I want to push no more than 6.9A continuous through one of my circuits; Do I need an exactly-sized 7A breaker, or a slightly oversized 10A breaker to accommodate some startup surge current? I've got a Growatt SPF 5000 ES (outputs 220V euro) and a step-down transformer. The transformer's continuous rating is 1500W. If the transformer is 95% efficient, and the inverter outputs at 230V, that's 1,500W / 0.95 = 1,579W in / 230V = 6.9A. (Did I do that right?)
The load is a 34' class A RV minus the following items: Refrigerator (runs on propane), water heater (propane), 12V anything including lights (separate solar system), air con (heat pump on separate 220V circuit), furnace (using the heat pump), laptops (on the 12V system). No coffee pot.
So the load includes TVs, video games, DVD players, microwave, internet modem, router, cordless phone, medium-sized blender, small kitchen appliances such as InstaPot or dehydrator, small electronics/shaver/things like that. SOMETIMES the 55A 12V converter (about 850W with inefficiency) will be turned on if the 12V batteries run flat but usually it will be disconnected with a switch and the batteries charged from a separate solar charger.
If I go with the 7A will it trip any time an inductive load starts? I think no; It's slow-blow with inertia delay. Time-delay curve shows that a 2x surge causes a break in 10 seconds. That should cover most surges such as from the microwave.
If I go with the 10A will a large unexpected continuous load overheat the transformer? I think yes, since I cannot constantly police the family's energy usage. They might plug in a small electric space heater.
What do you think?
The load is a 34' class A RV minus the following items: Refrigerator (runs on propane), water heater (propane), 12V anything including lights (separate solar system), air con (heat pump on separate 220V circuit), furnace (using the heat pump), laptops (on the 12V system). No coffee pot.
So the load includes TVs, video games, DVD players, microwave, internet modem, router, cordless phone, medium-sized blender, small kitchen appliances such as InstaPot or dehydrator, small electronics/shaver/things like that. SOMETIMES the 55A 12V converter (about 850W with inefficiency) will be turned on if the 12V batteries run flat but usually it will be disconnected with a switch and the batteries charged from a separate solar charger.
If I go with the 7A will it trip any time an inductive load starts? I think no; It's slow-blow with inertia delay. Time-delay curve shows that a 2x surge causes a break in 10 seconds. That should cover most surges such as from the microwave.
If I go with the 10A will a large unexpected continuous load overheat the transformer? I think yes, since I cannot constantly police the family's energy usage. They might plug in a small electric space heater.
What do you think?