Hi All
I just installed A MN3024DIY in my Travel Trailer.
Set Up
Battery: DIY Lifepo4 8 cell 24v 100ah 80A BMS
Controller: MN3024DIY
Solar Panels: 250w and 130w
So far so good
Runs every thing in the camper.
just not at the same time.
Right now I do not have enough battery to use the full 3000W only able to use about 2000W.
There are 2 things I do not like about the MN3024DIY.
1: The AC output connection are hard to access and connect NO room.
2: The minimum PV input voltage of 30V is to high my 250W panel likes to operate at 28V so I had to add A second panel.
My Tracer 4215BN input range is 2v-108v.
The plan is to add another Battery and put about 400W-600W of panels on the roof next year.
Thank
Jim
So you have two PV panels in series ?
Are the PV you have matched in voltage ?
You are probably limiting your higher power pv to the current of the lower one - I think that is how that works .
Larry
Yes I have the 250W and the 130W in series.
Yes the 130W may drag down the 250W but at this point and time it will have to do.
My budget will not let me buy matching panels.
okay - yeah you do what you gotta do !
Lots of used PV out there these days so maybe you can find some in your budget.
Big PV projects replace with newer panels, and they may have scratch and dent stuff too.
Prices on those should be really reasonable since the cost of new PV is so low for them.
Larry
Ran into a little snag.
The manual does not tell how to reset or clear alarms without shutting the whole thing down.
Does anyone know how to clear an alarm without shutting the system down?
Thanks
Jim
Quote from: Oldtimmer on May 10, 2022, 08:50:18 AM
Hi All
I just installed A MN3024DIY in my Travel Trailer.
Set Up
Battery: DIY Lifepo4 8 cell 24v 100ah 80A BMS
Controller: MN3024DIY
Solar Panels: 250w and 130w
So far so good
Runs every thing in the camper.
just not at the same time.
Right now I do not have enough battery to use the full 3000W only able to use about 2000W.
There are 2 things I do not like about the MN3024DIY.
1: The AC output connection are hard to access and connect NO room.
2: The minimum PV input voltage of 30V is to high my 250W panel likes to operate at 28V so I had to add A second panel.
My Tracer 4215BN input range is 2v-108v.
The plan is to add another Battery and put about 400W-600W of panels on the roof next year.
Thank
Jim
Hi Jim,
In looking at the manual for the 4215BN CC, the MPP Input voltage range, is:
"MPP voltage range Battery voltage+2V～108V".
And, at only 2 volts above battery voltage, the CC has essentially NO Headroom to operate. You really need a number of volts, above two, for the MPPT function to do anything meaningful, IMO.
I know nothing about clearing Alarms. Good Luck, Vic
... And, Jim, will add another thought;
When PVs are run in series strings, generally, the Imp specs of each panel is what matters most, regarding string power.
Using guesses about the actual ratings of the dissimilar PVs in your strings, assume that the 130 watt PVs might produce about, 7.4 amps at STC. And, assuming that the 250 watt PVs are 60 Cell panels, which would mean that the Vmp, is about 31-ish volts. This would mean that the STC Imp is about 8 amps. These two, assumed values are very close to each other, if nominally correct.
They are probably within ten-ish percent of each other. Personally would not worry, at all about this probable slight difference.
FWIW, IMO, etc, Vic
The 250w panel specs
Pmax 250W
Vmp 30.1
Imp 8.3
Voc 37.2
Isc 8.87
The 135W Panel specs
Pmax 135W
Vmp 17.7
Imp 7.63
Voc 22.1
Isc 8.37
I am looking at 4 100W panels to mount to the roof of the camper.
As soon as my budget will allow the 24v Lifepo4 battery and the MN3024DIY destroyed my budget.
By the way so far so good the unit runs everything I need it to run.
A few hiccups all operator head space lol my fault.
Thanks for the reply
Found a fault with this unit.
Bad EMI or EMF radio interference.
My Ameture Radios or Ham Radio has a lot of noise when this unit is running.
So if your a ham and you plan on running an HF rig when your camping you will need to shut this unit down.
:-\
Quote from: Oldtimmer on May 17, 2022, 06:53:50 PM
Found a fault with this unit.
Bad EMI or EMF radio interference.
My Ameture Radios or Ham Radio has a lot of noise when this unit is running.
So if your a ham and you plan on running an HF rig when your camping you will need to shut this unit down.
:-\
Hi Jim,
Is your RV connected to shorepower, when you noticed the RFI?
What are frequency ranges, where you notice this RFI?
If you can, try switching OFF, the breaker for the PV input to the DIY inverter/charger. Does the RFI diminish? Generally, the most affected frequencies are in the HF range, and, lower HF frequencies have stronger RFI, than do the upper frequency ranges. AND, often the Charge Controller contributes more to RFI, than do inverters (yes, a broad generality).
There have been a number of discussions on RFI issues, with power electronics, on this Forum. Here is one:
http://midniteftp.com/forum/index.php?topic=4950.0
For additional ones, try searching for, " RFI ", from the Index (home) page.
Using Ferrite cores (Mix 31 for HF are best), shielding power conductors, moving antennas from near the PVs, and power electronics can all help, often, these help a lot.
This is a broad topic, later, Vic
I have never tested the DIY's for EMI.
What bands or frequencies ?
boB
No RFI problems when connected to shore power.
10m-160m about every 60khz - 10, 15, and 17 are tolerable the lower you go in frequency the worse it gets.
Have not tried Ferrite cores yet.
Will do some testing and post the results.
So, no switching noises when it is connected to the grid ? Even when it is charging the batteries ?
Rising noise at lower frequencies is sure a common thing to see.
You may need to try a large-ish ferrite on the battery +/- cables. What happens to the noise when the DIY is inverting but the AC output loads are disconnected ? If search mode is active, you should disable it so it stays running and you can hear the noise.
If AC output wire is connected to a panel or power strips of something and noise is still there, try disconnecting the AC output right at the inverter itself. If noise is still there, disconnect the shore power connection at the inverter and check again, even if the shore power was not active.
All this is to try and determine which terminals the RFI is coming from. It might even be radiating from the unit itself but the box is kind of solidly covering the electronics if I remember correctly.
Also try to notice when you remove loads and wires if the noise gets better or not...
The last thing that I would try if only the battery is connected and the EMI is still there is to rely on the inverter's battery side capacitors to keep the inverter running for a few seconds after the battery is disconnected to see if it stops making noise during those few seconds that the battery is disconnected. That might give an indication that the inverter is radiating all by itself.
Also, are there any other communications cables coming out of the DIY inverter that might help radiate RF ?
PV connected ?
boB 🌜
... BUT. first, why not try switching the PV input to the inverter/charger > OFF <? Most likely, there is a circuit breaker on these leads, so, in a matter of seconds, one could discover what contribution this side of the box is contributing the greatest amount of RFI. boB knows much more than I, and perhaps, the 60 kHz spacing, might be much more linked to the HF inverter electronics, than to the CC side of things ...
Yes, in a camper setup, the PV cables are shorter than in most, larger stationary systems ... most of the HF interference that we have seen, does come from the PV cabling, and PVs themselves ... just sayin'
FWIW, whatta I know ?? ! ? 73, GL, Vic
Vic, I missed the part in his original posting regarding the solar.
Was assuming that it would not have been that because the EMI goes away when he is running on shore power.
But I should not assume anything there because the PV could be making things better or worse depending on his settings that determine when the PV will run
boB 🌜
When the camper is connected to shore power little to no RFI.
When the shore power cable is plugged into the DIY.
Inverter on - RFI on 80m is every 60hz
Inverter off â€" greatly reduced
Solar panels connected and charging - RFI on 80m is every 60khz.
Solar panels disconnected - greatly reduced
Unplug the shore power cable from the DIY and the noise is greatly reduced.
Cable lengths
Solar Panel cable 10'
Battery cables 2'
120vac cable to 30a plug 2'
So it looks like I need to put some sort of chock on the shore power cable.
I will have to try looping the cable.
I still have not figured out how to post pictures.
Quote from: Oldtimmer on May 18, 2022, 05:04:17 PM
When the camper is connected to shore power little to no RFI.
When the shore power cable is plugged into the DIY.
Inverter on - RFI on 80m is every 60hz
Inverter off â€" greatly reduced
Solar panels connected and charging - RFI on 80m is every 60khz.
Solar panels disconnected - greatly reduced
Unplug the shore power cable from the DIY and the noise is greatly reduced.
Cable lengths
Solar Panel cable 10'
Battery cables 2'
120vac cable to 30a plug 2'
So it looks like I need to put some sort of chock on the shore power cable.
I will have to try looping the cable.
I still have not figured out how to post pictures.
Sounds like you know what you are doing !
To post a picture, while editing, below the box you are typing in there is a "+Attachments and other options"
that you click on to upload your picture. Probably no need for a picture yet though because you are describing things very clearly for the moment.
How about at night when it is inverting.... PV connected vs. PV disconnected ? Then Shore power disconnected.
i.e. in the last case, all that should be connected to the inverter would be the battery wires and inverter AC output wires.
Sounds like the PV wires are certainly adding to the transmitting of noise.
boB 🌜
Reverified that there is no RFI on shore power.
Little to no RFI with the inverter on and the PV connected or PV disconnected.
Also checked with the unit pluged into shore power at the ac input of the MN3024DIY with the camper shore power cable unpluged little to no RFI.
Only seem to have a problem when the camper shore power cable is pluged in and looping the cable did nothing.
Thank you to all that have replied.
Jim
When you say you "looped the cable" earlier I assumed that you were looping it through a ferrite core of some sort.
What exactly does that mean ? 😁😁
Just 2 turns 12" loop of the cable real didn't expect it to work and it didn't.
The shore cable is almost 3/4" in diameter.
That would require a larger ferrite core.
I guess I need to run 10AWG threw metal conduit to the campers breaker panel.
Ordered a Split Core Ferrite, 18 mm, 200 kHz, 30 MHz.
Will see if it reduces or eliminates the interference.
Hi Jim,
When possible, twisting cables together can reduce conducted emissions, quite a bit. So, you might try twisting the shorepower AC conductors together, just several turns per foot, Then, do the same with the PV leads to the DIY, and see that result. And then, perhaps do a similar thing with the battery cables, if possible.
Twisting will effectively shorten these cables, and there is not always enough excess cable to do this.
Sometimes, having a few 2.4" OD toridial ferrites in type 31 materia (or, even larger outside diameterl, on hand can help. These have gotten more expensive than they were, but they can be arrows, in your quiver, for emissions-fighting.
73 Good Luck, Vic
A deferent issue on the DIY the PV output amps on the display reads about 3 amps higher then the battery amp input reads.
Other wise when the DIY reads 10A output the BMS reads 7A input.
Am I missing something here shouldn't they read the same?
I think that is MPPT out before powering any AC loads but I may be wrong
That is with no AC load inverter is off.
Can't believe that the DIY would take 2.5 to 3 amps to operate but it may.
Hi Jim,
There is another DIY Topic. There was some discussion here about Idle Consumption, FWIW:
http://midniteftp.com/forum/index.php?topic=5671.0
I know nothing, yet, of the DIY units, from personal experience.
Good Luck, 73, Vic
Well first weekend out dry camping.
MN3024DIY two thumbs up flawless operation.
DIY Lifepo4 24v 100ah Battery two thumbs up flawless operation.
PREDATOR 1400 Watt Inverter Generator - Connected to the DIY had to limit to 30a charge but worked grate.
Solar panels 335W 2 x 100W 1 x 135W not so good need more panels and mounted on the roof of the camper.
Did not take any radios this time out.
All in all things went well just need about 6 more panels and another 100ah battery and I will be set.
;D
Excellent news Oldtimmer !