Hello everyone!
I had a question about the wire gauge for the inverter input. I am building my cargo trailer into an RV and went with a 12V setup. Lynx Shunt and two Lynx Distributors, Dual MPPTs, Dual 30A Chargers and dual Phoenix 12/1200 inverters (one for a mini split, one for the remaining GFCI outlets).
What puzzles me is the wire size input for the Phoenix - it limits to 2 AWG. Is that enough for a 1200W inverter?
The Lynx Distributor allows up to 2/0 wire lug, so I was considering a 2/0 AWG to 2 AWG reducer to have a thicker wire, but none that I can find are UL listed. Plus, Victron suggests no ferrules and bare wire only in the input of the Phoenix, no ferrules or lugs. My wire run will be less than a foot from the Lynx Distributor to the two inverters, so very short. Still, I’m very apprehensive. This seems to be right on the edge of the limit in amperage/gauge, when considering the peak 2200W output, which could shoot well north of 160A.
Do any of you have a 1200W Phoenix? Were you comfortable using only 2 AWG wire on the 12V side of the Phoenix??? Does it heat up???
I want to convert this to an RV license plate, so I will need to pass an inspection and want to build this fully code-compliant and according to the NEC 125% rule, my inverter will run around 90A with a 13.2V LIFEPO4 battery, which is 113A margin. I’m reading that the 2 AWG wire is rated for 115A. So I’m literally right on the edge of compliance. Why would Victron design it like this and not allow a bigger wire to input. Even a 1/0 would help here.
2AWG (as long as it’s a proper high-strand copper or tinned copper DC cable) has an ampacity of 210A continuous outside an engine space, unbundled.
The 12/1200VA (not watt) inverter could only possibly pull between 89 to 120A realistically - so in terms of ampacity, yes 2AWG is more than sufficient. That will vary, however, if you’re running wires in engine spaces, bundled, or in other conditions which would affect their heat dissipation capabilities.
The peak output isn’t much of a concern, as that’s only sustainable for seconds and isn’t a continuous factor for consideration, but even then so long as you’re using the correct wire, is still well within the ampacity of 2AWG.
I think VA=W in DC current, but what is the W/VA ratio on the AC side? 90%? 80% I do not see this in the spec sheet.
How many Watts (RMS) can I realistically expect then from this inverter? My 9k BTU mini split will pull on average 650-700W and peak briefly @ 1100 during startup. Are you saying that I may not have a strong enough inverter and instead of keeping my two Phoenixes on separate circuits I should parallel and combine them into one circuit? I was not aware that was even possible as I do not see any ports to sync the phase between the two.
That’s correct, it isn’t possible with those - you’d need VE.Bus products to do that, like a couple of MultiPlus 12/1200s, or the larger Phoenix VE.Bus inverters.