FYI Generator AGS tested successfully

[Neal]

30amp may still be too high if you had additional loads such as air conditioning or other large draws. Tripping the breaker is unusual but does indicate a high load was present.

Was the oasis on by chance?

I disagree. It’s the max current the inverter can pull from the grid. It should be sized based on the supply; GEN or Pedestal.

 

[redbaron]

I disagree. It’s the max current the inverter can pull from the grid. It should be sized based on the supply; GEN or Pedestal.

Yes. So if you are pulling 30amp from generator for charger and 30 amp for ac, and 30 amp from oasis you easily flip a breaker.

I have run out of amps on summer days and had to dial down the charger to keep it from pulling the load. Silver leaf and normal ems will do this, but if the new charger is not part of the ems plan it doesn’t auto adjust based on max load per line.


The charger is directly connected to L1 only, so a 20amp load on L1 in addition to the charger will cause the generator to flip.

The breaker trips for either load, same as a pedestal.

 

[Joe Dutchstar]

Thinking about the AC load, if the KIB recognizes where the source is from it will shed the AC. I’ve had that happen. It gives an error##.
I’ll test that when the circumstances provide an opportunity.

 

[redbaron]

Thinking about the AC load, if the KIB recognizes where the source is from it will shed the AC. I’ve had that happen. It gives an error##.
I’ll test that when the circumstances provide an opportunity.

It would be good to see if it does recognize the load for the charger and can shed.

KIB usually doesn’t shed the charger, but rather sends it a message to change the rate in steps of 30/20/15/10/5

 

[Neal]

Not how I see it. I see it as max incoming from supply cannot exceed 30A. He has two inverters like I and each inverter has 30A set. So the coach has 60A available. If he used 50A as I had set then it exceeds the GEN breaker and trips it.

The EMS still shows 50A max for available loads. This cannot be exceeded otherwise loads shed.

 

[Neal]

Some Victron inverters have power assist like mine so if the loads are higher than the grid can supply then the batteries augment.

 

[redbaron]

2 inverters only make my point even clearer. This means both L1 and l2 have 30amp potential and 15amps anywhere else will trip the breaker.

Joe, this is where you should test. And also make sure that you are wired to L1 and L2. If both inverters are pulling on a single line then you will trip without any other loads.

You have a max of 45amp on each line, and continuous load of 80% of 45amp.

Remember this is a 10kva, so it can only provide 43amp surge and 80%continuous per line, and a total of 83 amp at sea level.

The 10Kw can easily get overloaded if not balanced.

66amps continuous rating is the standard, although I have run them at 70amp continuous with no issue.

A load for 10 minutes above 70amp could trip the breaker. A single line load over 35 amp could trip breaker.

 

[Neal]

Keep in mind it’s a 45A 2-pole breaker.

 

[redbaron]

Keep in mind it’s a 45A 2-pole breaker.

Of course. L1 and L2.

It also a max load of 10000volt amps

10000/120=83amps
83 * 80% =66.6amps

66/2=33amps for L1 and 33 amps for L2

This shows how you can easily overload that generator with 2 inverters and even the smallest of extra loads like a refrigerator, air, television, etc.

I would turn the inverter to 20amp when using generator.

You do have the ability to exceed the 80% recommendation, but then you are dealing with unknowns and require plenty of monitoring and testing to know what limits to expect.

Altitude, temperature and humidity all factor in to what available power can be drawn from the generator, so exceeding 80% comes with unknown results.

 

[Neal]

The moral here is know how to manage your loads. I'm staying with 30A on my inverters unless I have a problem. The first 22A I'll give up is OASIS electric elements and go burner only. If I need more power for loads I can easily turn off the charger from my phone through VRM or Bluetooth but putting the inverters in inverter only mode instead of ON.

Using 50A for input current in each inverter if on GEN will trip the breaker as I learned and people need to understand what these settings do and what the limits are of the grid (shore/gen).

 

[Joe Dutchstar]

Reading the posts and references to 2 pole breakers. So a 45 amp breaker, is that at 240 volts? Or 45 amps on each 120 volt leg? In other words either Leg 1 or Leg 2 is limited to 45amp? This starts to makes sense. 10kW at 240v is 42 amps. 42 amps on each leg. Leave some room for spikes and you get to a nice round 45 amp breaker.
Possibly I am missReading this?

 

[redbaron]

If you where to take power across L1 andL2 you would in fact see 240V, if the phases where out of phase.

In generators this is not guaranteed, and the power delivery of the Onan RV models is such that both kegs are in phase, and prevents you from actually getting 240v.

Instead what is created is 2 legs of 120V , with the combined rating equaling the generators specs.

The breaker is sized at 45amp, but the generator cannot make that much power for long. The breaker tripping means the generator became overloaded.

 

[redbaron]

I just looked at the specs and it appears the onan 10Kw can in fact deliver 240v. I have seen some that do not, but that may be the 7500 and below.

 

[osuallen]

You have a max of 45amp on each line, and continuous load of 80% of 45amp.

To clarify @redbarons point - in electrical circuit design you never design a circuit to be loaded no more than 80% of the breaker rating. Breaker design allows +/- 10% trip variability of the rated amperage amperage when new. If the breaker is tired, it may trip earlier. For example, a 20 amp breaker is allowed to trip anywhere between 18 and 22 amps. When hooked to 50 amp shore power, I set both of my Victron inverters to 40 amps max input. A couple of times, I have been in an old park where I have had to drop that all the way to 30 amps to keep from tripping the breaker.

 

[Neal]

Let's take a step back. Many of us, self included (guilty as charged) have Magnum on the brain. @Joe Hogan has Victron as do I. Modern inverters such as Victron are "smart" inverters and adjust charge rates, etc. as needed. The term "max charge rate" is a Magnum term, that is not present in Victron. Victron's inverter has you enter the shore current limit - i.e. what is the size of your input you're connected to. If connected to a 50A pedestal, this can be set to 50A, if GEN (for me) then 30A, if connected to a 120V/15A plug then 15A. It has nothing to do with charge rate. There is no setting for such that I can find via the Cerbo GX, I'd have to check the BMS, etc. via Bluetooth to see more settings available.

From the Victron manual, the charge rate is taken from the surplus after the loads are met:

PowerControl – maximum use of limited shore current The MultiPlus can supply a huge charging current. This implies heavy loading of the shore connection or generator set. Therefore a maximum current can be set. The MultiPlus then takes other power users into account, and only uses 'surplus' current for charging purposes.

The parameters screenshot below is not settable, it's per the BMS as limits per type of battery. It doesn't mean this is a max charge rate or anything of the like of Magnum.

As to running on GEN the Cerbo GX new UI has great info and can show you the watts in, watts out, etc. You can look at the detail of supply and demand easily. Also VRM has numerous charts you can use and learn how it works and manages the loads, charging, etc.

Cerbo GX firmware 3.54 as of this posting: