yesterday solar yeild was low..for a sunny dayToday about noon i open the bay to check the watt meterNO amps no voltage, display on the 2000e showed ZERO'sgrabbed the Fluke and read 20.00vdc OCV on the wires from the panelsopen the the controller and found thisthe burnt wires are the ones coming from the panel, and it is the black wire that got the hottest and burned and melted everythingNO loose connections, lugs and wire terminals tight, took some effort to break the screws loose and remove the wireswill be performing and autopsy on the controllerso i cut some wires pulled the controller and installed my backup Xantrex controlleri think i will be looking for a another controller at least 30 ampsthe xantrex is 40amp PWM, But has one 'quirk' i don't like, (when i tested it before) after 4hrs of charging it drops to float, even if the batteries are still absorbing at a higher ratewill see how it does over the next few days

It looks like the heat emanated from the screw terminals. So probably either the connection was loose (maybe the crimps) or they're just too small to carry the load.

Heat comes from to much resistance which implies poor connection or undersized wire or terminals. I suspect this didn't happen in one day. As I recall you have a good sized solar system with high current with parallel panels. Can't tell from the pic but the terminals if not the wire do not appear adequate.

Is it my imagination, or are many of the strands of the (formerly) black wire broken just above the crimp connector? If so, that's likely the cause of the problem—assuming things didn't get hot enough to melt or at least greatly weaken the copper, which seems probable to me. (Copper melts at a bit over 1000°C, though as is typical for metals it gets a lot weaker as it approaches the melting point.)

+1 on DrewE's comments. Crimps, wire, connection in general looks poor in hindsight.Is that 105C insulation? Resembles speaker wire more than solar.

Hi Mr Wizard,An unfortunate start to 2015 for sure!I'd go for 45 amps myself.

New Years Surprise, Burnt Solar Wiring | Good Sam Community

37 Replies

MrWizard
Moderator
Jun 16, 2015
they do NOT,
not with 505w i had installed
but it will be close when i have all three new panels connected

and the burnt wire happened at the terminal on the blue sky 2000e
not on the xantrex C-40 which is the controller presently be used
time2roll
Nomad
Jun 16, 2015
The panels should never exceed the ampacity of the connection to the controller.
Dead short all day should be fine.
MrWizard
Moderator
Jun 16, 2015
My system was not a kit

Yes there is a fuse, in the wiring from the panels
TechWriter
Explorer
Jun 16, 2015
MrWizard wrote:
. . . the burnt wires are the ones coming from the panel

Is there a breaker/fuse on these wires? If not, might want to add one.
Herk1952
Explorer
Jun 15, 2015
Were the components used in this installation part of a "kit"?
I am considering adding a solar panel installation to a Lance 1191 Truck camper and found this post from several years ago. http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/23873134.cfm. This installation looks top-notch, but I haven't seen the exact pieces in kit form, but all the components seem to be more than adequate for the job.
MrWizard
Moderator
Jan 03, 2015
Webpage said that was a C35
Not sure they got that correct
Mine is a C40, Xantrex PWM
AFAIK there are/were three versions of this controller
C35 does 12v or 24v
C40 12/24/48
C60 12/24
NinerBikes
Explorer
Jan 03, 2015
Wiz, what model is that the inside guts of? That back up Xantrex PWM unit?
MrWizard
Moderator
Jan 03, 2015
got a good solar yield today , better than i expected
79.18 Ahrs 1054.9 watt hrs

here is what the inside looks like
this is a web image, i did not take a picture of my wiring
time2roll
Nomad
Jan 03, 2015
Morningstar TS-MPPT-30 has terminals to accept #14 to #2 wire directly. No wire terminal needed.

Will also solve any charging profile issues.
MEXICOWANDERER
Explorer
Jan 03, 2015
General note...

Sometime when you have some free time take a look at how EURO TERMINALS are constructed