diy solar

diy solar

Epever Tracer 4210AN max pv power input

I got 30 amp epever triron using panels with 1340w on 12! Volt batteries.
68v 20amp stepped down to 13. 8v 31 amps during float charge state lol.

Im not totally mad tho, i do have a switch to turn off half the panels for when its sunny and the panels are facing more towards afternoon sun/setting than south.


Oversizing for good performance when its cloudy and winter
 
An update to the post !!

I have 8 PV 330w mono 2s4p (in theory aprox 2kw) and 4210AN is working with limited current at 40A (69v * 15A = 1020w). So is working with more than 1kw panels, the condition is not to use more than 80v.
 
An update to the post !!

I have 8 PV 330w mono 2s4p (in theory aprox 2kw) and 4210AN is working with limited current at 40A (69v * 15A = 1020w). So is working with more than 1kw panels, the condition is not to use more than 80v.
Ya, the volt factor. Even 12V can make fire.

DC gets dangerous as volts go up- and it does or can do bad things over 50V.

I’ve sorta made it a rule to only run up to 85% of stated/rated capacity (even inverters) and stuff seems to last well not ‘pushing’ them. Even inverter cabling: if 10’ of 0-gage passes muster I’ll use 1/0. If a few panels ‘technically’ will charge with 10ga I’ll use 8. The cost difference in percent can be “a lot” but in dollars is often just two pizzas and you get safety and often, efficiency.
 
This thread looks as close as I will get to my problem, so looking for help with a similar problem. If anyone knows of a more closely focused thread please let me know. New at doing this so would appreciate guidance.
Situation:
Retired EE (I know how to make sparks!) in USA with 12v off-grid motorhome application with a 10kva Gennie driving a Magnum Hybrid MSH3012 (30a/12v inverter/charger) charging 6-100AH 12v AGM sealed house batteries wired in parallel. Recently added 2 EPEVER Tracer 4210AN chargers (c/w 2 MT50 meters) (each with own PV array) connected to battery bank in parallel, and 2400w (rated) of panels flat on roof (more on this later). Reason for two of each is redundancy.
Problem:
Plan is to use max solar to handle daytime high usage (appliances; lights; etc) and charge batteries to carry lower overnight refrig and latent load. Need 60-80 amps to do this. Chose EPEVER 40a Tracers because spec met/exceeded requirement cost-effectively.
SCC's function as expected under low sun - up to around 250w PV input (per MT50} producing 14-16 amps to batt each. As the PV input approaches 300w (285-290w as monitored by MT50) the charger output voltage becomes unstable (monitored with DVM) bouncing around 13-15 volts, and above, and soon as charge voltage hits upper limit (16.0v) the over voltage disconnect (OVD) locks out the SCC, and has to be manually reset. The 4210 Tracer specifies 520w rated charge power and 780w rated PV power - I am no where near either of these limits. Further, Voc is never above 80v.
During many test runs during bright sunlight I have seen this happen on both SCC's - both together and separately _ and cannot figure out what to do next. Since both SCC's are new, identical, set exactly the same, and exhibit identical symptoms, it is hard for me to see how it could be the SCC.
Forgot to mention that both SCC's are the new version that claim 'AUTO' voltage detection (12-24v) so no need to set to 12v. I have tried both AUTO an 12V settings to no avail. Occurred to me that there might be a way to lock the output to the 12v parameters but haven't been able to find any. Possibly it is a software issue?

Has anyone seen this phenomena or can shed some light on it??

Thanks in advance for listening

PaPaBob
 
Hmmm. So I re-read twice. Maybe it’s the ADD but did I miss how your panels are configured? Not saying that’s the issue but in my head I can’t ‘see’ your system.

And by “bouncing” 12-15V that bothers my head. I think capacitance is the correct term, but the ‘slow’ load of the batteries should be an adequate buffer for the potential float wandering of charge controllers. So in my mind the first thing up is, “bad connection.”

On the other hand, if your meter is somehow “too responsive” I can imagine the punches of the SCC might be readable? I don’t know.

As I said and you know: the batteries should buffer or dampen the V punches from the SCC.
Do the volts on the SCC display have similar fluctuations? Or just your meter? I can see how an unweighted meter output might not be steady just like measuring a msw inverter output shows 60V-170V or just 60V instead of 110V/120V like a true-sine inverter would. With good tight connections full batteries should read a steady DC voltage even though the charge controllers might be cyclic a little, punching the charged batteries with float.

Q? Will it do the same volt fluctuations with all loads disconnected? If so you’ll know it’s not anything cyclic on the load side.
 
Hmmm. So I re-read twice. Maybe it’s the ADD but did I miss how your panels are configured? Not saying that’s the issue but in my head I can’t ‘see’ your system.

And by “bouncing” 12-15V that bothers my head. I think capacitance is the correct term, but the ‘slow’ load of the batteries should be an adequate buffer for the potential float wandering of charge controllers. So in my mind the first thing up is, “bad connection.”

On the other hand, if your meter is somehow “too responsive” I can imagine the punches of the SCC might be readable? I don’t know.

As I said and you know: the batteries should buffer or dampen the V punches from the SCC.
Do the volts on the SCC display have similar fluctuations? Or just your meter? I can see how an unweighted meter output might not be steady just like measuring a msw inverter output shows 60V-170V or just 60V instead of 110V/120V like a true-sine inverter would. With good tight connections full batteries should read a steady DC voltage even though the charge controllers might be cyclic a little, punching the charged batteries with float.

Q? Will it do the same volt fluctuations with all loads disconnected? If so you’ll know it’s not anything cyclic on the load side.
Thanks for the touch-back -- I appreciate all the help I can get!

My PV array is series all the way (chose this to reduce current between PV and SCC). I have 4 identical new 210w rated panels on the roof but started with just 2 in series at first to be sure nothing was damaged - this gave me 420W rated (328w practical - they are flat) 35Voc measured in bright sun - and well within the SCC spec. Kept getting OVD so removed one panel so now have 210w PV rated (168w practical) and it will 'hang-in-there', but no where near the power I need. With just one 210w panel I'm getting around 14-16A chg at 13.2 volts.
When I reset and start up with 2 panels in series (328wp) and monitor PV with the MT50 and Vchg with my DVM I see +/- 295wPV and chg starts at 13.5Vchg and grows quickly to 14.2V @ 20A (which is my Charge Limit) then charges at this level for 30-45 sec, then Vchg starts to jump around from current batt voltage (lets say 12.6V) on low side to higher and higher on high side till is exceeds the OVD value of 16.0V (I assume) and locks out. Fortunately the SCC keeps the highest voltage it sees until reset so I can check - and over many test runs (like - 20-30!) I have seen anything from 19V to 32V. I have tried varying different Control Parameters slightly to see if any difference - none! Unfortunately, the SCC and MT50 only appear to refresh about once per 10 seconds so don't catch instantaneous changes.

I have come up with some possibilities.
1) SCC is faulty/damaged and just does not control behavior as expected. I'm doubtful of this since I have an identical SCC and have hooked it up identically, and got the identical result.
2)The SCC's I have are 4210AN 'AUTO Voltage' versions - senses whether 12V or 24V and allegedly picks the right one from the batt lead. Thinking that the SCC might get confused at 14.2V and start jumping around, then switch to 24V - how else to record a Vmax of 28-32V?? I haven't worked with 24V systems but thinking Vboost or Vequlz could be this high?
3) As I mentioned in my original post my plan is to have 2 4210AN 40A SCC's running in parallel (with separate PV arrays) feeding directly into my batt bank. I have wired both units in (but only working on one at the moment) using about 18" of #8 fine copper to a common post on a terminal/breaker block, then from there another 24" using a common #6 copper to the main +/- terminals of my on-board Magnum Inverter/Charger, which then goes directly (about 6') to the main batt terminals via #00 batt cable. Occurred to me that there might be enough resistance in this arrangement keep the batt from clamping the SCC charge voltage steady enough to stop the SCC charging without the Vchg jumping so high. I intend to run #00 directly from the SCC's to the batt terminals soon as I get back to my shop - travelling now and not something I want to do on the road!

Thank you for the thoughts on loose connections - anything can happen on a motorhome traveling on our roads, so I will go over all connections to be sure all are tight.
Not sure what you mean by 'load side'. The only load my SCC's see is the battery - my SCC load terminals are open (not connected) and the Load function is turned off internally inside the SCC.
My next move is to completely disconnect all other loads between the SCC's and the batteries (ie the I/C'er) and use the existing #00 battery cables between the I/C'er and batteries to attempt to eliminate the I/C'er from the equation.

Please let me know what you think on all this.

Thanks
PaPaBob
 
I need to make some business calls. But tonight or tomorrow I’ll read this over and respond. Or someone else will who is smarter than me.

by load I meant the battery (-ies). The batteries are sortofa load as well as a ‘dampener’ or shock absorber of sorts that stabilizes static readings (although using ‘shock’ regarding something electrical is probably inappropriate lol)
 
I have 4 identical new 210w rated panels on the roof but started with just 2 in series at first to be sure nothing was damaged - this gave me 420W rated (328w practical - they are flat) 35Voc measured in bright sun - and well within the SCC spec.
This is hard to follow. What is the spec on the panel label?
 
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