FilterGuy
Solar Engineering Consultant - EG4 and Consumers
That seems unlikely, but you could check by disconnecting the pump
The "Meg" Build
- Thread starter Lt.Dan
- Start date
12VoltInstalls
life passes by too quickly to not live in freedom
But do one thing at a time. Find the problem - then you know what it is/was and it won’t show up again.
Lt.Dan
Solar Wizard
I'm on another trip boondocking in the middle of the desert again right now, and I learned this morning my BMS sh*t the bed and no longer will cutoff at LVD. I went overnight and the battery died (LVD in the app set to 44v). And i woke up at 5am and happened to look at my phone and saw the pack voltage at 38v, with one cell at 1.85v ????
The "Discharge Mosfet" was off, but somehow I was still able to draw power, and it was enough that my propane furnace was still running, and my lights! My guess is the mosfet is toast and stuck open, allowing power past it.
Time to look for another BMS...
The "Discharge Mosfet" was off, but somehow I was still able to draw power, and it was enough that my propane furnace was still running, and my lights! My guess is the mosfet is toast and stuck open, allowing power past it.
Time to look for another BMS...
K8MEJ
Owner, Off-Grid Power Systems
What kind do you have now? The one that died I mean.
Lt.Dan
Solar Wizard
Daly 16s 200a model
K8MEJ
Owner, Off-Grid Power Systems
Thanks. I thought it was Daly but I didn't want to dig through 33 pages to confirm. If I were running just one battery pack, I would buy a second BMS as a backup if I were using one of the inexpensive BMS's. I have four 12v packs so I don't bother carrying a spare in the RV, but I do have one on my bench at home.
For a single 48v pack you might also consider a BMS with a contactor.
Lots of options
Lt.Dan
Solar Wizard
I agree. Ill see if I can get this BMS warranted and maybe keep it as a back up. I'd like a BMS capable of handling 300a, that way it's more than capable of supplying the 2x LV6548s.
Starting research now. I'd also like one with higher amp active balancing... hmmm
Starting research now. I'd also like one with higher amp active balancing... hmmm
K8MEJ
Owner, Off-Grid Power Systems
JK BMS's seem to be highly regarded and have higher current balancing. I've never used them, but I'm sure others can provide lots of info. Andy at Off-Grid Garage (YouTube) did some testing on them a month or two ago.
Lt.Dan
Solar Wizard
I would also like to get a BMS that communicates with the LV6548s, that would be pretty kick ass.
K8MEJ
Owner, Off-Grid Power Systems
MPP LV6548
Just got two of these this week and im waiting on my last set of 280ah cells to arrive. Can’t WAIT to turn them on. Will, do you have any setup videos on this inverter? @DanF @Will Prowse Question if you guys get time: My biggest issue is I can’t figure out what BMS I can use that will...
diysolarforum.com
Did anyone confirm the Seplos BMS works with the LV6548 in Pylontech mode?
Lt.Dan
Solar Wizard
Not yet, they are still waiting on Seplos to update software, whenever that will be. Only downside to the Seplos is they only go up to 200a.MPP LV6548
Just got two of these this week and im waiting on my last set of 280ah cells to arrive. Can’t WAIT to turn them on. Will, do you have any setup videos on this inverter? @DanF @Will Prowse Question if you guys get time: My biggest issue is I can’t figure out what BMS I can use that will...
Did anyone confirm the Seplos BMS works with the LV6548 in Pylontech mode?
I'm looking into the Orion BMS right now, gotta do a lot of research though...
K8MEJ
Owner, Off-Grid Power Systems
With a properly sized contactor it wouldn't matter.
Lt.Dan
Solar Wizard
1) I unhooked both the inverter input and output. As well as disconnected the 50a umbilical cord from the grid to ensure no power to or from anything. I left the solar PV Disconnects on, and turned on the inverters. They both came on, and I currently have 30VAC from earth to trailer. I'm guessing its lower than usual because it is extremely overcast right now and I have almost no solar coming in. When I turn the inverters off, I get less than 40mVAC. When I shutoff the PV Disconnect to the shipping container array, I get less than 40mVAC.
I'm leaning more and more towards the wires that are going to the container. Maybe they are faulty from the manufacture and leaking current into the ground? Or there is just damage somewhere I didnt see. The fluctuating VAC from earth to trailer leans me towards the PV wires more too, I feel it would be more steady if it was actually coming from the AC Output/Input of the grid and/or inverters?
2) I shutoff the DC Circuit breaker than powers the DC-DC Converter and received no difference in VAC from earth to trailer.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Wow, there is not much left to disconnect.... and yet there is still a problem. The only other thing I can think of is to test with only one inverter at a time.
This one really has me scratching my head!!!
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,506
Only PV + and - going to the container, no other wires (including no ground)?
I think I asked you to measure AC voltage of those two PV wires relative to RV chassis, and you said zero.
If they did have AC voltage, that would capacitively couple to container which grounds to earth.
Lt.Dan
Solar Wizard
I did replace the main board in Inverter #1 myself. Could I have messed something up?
4 wires total. 2x Positive PV wires and 2x Negative PV wires. There are 2x 6s2p arrays on the container. No ground wires.
I wonder if I try and drive a grounding rod next to the container and ground the container itself.
It also has me wondering that if I never had the 24x panels on the container, I would have never knew I had a problem? How else can I test this??
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,506
Run a ground wire from RV to the container. That way, if PV panels induce a DC or AC voltage in the container (and the Earth), the RV won't be driven to a voltage relative to Earth. That is proper grounding to protect against cracked/leaking panel anyway.
But first, measure voltage from RV chassis to each of those PV positive and negative wires (again) under conditions where you do measure AC voltage between RV chassis and Earth.
Lt.Dan
Solar Wizard
What size should the ground wire be? I haven't heard or seen of anybody grounding their solar panels before, but then again, I am still the noob here lol.
How should I check voltage without puncturing the insulation?
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
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The proper wire gauge would have sufficient ampacity to carry the current PV strings can produce.
To solve this low-current shock, if it is related to capacitive coupling, any size wire at all would work, even phone wire.
Section "The Array" 2nd paragraph describes frames bonded together and a wire run with the circuit conductors.
www.solarpowerworldonline.com
"Equipment Grounding" page 9
Often, negative PV is referenced to earth ground at the battery. If a wire rubbed through its insulation or a panel cracked (or otherwise developed leakage), PV frame could be hundreds of volts DC, whatever Vmp or Voc is. It could present a lethal shock hazard.
If you have MC connectors, could use a Y cable. If a junction box, access its screw terminals or bring out a pigtail wire (preferably ending in a shrouded conductor so no exposed hot leads.)
To solve this low-current shock, if it is related to capacitive coupling, any size wire at all would work, even phone wire.
Section "The Array" 2nd paragraph describes frames bonded together and a wire run with the circuit conductors.
What is the process of grounding and bonding a solar PV array?
The National Electrical Code (NEC) requires bonding electrically conductive materials and equipment to establish an effective ground-fault current path.
www.solarpowerworldonline.com
"Equipment Grounding" page 9
Often, negative PV is referenced to earth ground at the battery. If a wire rubbed through its insulation or a panel cracked (or otherwise developed leakage), PV frame could be hundreds of volts DC, whatever Vmp or Voc is. It could present a lethal shock hazard.
If you have MC connectors, could use a Y cable. If a junction box, access its screw terminals or bring out a pigtail wire (preferably ending in a shrouded conductor so no exposed hot leads.)
Lt.Dan
Solar Wizard
Ok, I'll order a 500ft spool of 18ga or something to run along with the PV Wires. Do you think the panels on the roof of the trailer should be grounded as well? I'll have to drill a hole in my roof...The proper wire gauge would have sufficient ampacity to carry the current PV strings can produce.
To solve this low-current shock, if it is related to capacitive coupling, any size wire at all would work, even phone wire.
Section "The Array" 2nd paragraph describes frames bonded together and a wire run with the circuit conductors.
What is the process of grounding and bonding a solar PV array?
The National Electrical Code (NEC) requires bonding electrically conductive materials and equipment to establish an effective ground-fault current path.
"Equipment Grounding" page 9
Often, negative PV is referenced to earth ground at the battery. If a wire rubbed through its insulation or a panel cracked (or otherwise developed leakage), PV frame could be hundreds of volts DC, whatever Vmp or Voc is. It could present a lethal shock hazard.
If you have MC connectors, could use a Y cable. If a junction box, access its screw terminals or bring out a pigtail wire (preferably ending in a shrouded conductor so no exposed hot leads.)
How come this is never talked about on Wills YouTube or anywhere else? (unless I am subconsciously ignoring it, lol) Is it different in a mobile application?
