diy solar

diy solar

DC Solar Trailer - LBM questions (newbie)

The midnight 250 isn't rated for 4kw of panels, but you should be seeing more than 2kw. I wonder if there is a limiter on the system somewhere.
 
I don't think SCC is programmed according to how many watts of PV is connected. Maybe output amps is adjustable.
The Midnight Classic 250 used on these trailers can handle up to 250 Voc (plus tolerate higher with HyperVoc), but output is limited to 63A.
That should still be more than 2000W, even though it wouldn't reach 3950W below 62.7V output. And of course current accepted by battery drops off when you hit absorption and CV operation.
Your panels and their angles & insolation probably don't reach the power you are expecting.
What are the panel specs, and what is the series/parallel configuration?
What are all the readings from Midnight display?
 
I don't think SCC is programmed according to how many watts of PV is connected. Maybe output amps is adjustable.
The Midnight Classic 250 used on these trailers can handle up to 250 Voc (plus tolerate higher with HyperVoc), but output is limited to 63A.
That should still be more than 2000W, even though it wouldn't reach 3950W below 62.7V output. And of course current accepted by battery drops off when you hit absorption and CV operation.
Your panels and their angles & insolation probably don't reach the power you are expecting.
What are the panel specs, and what is the series/parallel configuration?
What are all the readings from Midnight display?
I replied in the wrong place...sorry
Canadian solar 395k panels 43.3v x10
Wired in series. Two 5 panel arrays feeding into trailer
Max input from controller is full Mohave desert sun with 5% shade is 2k watts and 53 amps
Limit on controller is set to 90 amps---but you said max is 63A on the 250
 
Sounds like you are only getting one array (1975w). Did you check your wiring? I would unplug one string, and then the other.
 
Is that 43.3Voc or Vmp?
The Canadian 395W panels I'm finding vary, but are closer to 50Voc.
That would put you around 250Voc nominal for the string. HyperVoc probably protects SCC, but on a cold day in Hell it might not put out power.

Rich has an idea to consider, but if half disconnected I wouldn't expect you to get full 100% of 2000W rating of 5 panels except in very good illumination & temperature conditions.

What does Midnight report for PV voltage and current, battery voltage and current (or maybe its Watts in place of some of those figures)?
 
Most I have gotten on (4) strings of (5) 320 watt REC PV, in parallel, feeding (2) MS250 was 3100 watts peak on each MS250. You cannot get 62 amps at 250V, (read MS lit on that) more like 50 amps, also higher temperature lowers output as well. The MS250 is supposed to self limit output to about 3200 watts max but I've smoked one trying out (20) 320watt panels on one MS250 when sun came out full force. 320 watt (120 cell) panels are a good fit for the trailers, if arrays are pointed in different directions (east/south/west) you should be able to run (3) strings of (5) panels per MS250 and maximize what the MS250 can handle. And get the MS out of the DC cabinet if in a hot environment if possible they are only rated to 40C whereas the SI are 60C rated.IMG_1884 2.JPG
 
That enclosure looks like it would prevent cooling air from reaching chargers, if closed.

Not good to hear that a Midnight Classic hurt itself with either available PV power or temperature.

The DC Solar boxes don't comply with SI specs for clearance, plus are enclosed except for whatever exhaust fans. Probably recirculates hot air rather than drawing fresh outside into the bottom of SI.
 
We have one of these trailers for sale in our area, but a visual inspection only, it looks like the original batteries and I suspect they are at best on their last legs. What is a reasonable price for one of these things? It is the configuration “H”, no generator or light tower.
 
You can buy Sunny Islands new on eBay, some listed for $2500 (including delivery) recently.
2400W of PV panels, maybe worth $0.20 to $0.50/W
Midnight Classic a few $hundred
Homeline breaker panel, enclosure around everything, trailer.
All assemble, a bonus if you use it that way.
Probably requires 1 ton truck to pull, try to get delivered.
 
You can buy Sunny Islands new on eBay, some listed for $2500 (including delivery) recently.
2400W of PV panels, maybe worth $0.20 to $0.50/W
Midnight Classic a few $hundred
Homeline breaker panel, enclosure around everything, trailer.
All assemble, a bonus if you use it that way.
Probably requires 1 ton truck to pull, try to get delivered.
so 2 x $2000 = $4000 for 2 inverters
2400 x 0.375 = $900 for PV panels
Midnight charge controller $150
rest electrical: $250
trailer: $1500 ?
I think between $5000-$5500 would a fair price. (I paid way more for mine btw)
But you are stuck with a setup that isn't balanced. You will need to change stuff.
Why not start from scratch with something that is matched , you sized/built for your situation and that you can add-on to.
With what I know now, I should have never bought my trailer.
 
Thank-you both for the reply on fair market value. At $15,500 it seemed pretty steep especially knowing I've got a good sized bill in front of me for batteries.
 
That enclosure looks like it would prevent cooling air from reaching chargers, if closed.

Not good to hear that a Midnight Classic hurt itself with either available PV power or temperature.

The DC Solar boxes don't comply with SI specs for clearance, plus are enclosed except for whatever exhaust fans. Probably recirculates hot air rather than drawing fresh outside into the bottom of SI.
I don't close the door, it's inside a shed. I paid a guy $50 for the Aluminum panel box and just haven't pulled the piano hinge pin yet. But the MS 250s run much better when not hot.
 
The box with electronics, about half that. Waterproof, but more crowded than recommended space for cooling.


The inverters, $2500 delivered


Best setup would use Sunny Boy GT PV inverters rather than DC coupled SCC. (and add a load-shed relay especially for only AC coupled sources.)
 
Yeah, I know.
SMA stuff is designed to cool by convection, only running fans when needed. Fans last longer, and more efficient.
Manual says 12" sides and top, 20" bottom clearance.
In a box, the hot air out the top will recirculate in the bottom. "Carburetor Heat", I call it.
I would want to duct outside air in the bottom, with foam gasket. After leaves I don't care where it goes.
 
That enclosure looks like it would prevent cooling air from reaching chargers, if closed.

Not good to hear that a Midnight Classic hurt itself with either available PV power or temperature.

The DC Solar boxes don't comply with SI specs for clearance, plus are enclosed except for whatever exhaust fans. Probably recirculates hot air rather than drawing fresh outside into the bottom of SI.
I don't operate the (3) MS250s with the door closed, LOL, they do put out some heat. We bought a dozen of the DC Solar trailers are recondition them at our shop. Upgrades we can include are:
  • Reconditioned 540 ah batteries (2 year warranty from Battery service center)
  • New 320 watt (10) REC panels
  • New 380 watt (10) Canadian panels
  • New full 5 year warranty MS250 w/ follow me
  • Dual MS250s for up to (30) panel installation per trailer
  • Cabinet heating/cooling systems and air filter
  • Direct swap cabinets with SolArk 12K & LiFePo4 batteries (10-32 kWH)
  • DC Solar Cabinets with up to 65 kWH storage in them, to hang off the other end of a trailer, to eliminate the lead acid batteries.
 

Attachments

  • IMG_3609.JPG
    IMG_3609.JPG
    423.3 KB · Views: 12
  • 67459463663__538CDFDF-6926-477E-A929-8EF5522F36FA 2.JPG
    67459463663__538CDFDF-6926-477E-A929-8EF5522F36FA 2.JPG
    361.6 KB · Views: 13
  • IMG_4124 2.JPG
    IMG_4124 2.JPG
    300.6 KB · Views: 14
I have the same trailer. I have had good luck with it. I have 4kw of panels and the only issue is New charge controller goes into Hyper VOC. With cold mornings it runs 254v which exceeds the controller max of 250v.

You can add more panels but the charge controller will limit to 250v.
I know I could rewire the panels but for only 4 volts over I hate to. Trying to find a simple way to reduce voltage.

The orginal charge controller failed and I purchased a new one. Midnite has solid support.
 
I don't operate the (3) MS250s with the door closed, LOL, they do put out some heat. We bought a dozen of the DC Solar trailers are recondition them at our shop. Upgrades we can include are:
  • Reconditioned 540 ah batteries (2 year warranty from Battery service center)
  • New 320 watt (10) REC panels
  • New 380 watt (10) Canadian panels
  • New full 5 year warranty MS250 w/ follow me
  • Dual MS250s for up to (30) panel installation per trailer
  • Cabinet heating/cooling systems and air filter
  • Direct swap cabinets with SolArk 12K & LiFePo4 batteries (10-32 kWH)
  • DC Solar Cabinets with up to 65 kWH storage in them, to hang off the other end of a trailer, to eliminate the lead acid batteries.
I would like to hear more about your services available for these trailers.

Can I get direct contact info?
 
I would like to hear more about your services available for these trailers.

Can I get direct contact info?
Yes, our website is: OmegaSolarco.com my cell is 919 870 9987, our facility (Omega Solar LLC) is located @ 1516 Brookford Industrial Dr, Kernersville, NC 27284, 1/2 mile north of I-40 off exit 203

We carry most of the original parts for the DC Solar trailers in stock, but our focus is on taking the original concept much further and increasing their capability. We are getting ready to build mobile 10,000 watt gooseneck trailers with twin SolArk12K and up to 65kWH LiFePo4 batteries.
 
Back
Top