MEP803A low output for solar system backup

Coug said:

If it's not loading down the generator, then I'd say it's likely that the bottleneck here is your charge controller only asking for 5500 watts of power, rather than the generator not producing the power. Just because the solar panels are capable of producing more than 7200 watts doesn't always mean that it's all being used.

Is the generator getting bogged down and straining to produce this power, or is it just chugging along like normal?

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DieselAddict said:

How is the generator connected to the system? Is the generator failing to put out its full rating or is the system not demanding enough from the generator?

I have a XW6848 running my system and on that unit generator load is programmable in the inverter. There are also settings such as minimum voltage that can affect how much power is drawn from the generator.

I don't think we know enough about your situation to provide better input.

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jrhunter said:

It seems to be chugging along without effort. According to my system, the system seems to be using all the output for loads and battery charging.

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DieselAddict said:

How is the generator connected to the system? Is the generator failing to put out its full rating or is the system not demanding enough from the generator?

I have a XW6848 running my system and on that unit generator load is programmable in the inverter. There are also settings such as minimum voltage that can affect how much power is drawn from the generator.

I don't think we know enough about your situation to provide better input.

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jrhunter said:

The generator has an auto start and the power leads are connected directly to the power distribution panel. When the system is close to a full charge the generator and solar output is reduced to what ever level is required to charge the batteries. When the generator starts it takes about 3 minutes to start supplying power to the power distribution panel. The generator does not really speed up when the output begins, but I can tell the generator is under a little load. I don't know if it is operating at 1800 rpms, but it never seems to idle down when the generator is shutting down. Could I have a problem with the governor? Thank you.

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Coug said:

These generators don't change speed when running. Or at least not more than a very slight amount. It's not enough to really notice compared to the increasing amount of noise from the extra work the gen is doing with a heavy load. The volume gets louder, the tone deepens a little, but the frequency of the noise doesn't do much.

The 3 minute wait at startup is probably a function built into your charge controller to allow the generator to warm up a little before being put under a load. There will also be a cool down period at the end where the controller lets the generator run for a few minutes to make sure it's cooled off enough to safely shut down.

If the generator is chugging along not dropping in power (have you looked at the HZ meter? multiple that x30 to get engine RPMs) then the generator is doing it's job properly.

Basic lesson in generators.
The generator head will put out the amount of power the load is trying to draw. If the load is trying to draw too much power, then one of two things will happen. Either the engine bogs down because it doesn't produce enough power to keep the electromagnetic fields in the generator spinning against the resisting field created by the load drawing power, or somewhere in the system a wire is going to get hot from too much amperage going through it and you'll melt that wire, creating an open circuit through which no power will flow, or two wires will melt together through the insulation around the wires resulting in a short circuit.

If your unit is producing the required voltage, and is running at the proper speed to produce 60hz power, then what you are talking about is not a problem with the generator. The generator is likely functioning how it's supposed to.



Reading through the manual for the Conext SW charger/inverter it looks like AC input is limited to a 30 amp breaker, or 7200 watts. You never specified what model of equipment you're running, so I'll go with this one for now.

(When you say 5500 watts input, does that mean 5500 watts total, or is that 5500 watts going to the batteries to charge them? If it's 5500 total and not just to the batteries, you can disregard the next part, as it's mostly speculation about what could be occurring)

So maximum your system (if it's this model) would be able to draw is 7000 watts or so before tripping the breaker. That 7kw is going to go both to charging the batteries and bypass the inverter to output to your house/load as well. If your house/loads are drawing 1500 watts of power, then the battery input at that point will be 5500 watts or less. It doesn't convert all the generator power into DC power to charge the batteries just to convert it back to AC again.

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Coug said:

These generators don't change speed when running. Or at least not more than a very slight amount. It's not enough to really notice compared to the increasing amount of noise from the extra work the gen is doing with a heavy load. The volume gets louder, the tone deepens a little, but the frequency of the noise doesn't do much.

The 3 minute wait at startup is probably a function built into your charge controller to allow the generator to warm up a little before being put under a load. There will also be a cool down period at the end where the controller lets the generator run for a few minutes to make sure it's cooled off enough to safely shut down.

If the generator is chugging along not dropping in power (have you looked at the HZ meter? multiple that x30 to get engine RPMs) then the generator is doing it's job properly.

Basic lesson in generators.
The generator head will put out the amount of power the load is trying to draw. If the load is trying to draw too much power, then one of two things will happen. Either the engine bogs down because it doesn't produce enough power to keep the electromagnetic fields in the generator spinning against the resisting field created by the load drawing power, or somewhere in the system a wire is going to get hot from too much amperage going through it and you'll melt that wire, creating an open circuit through which no power will flow, or two wires will melt together through the insulation around the wires resulting in a short circuit.

If your unit is producing the required voltage, and is running at the proper speed to produce 60hz power, then what you are talking about is not a problem with the generator. The generator is likely functioning how it's supposed to.



Reading through the manual for the Conext SW charger/inverter it looks like AC input is limited to a 30 amp breaker, or 7200 watts. You never specified what model of equipment you're running, so I'll go with this one for now.

(When you say 5500 watts input, does that mean 5500 watts total, or is that 5500 watts going to the batteries to charge them? If it's 5500 total and not just to the batteries, you can disregard the next part, as it's mostly speculation about what could be occurring)

So maximum your system (if it's this model) would be able to draw is 7000 watts or so before tripping the breaker. That 7kw is going to go both to charging the batteries and bypass the inverter to output to your house/load as well. If your house/loads are drawing 1500 watts of power, then the battery input at that point will be 5500 watts or less. It doesn't convert all the generator power into DC power to charge the batteries just to convert it back to AC again.

Click to expand...

Coug said:

These generators don't change speed when running. Or at least not more than a very slight amount. It's not enough to really notice compared to the increasing amount of noise from the extra work the gen is doing with a heavy load. The volume gets louder, the tone deepens a little, but the frequency of the noise doesn't do much.

The 3 minute wait at startup is probably a function built into your charge controller to allow the generator to warm up a little before being put under a load. There will also be a cool down period at the end where the controller lets the generator run for a few minutes to make sure it's cooled off enough to safely shut down.

If the generator is chugging along not dropping in power (have you looked at the HZ meter? multiple that x30 to get engine RPMs) then the generator is doing it's job properly.

Basic lesson in generators.
The generator head will put out the amount of power the load is trying to draw. If the load is trying to draw too much power, then one of two things will happen. Either the engine bogs down because it doesn't produce enough power to keep the electromagnetic fields in the generator spinning against the resisting field created by the load drawing power, or somewhere in the system a wire is going to get hot from too much amperage going through it and you'll melt that wire, creating an open circuit through which no power will flow, or two wires will melt together through the insulation around the wires resulting in a short circuit.

If your unit is producing the required voltage, and is running at the proper speed to produce 60hz power, then what you are talking about is not a problem with the generator. The generator is likely functioning how it's supposed to.



Reading through the manual for the Conext SW charger/inverter it looks like AC input is limited to a 30 amp breaker, or 7200 watts. You never specified what model of equipment you're running, so I'll go with this one for now.

(When you say 5500 watts input, does that mean 5500 watts total, or is that 5500 watts going to the batteries to charge them? If it's 5500 total and not just to the batteries, you can disregard the next part, as it's mostly speculation about what could be occurring)

So maximum your system (if it's this model) would be able to draw is 7000 watts or so before tripping the breaker. That 7kw is going to go both to charging the batteries and bypass the inverter to output to your house/load as well. If your house/loads are drawing 1500 watts of power, then the battery input at that point will be 5500 watts or less. It doesn't convert all the generator power into DC power to charge the batteries just to convert it back to AC again.

Click to expand...

jrhunter said:

This is really good information. I have attached 3 screen shots of my Connext Combox demonstrating the issue. The first photo shows 1880 watts of solar input, and 5168 watts of generator input. The batteries are showing a 69% state of charge and loads are 1051.
The next picture shows 2706 watts of solar, and 5193 watts of generator input. There is 1056 watts of load.
The last photo is with the solar system disconnected. The generator is purducing 5282 watts with the total load of 990 watts.
As you can see by the generator numbers, there is little difference between all 3 readings. I hope I explained this correctly. I am stumped why the generator output does not increase. Thank you.

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