Split Phase LV6548 System - Generator Tie-In

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
G'day,

I currently have a 10Kw Diesel Generator powering a totally off grid cabin. It is wired to my main panel supplying 120/240v.

I have two LV6548 Inverters on their way which I will pair with 16, 480W panels charging 4 SOK 48V 100Ah batteries.

Sun will be limited in the winter months and I imagine I'll have to supplement power with the generator on occasion to both supply power to the cabin and charge the batteries (once above 0 degrees C). It gets cold here in the great white north of Canada.

My question is:

Should I connect the generator directly to the inverters or should I run the 120/240 from the generator to a seperate breaker in the main panel. I could have one breaker in the panel for the inverters and one for the generator. I'd just have to ensure that both were not on at the same time and buy a seperate 48V Battery Charger. There is probably a transfer switch that would make this fool proof.

Thank you to all those who chime in!
 

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
I've decided to go with a mechanical interlock in my main panel and add a 60A Breaker for the Generator. That way, the Inverters and the Generator can not be on at the same time.
 

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
Next question... Can I use a feed from the panel, when powered by the generator, to feed one, or both of the inverters which will in turn, charge the batteries?

Or, should I just buy a good 48V charger?
 

timselectric

If I can do it, you can do it.
Joined
Feb 5, 2022
Messages
6,867
I would run the generator into the inverters input and run the inverters output to the panel. These inverters are designed for this situation. If your generator is capable of remote start, they can start it when the battery is low.
 

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
Thank you for taking the time to respond.

Would you run one phase of the generator to one inverter and the other phase to the other?

I think the AC inputs are 120V single phase on the LV6548's?

Cheers
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
2,637
Thank you for taking the time to respond.

Would you run one phase of the generator to one inverter and the other phase to the other?

I think the AC inputs are 120V single phase on the LV6548's?

Cheers
If the inverters are configured for split phase, yes. I put a generator socket on my wall, to a box with a 2 pole breaker, then split L1 to one inverter and L2 to the other inverter. The breaker is for protection and also an easy way to turn the generator input off or on, if need be.
 

Samsonite801

Photon Sorcerer
Joined
Oct 15, 2020
Messages
2,343
I would run the generator into the inverters input and run the inverters output to the panel. These inverters are designed for this situation. If your generator is capable of remote start, they can start it when the battery is low.

As far as I always knew, the LV6548's will only allow battery charging if the inverters are turned off (in standby)...

For this reason, I bought 2 separate 120v to 48v battery chargers (one per generator leg) to allow charging the battery bank while the inverters are running.
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
2,637
As far as I always knew, the LV6548's will only allow battery charging if the inverters are turned off (in standby)...

For this reason, I bought 2 separate 120v to 48v battery chargers (one per generator leg) to allow charging the battery bank while the inverters are running.
Can you post the manual or a link to the manual? I would be surprised if charging is limited to Standby.

edit, addition....I have two Growatts and I think they operate with the same mode options as the MPPs do. I recently did a test of generator charging. I can't find the thread (someone else's thread) but I posted my report there. If the inverter was on and the battery was at a state where the inverter thought charging was a good idea, it would charge in Standby or when it was on (making power). The battery voltage had to get down to where the inverter was logging something less than 100% battery SOC before it would start charging. It would go from 100% right to 75% and then start charging from the AC input of the inverter.
 
Last edited:

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
2,637
Below is my understanding....same as my Growatt.

1656001502020.png
 

Attachments

  • 1656001450764.png
    1656001450764.png
    64.3 KB · Views: 4

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
Excellent information.

I guess I'll try it when they arrive and experiment.

I will report back here with my findings.
 

Samsonite801

Photon Sorcerer
Joined
Oct 15, 2020
Messages
2,343
Excellent information.

I guess I'll try it when they arrive and experiment.

I will report back here with my findings.

Also refer to this thread:



And this thread:




Ultimately it appeared that MPP Solar confirmed the following is true (Post 29 of the last thread link):



I guess the LV6548 don't have to be in manual bypass mode (for charging), but rather will be in an auto-AC-pass-through mode, meaning the generator must be sized large enough to both power the household AC loads, and power the battery charging at same time.

Probably it uses the same mosfets the inverter circuit would normally use, to operate the battery charging circuit, so cannot invert at same time while charging. Inverter does not need to run at this time, as the generator will be supplying the all the load, but will require you have enough watts from the generator to handle the entire load sum...
 
Last edited:

timselectric

If I can do it, you can do it.
Joined
Feb 5, 2022
Messages
6,867
Thank you for taking the time to respond.

Would you run one phase of the generator to one inverter and the other phase to the other?

I think the AC inputs are 120V single phase on the LV6548's?

Cheers
Yes
 

timselectric

If I can do it, you can do it.
Joined
Feb 5, 2022
Messages
6,867
And batteries can charge when inverting, in standby, when sleeping, and even if turned off.
 

ccpeabody

New Member
Joined
Jun 12, 2022
Messages
28
Just to follow up on my original post. I've set up my system and wired one phase and a neutral from the generator to the AC Input of inverter one and the second phase and a neutral from the generator to the AC Input of the second inverter.

When the generator starts up, the batteries begin to charge. Works exactly as DThames suggested it would in his post above.

An interesting side note: I don't actually know the size of the generator I'm running. It's a 3 cyl Perkins Diesel unit running a generator off the output shaft but there are absolutely no markings on the generator housing itself. I would guess it's light weight as I can load it down quite easily with a chop saw and an air compressor. Nonetheless, it charges the batteries via the two LV6548's as long as the load at the cabin is low. Increase the demand in the cabin and the batteries stop charging until the load decreases.

Now here is the interesting part. I also have a Champion 9000W generator that we have had for years. It will run the chop saw and the air compressor all day long and never fail but it won't charge the batteries through the LV6548's.

Some have suggested that the LV6548's require an inverter type generator with a pure sine wave to allow for charging but the generator on the big Perkins is certainly not an inverter generator.
 

timselectric

If I can do it, you can do it.
Joined
Feb 5, 2022
Messages
6,867
I guess that there's something about the power from the champion that the inverter doesn't like. I would have thought that it would be cleaner.
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
2,637
Just to follow up on my original post. I've set up my system and wired one phase and a neutral from the generator to the AC Input of inverter one and the second phase and a neutral from the generator to the AC Input of the second inverter.

When the generator starts up, the batteries begin to charge. Works exactly as DThames suggested it would in his post above.

An interesting side note: I don't actually know the size of the generator I'm running. It's a 3 cyl Perkins Diesel unit running a generator off the output shaft but there are absolutely no markings on the generator housing itself. I would guess it's light weight as I can load it down quite easily with a chop saw and an air compressor. Nonetheless, it charges the batteries via the two LV6548's as long as the load at the cabin is low. Increase the demand in the cabin and the batteries stop charging until the load decreases.

Now here is the interesting part. I also have a Champion 9000W generator that we have had for years. It will run the chop saw and the air compressor all day long and never fail but it won't charge the batteries through the LV6548's.

Some have suggested that the LV6548's require an inverter type generator with a pure sine wave to allow for charging but the generator on the big Perkins is certainly not an inverter generator.
A normal generator produces a sine wave as a result of the spinning magnetic field. It is just a natural output of the design.

My Growatt has a voltage input range 2 or 3 setting types, one allows a fairly large input range. Look for a similar setting and look at the voltage out of the Champion. Maybe the output volts are high (out of range). You might try some things like adding an electrical load to the Champion and see if putting it under load will change the output (somehow) and allow the AIO to like it.

Regarding your charging on the Perkins powered generator, what is your max AC charging amps set on your inverter? Is your load taking all of those amps and leaving none for the battery charging? On most of the AIO that require a battery, all of the power comes in through the battery charger, so if you have it throttled down, there is a hard limit to the gen power and if the load takes it all, no charging.....If my understanding is not flawed.
 

Samsonite801

Photon Sorcerer
Joined
Oct 15, 2020
Messages
2,343
I guess that there's something about the power from the champion that the inverter doesn't like. I would have thought that it would be cleaner.

Also check the Hz output of your Champion (with a Kill-A-Watt) and make sure it's holding steady 60Hz, otherwise the inverter may reject the power input. You fine tune the Hz by adjusting the RPM, via the governor linkage adjustments which regulate the RPM at 3600 RPM for 2-pole generators (or its 1800 RPM on a 4-pole generator)...

Inverter generators don't have this dependency to having correct / steady RPM and don't apply to the above rule, as the RPM is decoupled from the inverter output.
 

timselectric

If I can do it, you can do it.
Joined
Feb 5, 2022
Messages
6,867
Also check the Hz output of your Champion (with a Kill-A-Watt) and make sure it's holding steady 60Hz, otherwise the inverter may reject the power input. You fine tune the Hz by adjusting the RPM, via the governor linkage adjustments which regulate the RPM at 3600 RPM for 2-pole generators (or its 1800 RPM on a 4-pole generator)...

Inverter generators don't have this dependency to having correct / steady RPM and don't apply to the above rule, as the RPM is decoupled from the inverter output.
Replied to the wrong person.
It's not my generator with an issue.
 
Top