I recently purchased a new to me Toy Hauler. The previous owner installed:
- MultiPlus II
- Lynx Distributer
- MPPT 150 | 60
- ETC
So the issue is I keep tripping a 30 amp breaker on my Onan 5500 and I’d get an inverter overload error when I would:
- Run 2 ACs
- Run 1 AC with microwave
Possibly Separate issue but happened at the same time: Solar stopped generating current in the middle of the day. I have like 2 Volts but 0 current(amps).
If I watch the input and output to the MultiPlus on the Victron connect app, I can see a negative value for power under AC Input 2. This value will fluctuate from: -1, -3, and -30,465W….
First picture is in Inverter mode, no Generstor or shore power:
With my generator running (I typically boondock) the value of the AC input 2 will sit pretty steady at -1026W and jump up to the -30,465W for a second.
Notice the value in AC output 2 matches AC input 2, but ONLY when generator is running…. And I don’t even have the inverter wired for AC out 2?
Now I’ll add a picture of my connections on the MultiPlus
And here is a pic of the MPPT in the middle of the day…
Your generator is a single phase output. Even though it has L1 and L2 outputs, L1 and L2 are in phase. As such, the MP2 sees the input as single phase and ignores L2 input and passes L1 input through to L1 and L2 outputs. You are tripping the breaker because the entire load is being carried by one leg of the generator. A very common ‘fix’ for this problem is to bridge L1 and L2 of the generator output. Usually easiest to be done at the generator connection of the ATS. Then the entire output of the generator will be available to the MP2.
Edit to add: the random power readings on L2 as described is no concern. Seems to be a thing with these 2x120 units. I’ve installed a lot of them and they all do the same thing under similar scenarios.
Thanks. That’s good to know the random readings on L2 are normal.
I’ve read about combining L1 and L2 but the weird thing is I didn’t have this issue 2 weeks ago… I ran both ACs for over and hour and I was easily able to run 1 AC with microwave on…
If the ambient temperature is much warmer than it was a few weeks ago when you didn’t have these issues, then you were probably running close to the limit for the breaker. Power usage on the roof warts will be substantially higher as the temperature increases. I see as much as 200- 400 watt increase when the temp goes up.
I am not sure I can combine the legs or it seems they are already combined. In the transfer switch I have left side generator(I think) right side shore power(I know).
I only see 3 wires when it’s input into the transfer switch.
I think I see about 6 wires in the second picture before it hits that silver box(not sure what that is) which then drops it down to 3 wires that run to my converter then to the transfer switch.
Look on the inside of the lid, should be a wiring schematic showing which one is gen and shore. To verify you can start the genny and check with a vm by placing one probe on the white, and the other on either the black or the red. That is a 50amp transfer switch. Grounds are connected together via the bus bars. White is neutral and red/black are L1 and L2. You can bridge L1 and L2 for the genny by adding a jumper between the red and black on the genny side of the switch.
1 Like
Recommendations to jump the wires? The diameter of the clamp in the transfer switch is too narrow to fit another wire the same gauge in there.
I was thinking stripping the wire back and soldering the jumper on.
Thoughts?
I wouldn’t do that. I would probably disconnect the generator L1 and L2 and use a junction block to bond them, then run a short 6awg wire from the junction block to the L1 generator input. The lug on the 50 amp transfer switch should be able to accept the 6awg wire. I can’t tell in the picture which phase pulls in the transfer switch, so if it doesn’t pull in when you power up the generator you might have to swap phases.
