Magnum 2812 Inverter

  • 08/02/2025 12:04 PM
    Quote
    Message # 13527572
    Steve Finch

    I have a 2014 Fleetwood Discovery with a Magnum 2812 Inverter that today on the inside panel is showing 70 amps on both legs for a total of 140 amp. Shore power is 2 phase 50 amps. Nothing is running other then the refrigerator. Add to that Magnum Inverters are not made any more as of Jan 2025.

    Yesterday the breaker on the grid power pole(50 amps), 50 amp breaker inside the RV coming in from the grid and three other 20 amp breakers all tripped at the same time.

    After I reset all of the breakers and power was restored I  heard a loud humming sound that was coming from the Magnum inverter. Indicator lights were OK and when I touched the 12 volt positive connecting to the inverter it was extremely hot. The negative was not as hot. The batteries this connects to are 3 Battleborn 270amp batteries. I tested the battery voltage for all three and they were at 12.9 or 13 volts. with the inverter charger turn off. With the inverter charger on it was at 13.5 volts. The panel inside the RV showed it charging at 134 amps, Bulk Charge. I turned the charger off and the 12 volt wires cooled off quickly.

    This morning I turned the charger back on and it displays 24 amp charge rate in float state. What is causing the hot wires while in bulk charge? I have lowered the charge rate but it did not change the rate it was charging. The 12 volt wire is 2 gauge.

    Another issue the came from yesterdays ordeal is all three AC units will not cool. When the AC is selected unit 1 starts the blower fan but the compressor does not start. Then unit 2 starts same result and then unit 3 starts again same results. These 3 units are the original Mach 3s that came with the RV. What should I check first for the cause, the units themself, the controller boxes over the drivers seat, or where should I start and look for what? 

    Being the units are so old and don't cool that well when they were working replacing them is my first thought. 

    Any thoughts are welcome.
  • 08/02/2025 1:31 PM
    Quote
    Reply # 13527586 on 13527572
    Anthony McCool (Administrator)

    The first thing I would do is ensure you are getting clean power to your RV. When was the last time you took sandpaper to your main power 50 Amp Cable? It makes a difference. After that I would check the transfer switch.

    For the 12v issue it may be time to replace the Converter. If it is over 5 years old, I would consider it.
  • 08/03/2025 6:26 AM
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    Reply # 13527744 on 13527572
    Steve Finch

    The inverter is 10 years old. So, yesterday I found 2 online stores that still had new Magnum 2812 so I order one express shipping. It should be here NLT Wednesday. The included picture shows the 70 amps. I turned off ever breaker except the main 50 amp and the readings did not change.

    The 50 amp plug's prongs are clean. I haven't done anything with the transfer switch, it does hum but it has done that since I owned the RV. Should that be replaced too?

    Also found the hot water heater does not work after this, running on propane now. My inverter really messed up things.


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  • 08/04/2025 12:17 PM
    Quote
    Reply # 13528111 on 13527572
    Steve Finch

    I have continued digging into this issue finding out more about the system. The breaker panel is from Precision Systems and the panel includes load shedding. Inside the breaker panel is the controller board that manages all of this. They are tricky in how they preform load shedding as it not controlled by turning off the respective breaker.

    I reached out to Precision Systems and the tech team determined I have a blown controller board so I have a new one coming in by Friday. It is an interesting system and I am fortunate that the display board has the configuration settings which can only be configured by the RV manufacturer and not the dealer or owner. Following very detailed steps should program the new control board, we will see. 

    And they too confirmed the inverter needed to be replaced first. I will post updates as this progresses forward in a hope to help anyone else caught up in this situation.