics design. I've designed a few bucks and boosts professionall

Perhaps I'm in the wrong thread but there is no part of me that wants to DIY my own power electronics design. I've designed a few bucks and boosts professionally and chasing down those failure modes was a headache. Victron = solid hardware, openly-documented protocols, no cloud? Fahgettaboudit. (then again maybe someday I'll hit some wall with off the shelf MPPTs and find myself wanting to go down that rabbit hole lolol. but honestly AC coupling seems cleaner in terms of things like fault protection on longer runs - fault on a stiff mains circuit -> breaker will trip. Fault on a circuit where the current/power is intrinsically limited to what the solar panels can supply -> ???) I asked about the transfer switch / monitoring because I've looked at the same problem here, first with a generator now with solar. Incoming power service is on the complete opposite side of the house from where I really want the power handling gear. The manual two breaker thing is practical (for a generator at least), but not code compliant here (no positive lockout). I would think Victron would have an option for a remote transfer (/disconnect) switch, but I haven't really looked into it yet. It would still have to get the grid phase timing somehow to line them up before connecting, so something more than merely a dumb contactor.

jacquesm 8mo ago
> Incoming power service is on the complete opposite side of the house from where I really want the power handling gear. Same in my house. > It would still have to get the grid phase timing somehow to line them up before connecting, so something more than merely a dumb contactor. Then you'll want a synchronous one. They match phase before making the switch, which is one reason why it's nice if you use one tied to your inverter, which already has the capability to steer its phase to match the grid.
- mindslight 8mo ago
  Are synchronous transfer switches a common thing, especially for residential / light commercial? The only references I could find are for data centers and the like with massive diesel generators. There's also the question of how an independent transfer switch would steer the phase, but nudging a Victron inverter like one phase-nudges a conventional generator would probably work. But really an independent transfer switch wouldn't actually fully solve the problem - power at the main incoming service panel would still have to blip off-on for the downstream Victron to see the grid loss, disconnect from grid with the external transfer switch, disable anti-islanding, and then re-close the relay to backfeed up its own AC-IN. And even that would be a bit dodgy relative to proper certification for anti-islanding. What one really needs for this topology is to move both the contactor and the current sense normally in the Victron, to the location of the incoming service panel. Which is why I was wondering aloud if they had a solution to do this, and coordinate with the inverter to maintain export rules, phase matching, etc. I'm guessing the common answer is just run two sets of wires, as with generators.

jacquesm 8mo ago

> Incoming power service is on the complete opposite side of the house from where I really want the power handling gear. Same in my house. > It would still have to get the grid phase timing somehow to line them up before connecting, so something more than merely a dumb contactor. Then you'll want a synchronous one. They match phase before making the switch, which is one reason why it's nice if you use one tied to your inverter, which already has the capability to steer its phase to match the grid.

mindslight 8mo ago
Are synchronous transfer switches a common thing, especially for residential / light commercial? The only references I could find are for data centers and the like with massive diesel generators. There's also the question of how an independent transfer switch would steer the phase, but nudging a Victron inverter like one phase-nudges a conventional generator would probably work. But really an independent transfer switch wouldn't actually fully solve the problem - power at the main incoming service panel would still have to blip off-on for the downstream Victron to see the grid loss, disconnect from grid with the external transfer switch, disable anti-islanding, and then re-close the relay to backfeed up its own AC-IN. And even that would be a bit dodgy relative to proper certification for anti-islanding. What one really needs for this topology is to move both the contactor and the current sense normally in the Victron, to the location of the incoming service panel. Which is why I was wondering aloud if they had a solution to do this, and coordinate with the inverter to maintain export rules, phase matching, etc. I'm guessing the common answer is just run two sets of wires, as with generators.