LV6548 AC input settings

[EastTexCowboy]

I designed the same system I have for my father. I had to start his at 53v return to solar. 54v for him was around what yours is, Then after 4 months moved it up to 54V. I’m sure there’s a technical reason. To me it just seemed like break in and balancing of the rack batteries. Either way, it’s fun to tinker with every now and then anyway.

So I finally had a night when my batteries dropped down low enough they should have switched to grid. I had changed the trigger voltage from 51v to 50v since the 51v triggered at 26%. This time it got down to 16% and didn't trigger so I guess I'll go back to 51v and see what happens. In short, you were right and it appears to be a moving target. Oh well, I'm planning to install the other 16 panels next week that have been in the shop for months, then add another 30kWh in batteries so maybe it will never switch to grid. I can live with that.

 

[Gavin Stone]

So I finally had a night when my batteries dropped down low enough they should have switched to grid. I had changed the trigger voltage from 51v to 50v since the 51v triggered at 26%. This time it got down to 16% and didn't trigger so I guess I'll go back to 51v and see what happens. In short, you were right and it appears to be a moving target. Oh well, I'm planning to install the other 16 panels next week that have been in the shop for months, then add another 30kWh in batteries so maybe it will never switch to grid. I can live with that.

51v does seem to be a good number. And it really depends on the size of your battery bank. A smaller bank will have a higher voltage sag with an inductive load. So it will trip too early sometimes. You definitely won’t have that problem. You adding another rack of batteries?

 

[EastTexCowboy]

51v does seem to be a good number. And it really depends on the size of your battery bank. A smaller bank will have a higher voltage sag with an inductive load. So it will trip too early sometimes. You definitely won’t have that problem. You adding another rack of batteries?

Yeah, I'm gonna bite the bullet. We're doing the second array of panels next week which will take me to 14kw but not really since these LV6548 inverters clip my input at around 17a. I end up getting a little under 6kw from the current 16 panels so that should go to 12kw with double the panels. I want to put at least one or two of my new Mitsubishi heat pumps on solar and that's going to work way better if I double the battery storage as well. I've gone back and forth on DIY batteries vs another rack of EG4. I'm probably going with the EG4 again. I'm only 3 hours away so I can drive up to Sulpher Springs and pick them up and check out the Signature Solar facility. I'll try to take some pictures if they don't mind. Maybe I can catch @SignatureSolarJames doing one of his experiments or videos!

Maybe next phase I'll do some DIY batteries. But this hemorrhaging of money needs to slow down for a few months. If this size battery bank works out well I might look at upgrading to different inverters and put these MPPs on the shop or something. But when I look at all the alternatives there's always something I don't like, which is how I ended up with these. I'd like to do something like the EG4 8KW but it looks like it only supports 3kw of PV per input x 4 inputs. I'd have to reconfigure all the panels which would be a pain. I figure this tech is changing so fast there will be something wondermous out there in another year or two.

 

[Zwy]

So I finally had a night when my batteries dropped down low enough they should have switched to grid. I had changed the trigger voltage from 51v to 50v since the 51v triggered at 26%. This time it got down to 16% and didn't trigger so I guess I'll go back to 51v and see what happens. In short, you were right and it appears to be a moving target. Oh well, I'm planning to install the other 16 panels next week that have been in the shop for months, then add another 30kWh in batteries so maybe it will never switch to grid. I can live with that.

How large is the bank now?

Last Monday, I had my Batrium trip the ABB breaker on a critical fault, the cell voltage had dropped low enough for a trip. I had been still setting everything up and had the BMS low voltage cutoff set higher than the EG4 cutoff.

I've been using more electricity in the house than ever before. I've been using some electric heaters for dump loads until I get the mini splits installed this summer. Over 50 Kwh per day usage. Certainly cuts my gas usage down.

 

[EastTexCowboy]

How large is the bank now?

Last Monday, I had my Batrium trip the ABB breaker on a critical fault, the cell voltage had dropped low enough for a trip. I had been still setting everything up and had the BMS low voltage cutoff set higher than the EG4 cutoff.

I've been using more electricity in the house than ever before. I've been using some electric heaters for dump loads until I get the mini splits installed this summer. Over 50 Kwh per day usage. Certainly cuts my gas usage down.

30kWh right now. Six of the EG4 Lifepower4 in a rack. I think you're gonna like those mini splits. We went with the version that's essentially mini-split condenser units with all the same tech and matching air handlers on the inside so we're still using the ducted system. The silence is amazing. I can barely hear the condenser units when I'm standing right by them. They're outside our bedroom so it has always been a little annoying. Now it's just quiet. Even the air handlers are quiet.

I'm so looking forward to getting the last of the panels installed and another rack of batteries. I think once that happens I'll be doing some of what you're doing - using it because it's there.

 

[Zwy]

I've been running a SCC on each inverter at the max 4.0Kw. My array is JA Solar 16 530W panels, so I'm possibly missing 240W per string, however with efficiency losses it's may be all I can get. Under full SCC load, the PV runs around 365V@11A. 420 foot one way run from panels to SCC.

With cloud edge effect, you sometimes see a surge to higher than 4.0Kw but the SCC must clip it pretty quick.

The larger battery bank is the way to go IMO. I can have less PV and maximize it's charging as the bank will take all it can produce.

 

[EastTexCowboy]

I've been running a SCC on each inverter at the max 4.0Kw. My array is JA Solar 16 530W panels, so I'm possibly missing 240W per string, however with efficiency losses it's may that is all I can get. Under full SCC load, the PV runs around 365V@11A. 420 foot one way run from panels to SCC.

With cloud edge effect, you sometimes see a surge to higher than 4.0Kw but the SCC must clip it pretty quick.

The larger battery bank is the way to go IMO. I can have less PV and maximize it's charging as the bank will take all it can produce.

That's probably my biggest complaint about the LV6548 - the 250v 18a max input from PV. It really restricts your options.

I agree on the larger battery bank. I figure every hour my panels are making power I can't save or use is that much production I've lost and can never get back. Maximizing how much you can use out of what you can produce is a big deal to me.

 

[Zwy]

30kWh right now. Six of the EG4 Lifepower4 in a rack.

I was using about 10% overnight on 53Kwh. I switched off the AC input yesterday and it was about 15% overnight as the inverter overhead seems to come off AC input when connected to grid power. But it was a low about 10F last night so the furnace ran more.

I think you're gonna like those mini splits. We went with the version that's essentially mini-split condenser units with all the same tech and matching air handlers on the inside so we're still using the ducted system. The silence is amazing. I can barely hear the condenser units when I'm standing right by them. They're outside our bedroom so it has always been a little annoying. Now it's just quiet. Even the air handlers are quiet.

My furnace likes watts, I'm thinking of just using the inside evaporator units, but the cleaning aspect may change my mind.

I'm so looking forward to getting the last of the panels installed and another rack of batteries. I think once that happens I'll be doing some of what you're doing - using it because it's there.

My plan all along is to move heating in fall and spring to electric using mini splits and cut down LP gas usage. Mid winter will still be LP gas, it gets cold here, -20F not unusual for several weeks.

 

[Gavin Stone]

Yeah, I'm gonna bite the bullet. We're doing the second array of panels next week which will take me to 14kw but not really since these LV6548 inverters clip my input at around 17a. I end up getting a little under 6kw from the current 16 panels so that should go to 12kw with double the panels. I want to put at least one or two of my new Mitsubishi heat pumps on solar and that's going to work way better if I double the battery storage as well. I've gone back and forth on DIY batteries vs another rack of EG4. I'm probably going with the EG4 again. I'm only 3 hours away so I can drive up to Sulpher Springs and pick them up and check out the Signature Solar facility. I'll try to take some pictures if they don't mind. Maybe I can catch @SignatureSolarJames doing one of his experiments or videos!

Maybe next phase I'll do some DIY batteries. But this hemorrhaging of money needs to slow down for a few months. If this size battery bank works out well I might look at upgrading to different inverters and put these MPPs on the shop or something. But when I look at all the alternatives there's always something I don't like, which is how I ended up with these. I'd like to do something like the EG4 8KW but it looks like it only supports 3kw of PV per input x 4 inputs. I'd have to reconfigure all the panels which would be a pain. I figure this tech is changing so fast there will be something wondermous out there in another year or two.

I think you’ll be happy with 60kw. When I upgraded to over 14kw of panels and 58kw of batteries it was a game changer. I’ve been running completely off grid since the beginning of the year. I thought the same thing about the 8kw inverters. I’d still like to get my hands on one to review it. Maybe someday. At this point I’m thinking I may try Schneider. They are just fantastic looking units.

 

[Zwy]

That's probably my biggest complaint about the LV6548 - the 250v 18a max input from PV. It really restricts your options.

Yes, but you don't get the disco fever like you will with the EG4.

I ran some wire yesterday to move some circuits off the upstairs fuse panel that will get replaced this week. One thing I noticed is the flicker still occurred with that panel off. Another thing I found was I was running a new wire to power my bedroom lights and fan and was twisting the neutrals together with the lineman's pliers. There was a slight arc to ground if I touched the pliers to the metal part of the switch. Granted, it's a parallel path but the circuit was off. Voltmeter shows about 0.5V and about 0.5A. I have one inverter bonded with bonding screw as I'm using a 3 pole transfer switch. My N-G bond is 100 feet away at the meter socket on the utility pole but that should not have any effect with the inverter bonded and a 3 pole with neutral switched. I do have a ground rod right at loads panel and the unbonded main in the house.

I didn't think there would be that much impedence. Makes me wonder if this isn't the reason for the flicker due to the inverter output moving between 111V to 128V.

I agree on the larger battery bank. I figure every hour my panels are making power I can't save or use is that much production I've lost and can never get back. Maximizing how much you can use out of what you can produce is a big deal to me.

You get a faster ROI, no doubt about it.

 

[EastTexCowboy]

Yes, but you don't get the disco fever like you will with the EG4.

I ran some wire yesterday to move some circuits off the upstairs fuse panel that will get replaced this week. One thing I noticed is the flicker still occurred with that panel off. Another thing I found was I was running a new wire to power my bedroom lights and fan and was twisting the neutrals together with the lineman's pliers. There was a slight arc to ground if I touched the pliers to the metal part of the switch. Granted, it's a parallel path but the circuit was off. Voltmeter shows about 0.5V and about 0.5A. I have one inverter bonded with bonding screw as I'm using a 3 pole transfer switch. My N-G bond is 100 feet away at the meter socket on the utility pole but that should not have any effect with the inverter bonded and a 3 pole with neutral switched. I do have a ground rod right at loads panel and the unbonded main in the house.

I didn't think there would be that much impedence. Makes me wonder if this isn't the reason for the flicker due to the inverter output moving between 111V to 128V.


You get a faster ROI, no doubt about it.

I have never had a flicker until I put the washing machine on solar. When it's running you can watch the kitchen lights flicker exactly in time with the sound of the washing machine motor. It's gotta be something with the inverter because it doesn't do that when it's on the grid. That said, it's not bad and it's not frequent so I'm not going to lay awake at night about it just yet.

Yeah, I would question why you're getting current under those circumstances. We're set up pretty much exactly the same and I haven't had that issue that I know of. One screw removed, three pole transfer switch, etc. Makes me want to come up with a way to test it conclusively. I'm open to suggestions.

 

[Zwy]

Like I said, I measured using the DVOM with the circuit off between neutral and ground. The circuit runs directly back to CL panel. Why this voltage/amps would be there is quite puzzling. I would think impedance would prevent current from coming up that neutral in a parallel path to return to the inverter.

The flicker is very intermittent. I have yet to find a load causing it. I do see the output voltage on the inverters fluctuate when it happens. This is a clue. I swapped the L1 and L2 on the 2 pole breaker directly after the inverters and it followed the L2 circuit. Instead of 2P2 fluctuating output voltage, I now see it on L1. Have switched off every circuit on the leg when the flicker occurs, can't pin it down.

My washing machine is fairly new Speed Queen with a transmission, I never see the light flicker when it runs. I actually think the dryer, even though it isn't running, might be the cause of the flicker. I'll know more later today, need to observe the flicker, then turn off the breaker to the dryer.

 

[Zwy]

Getting close to max sun, over 130A into battery. Just wow.

 

[EastTexCowboy]

Like I said, I measured using the DVOM with the circuit off between neutral and ground. The circuit runs directly back to CL panel. Why this voltage/amps would be there is quite puzzling. I would think impedance would prevent current from coming up that neutral in a parallel path to return to the inverter.

The flicker is very intermittent. I have yet to find a load causing it. I do see the output voltage on the inverters fluctuate when it happens. This is a clue. I swapped the L1 and L2 on the 2 pole breaker directly after the inverters and it followed the L2 circuit. Instead of 2P2 fluctuating output voltage, I now see it on L1. Have switched off every circuit on the leg when the flicker occurs, can't pin it down.

My washing machine is fairly new Speed Queen with a transmission, I never see the light flicker when it runs. I actually think the dryer, even though it isn't running, might be the cause of the flicker. I'll know more later today, need to observe the flicker, then turn off the breaker to the dryer.

I'll be very interested in what you find. You're obviously on the trail of it with the switching of the legs.

Our washer and dryer are fairly new (3 or 4 years old) and top of the line giant beasts. I come back to that it doesn't happen if the washer is on the grid.

 

[EastTexCowboy]

Getting close to max sun, over 130A into battery. Just wow.

Pretty amazing, yep.

 

[Zwy]

I have an electric heater running plus she is running the dryer after a load of wash earlier (1.753Kw) . I'm still putting in around 5500W (over 100A) into the batteries. Another 45 minutes and I'll be at full charge. Need to increase dump loads.

 

[EastTexCowboy]

I have an electric heater running plus she is running the dryer after a load of wash earlier (1.753Kw) . I'm still putting in around 5500W (over 100A) into the batteries. Another 45 minutes and I'll be at full charge. Need to increase dump loads.

Making me jealous. I'm looking forward to getting the new panels and batteries added. But I'm not jealous about the weather. Didn't you say down to -20 for extended periods? Ugh. I try to avoid leaving the house if it gets below 40!

Of course it goes the other direction in the summer. I don't have the spikes in usage in summer like when we get a day in the teens occasionally in winter but we get pretty high AC usage for months. I'm looking foward to running the new AC units on solar and make a big dent in that.

Then there's the whole thing of working out in the 100 plus degree heat with 90% humidity. I can't handle it like I could 20 or 30 years ago. Huh. I guess that makes me a wuss. Can't handle the heat and can't handle the cold. Dang it.

 

[Skypower]

I would probably change the battery DC breaker asap. Some of those copycat breakers can overheat and not disconnect or just be a point of resistance. I do not know if that’s what you have other than my bad memory. I run the original “Buss” brand marketed by Blue Sea and they are also rated at 48v max. Yes they are probably the wrong component for the job but they’ve been in use for over a year, seen dryer plus HVAC loads at the same time and don’t get any warmer than the cables. It’s been opened and closed at voltage (resistors used) but never under high load. Truth be told there really isn’t 48volt system that doesn’t exceed that because even a lead acid system is “empty” at that point. At the time of building the system couldn’t find a reasonably affordable DC breaker, now there’s several. If I were to “do over” - nope. Next time you have your system down, install some cable color matching adhesive lined heat shrink on your lugs. The welding cable non tined wire can oxidize with time and moisture. If I had to do it over again, I’d be using a wire way too.

 

[EastTexCowboy]

I would probably change the battery DC breaker asap. Some of those copycat breakers can overheat and not disconnect or just be a point of resistance. I do not know if that’s what you have other than my bad memory. I run the original “Buss” brand marketed by Blue Sea and they are also rated at 48v max. Yes they are probably the wrong component for the job but they’ve been in use for over a year, seen dryer plus HVAC loads at the same time and don’t get any warmer than the cables. It’s been opened and closed at voltage (resistors used) but never under high load. Truth be told there really isn’t 48volt system that doesn’t exceed that because even a lead acid system is “empty” at that point. At the time of building the system couldn’t find a reasonably affordable DC breaker, now there’s several. If I were to “do over” - nope. Next time you have your system down, install some cable color matching adhesive lined heat shrink on your lugs. The welding cable non tined wire can oxidize with time and moisture. If I had to do it over again, I’d be using a wire way too.

I changed out my DC breaker a while back based on this thread. I now have one of the 200A x 2 from Watts247 that @Gavin Stone recommended. It's the one Ian recommends for these inverters as well.

 

[Skypower]

Yeah I missed that. Good decision!