Upgrading to the Multiplus II 12-3000-120 inverter in my travel trailer.
The NM-B 6-3 cable(7 strands per conductor) seems pretty stiff to make a solid contact in the spring terminals. Is this a problem with these new spring terminals. Should I use a wire with a finer strand?
I would. In my Multi Compact, I was not able to get 10/2wG Romex (solid) into the cabling area. On this model, a removable cover has the cable strain reliefs and it's necessary to flex the wires after connection. No go with #10 solid. Ended up with SJOOW which is stranded.
The Multi II has a different design so it may be possible to secure #6 NM-B wires into the contacts but if you have the option to switch to finer stranded wire I would.
I have this exact configuration. It was very difficult to get the wires into the connectors, and one of them didn't make good connection the first time. Everything was working when I tested it, but I also used a laser temperature gun to check the connections...and one of the hot leads was warming up. Because the conductors are in a cable, I had to redo all the connections and am very glad I did. I really don't like these push-in connectors. Push-in connectors are fine on a regular household outlet you can hold in your hand and tug the wires, but not being able to visually inspect the actual connection on something big like a Multi is a safety hazard.
After redoing the connections and testing under load, all the connections remain very near the ambient temperature.
