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The manual suggests that wiring to my power distribution should be upgraded because of the power boost feature. However, the manual only addresses 50 amp services. I have a 30 amp RV, so…from what I can tell I should use 6AWG wire from the multiplus to the the power distribution panel, and then upgrade the breaker there to handle any additional load from the power boost feature. Is there any documentation about using power boost in a 30 amp camper?
Crazy, I just logged on looking for an answer to the same question, exact same situation. I will limit shore power to 30a, but it's not clear in the manual how much power assist will add. I have a victron 12/3000 120v inverter. The following is what is stated in the manual:
"With its PowerAssist feature the Multi can add up to 3kVA (that is 3000 / 230 = 13A) to the output during periods of peak power requirement. Together with a maximum input current of 50A this means that the output can supply up to 50 + 13 = 63A. ".
This looks like it might be a "cut and paste" typo from the 230v version of the multi, because 3000/230 doesn't make sense to me for a 120v unit. If the 12/3000 120v unit can also do power assist up to 3000kVA, wouldn't the calculation be 3000/120v = 25a of assist? That sounds pretty extreme though if it could pass through 50a and assist another 25a for a total of 75a. If limiting to shore power of 30a, that would mean output on AC1 of 55a, which I think would be fine with 6awg, but too much for 8awg. I'm not sure what the difference is between 3000kVA vs. 3000watts, so maybe I'm not thinking right on this and my math is flawed.
The main breaker in your distribution panel will trip if you pull more than 30 amps. This is no different than the situation without the inverter inserted in the shore power path. There is really no way to limit power assist other than reducing the AC input current limit.
With the 30 amp breaker in the distribution panel, 10/3 is fine between the Multi and the distribution panel.
The distribution panel is limited to 30 amps by the manufacturer so fitting a larger breaker risks meltdown/fire. The only way to safely use more power is to replace the distribution panel with a 50 amp model. It will have larger busbars. Then you'd need 6/3 from the Multi to the distribution panel.
Power management is part of the RV experience. There's never enough power to turn everything on at once. Some of this is done for you sometimes: turning on the microwave often turns off the electric fire place and/or the electric water heater element. Other things you just need to learn to do manually. And different power thresholds apply on shore power or while running off battery. Automatic power management in an RV (e.g. turn off the air conditioner compressor while making coffee) would be really slick but I don't know of any available system that does that.
Always use the recommended wiring size for the inverter or components being installed.
The power boost (I assume you are referring to power assist) uses battery/solar power to add to the incoming power for loads.
See this video for more information.
If you look on the Victron channel there is one with the title
Did you Know - How to add power to a limited shore power hook up
Watts/kVA. Look on kVA as max watts that can be drawn, depending on the type of load, watts is usually less. It's a 'feature' of AC.
My reading of power assist is inverter capacity plus AC in. Afik same for 120V.
Size the cables for the full current. Plenty of calculators on line. If there are breakers in your unit, check what they're rated at,
@tmartin000 you answered what I was really getting at. For the record, I'm not really interested in getting 50 amps. Two devices often does not exceed 30 amps, but it does often exceed the 80% of a 30 amp breaker. I will look further into my particular power distribution.
Who says that extra 50a wouldn't be less than 30 seconds and cause no harm? Likely (in my 30a RV, it would be only short durations....air conditioner and a 1 min coffee pot, most likely...I used 6/3 and do not feel short bouts of 50a use.
