Victron Phoenix 12/800 Overload Tripping at 600W Load

DIY
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1

I received a new Phoenix 12/800 inverter and am seeing overload trips when attempting to run a 600W oil radiator heater. The heater has two switches: one for 600W, one for 900W, and both can be on for 1500W. All testing is being done with only the 600W switch on.

VictronConnect shows around 1034 VA output and the AC voltage rises from 119V (idle) to 124V under load. A Kill A Watt meter connected to the inverter output shows around 680W at PF 1. The battery is an Eco-Worthy 12.8V 150Ah LiFePO4, monitored via the Overkill Solar app, which reports approximately 847W DC input during the test.

I tested the same heater on a Phoenix 48/1200, which runs it without issue. That inverter reports 622 VA and the DC side shows around 669W input.

I’m trying to understand why the 12/800 is tripping when the load appears well within spec. Would appreciate any thoughts or similar experiences.

2

It is rated 650W continuous at 25 degrees C and 560W at 40 degrees C. Taking into account derating, it is not a good combination. The 1038VA is also well over the 800VA specification.

3

Here is a screen capture of both inverters running the same heater at the same 600W seting:

Notice the difference in VA between the two and the difference in actual DC wattage being drawn from the batteries. Something is not right with the 12/800.

4

I doubt that there is anything wrong with the inverter, it is your understanding. The efficiency of an inverter falls as the output power increases relative to the units rating. Running 650W of load from ann 800VA unit is at the max continuous rated and will be at the lowest efficiency, say 80%.

Running a 650W load on a 1200VA unit of the same input voltage will be in the best operating range and have perhaps 90% efficiency.

In your comparator tests you are comparing a 12V small unit with a 48V larger unit. 48 V units are inherently more efficient because they are increasing the voltage by a factor of 2.2, the 12V unit is raising the voltage by a factor of 10.

This explains why you see a higher input power on the 12/800 than the 48/1200. Running a 650W load on a 12/800 is less than ideal.

5

Here are both running a 300W Load:

Had to post a playlist as it’s not letting me post more than two links a post.