At noon today, noticed I’m not producing any power on a nice sunny day, with the battery at 92%.
Fine, maybe the SmartSolar Charger MPPT 100/50 is offline, failed? Nope, it on, no errors, so I can look at the history. Looked at the power generation graph and it abruptly stopped at 9:52am today.
Fine, power cycle everything. Nope, that didn’t do anything.
All the components (charger/inverter/batteries) are online and showing no errors.
Scratching my head, what am I missing?
A loose wire?
Bad switch?
Blown fuse somewhere (LD fuses are fine)
Did an extended power cycle (30 minutes) while in the grocery store, solar is back now.
But now I have an acrid electrical smell, so something is definitely not right.
At the time power dropped, solar voltage shot up, which would indicate the panels are delivering to the controller. Is anything else drawing 12V power right now, from the batteries - i.e. what are the readings on the battery monitor? What is the current path from charger to battery? Is there a voltage difference between the two?
Steve
No unusual 12V power draws at all.
I am seeing historical drops in wattage corresponding to voltage spikes. Is that normal?
At least I can rule out a fuse/breaker, as the power cycle wouldn’t resolve the solar outage. But turning everything off for 30 minutes does suggest the outage is related to an overloaded/overheating.
Something doesn’t smell right at all, turning off the solar panels until I can figure out what’s overloaded/overheating.
Yes, once the power output drops due to no current draw, the solar output will jump to the open-circuit voltage of the panels. Normal. The subsequent drops in solar voltage could be passing clouds or the sun partially obstructed by a leafy tree, etc. What I don't know with your hookup is where the solar charge output is directed. Even if the battery BMS's had shut down accepting charge, either the batteries or the solar charge controller should supply output to power lights, etc.
Note that batteries shutting down charge acceptance at less than 100% could be misbalance between batteries or a miscalibration of the battery monitor.
Steve
Looking at the state of charge at 9:52am, it was approaching 100%, so the shutdown makes sense, was normal.
What was not normal is from 11am onward until I noticed at noon, the battery power was being drained and solar charging did not resume.
The drain was using the refrigerator on AC, via the inverter, something I do everyday to conserve propane since the solar will keep up with the battery drain, bouncing between 100% & 99% throughout the day. Something kept the solar from keeping the battery charged.
Except for that hiccup, solar charging is working again, but that acrid electrical smell has me worried something is overloaded, given the smell dissipates with the solar charging turned off, that narrows down,
May have found the issue.
Opened up where AM Solar installed the batteries, inverter, and charge controller. Definitely where the acrid electrical smell was strongest.
Looks like the controller was hung on screws on the plywood wall of the couch pedestal, causing it to fall on what looks like bus connections!!!
Frankly surprised everything didn’t short out.
Going to put back the controller where it should be, see if I can secure it a bit more. I have driven some very VERY bouncy roads in Newfoundland.
Found the source of the acrid smell, the wires going into the controller that were on the exposed terminals.
Really surprised the controller is up and running!
Since the controller is working and there is plenty of cable, can I cut off the melted end, and reinsert?
That’s assuming the terminal isn’t damaged.
I see that two screws are now missing, which is why the controller fell.
Sloppy on AM Solar not to have plastic cover over that connection.
Scary! Good thing you smelled the problem.
I really wish Victron's products would accept ring terminals, instead of using those stupid "clamp the wire" setscrew terminals that can loosen, and are so close together that a stray strand can easily short things out.
Yes, I would definitely clean up and reterminate those burned cable ends. Scary they have the positive and negative connections adjacent!
Steve
Tips for cutting such a thick cable?
And for that matter, making sure the screws don’t come loose again, sealant, epoxy or liquid nails in the screw holes?
Hi Dave; I'm glad you found that. Sealant on the screws holding the controller onto the plywood, or some sealant on the controller so it doesn't fall off again. No sealant or thread lock or anything else on the screws holding the stranded copper cables. Those need to be clean and uncontaminated. The wire retaining screws are part of the connecting circuit, not just physically retaining the wire. The enlarged surface area of the threads decreases the amount of current per square mm passing through. Using spade type ring terminals, as Andy stated, is far superior, but costs more and uses up more real estate. Victron should enlarge that area. High currents are always going to dissipate heat at a connection, and the connections should be farther apart to avoid heat build up in one small area.
I think a small wire brush should clean up the copper involved in the connection. I would cut some of the melted and charred vinyl insulation out of the way. (don't nick or damage the conductors) I didn't see any arc marks or melted copper. I'd use heat shrink over the copper wires to cover where any insulation is missing. but without a good heat gun, use tape. My choice of tape is 3M Super 33+ available in black and red. https://www.homedepot.com/p/Scotch-Super-33-3-4-in-x-66-ft-x-0-007-in-Vinyl-Electrical-Tape-Black-6132-BA-10/304653556 You can use any tape in a pinch, but try to avoid the bargain stuff. If all the components are secure, you don't necessarily have to have the insulation at all, but not an optimum choice if that can be avoided. Tape will do for temporary repairs. RonB
edit: Pliers with a serrated jaw, or a file (jewelers file) can reshape copper terminals,; remove lumps of melted copper if present. A PM step to re-tighten screws involved with tight connections should be done routinely, as with the electrical panel, circuit breaker connections. RB
A PM step to re-tighten screws involved with tight connections should be done routinely, as with the electrical panel, circuit breaker connections.
At first, the acrid electrical smell seemed to be coming from the fridge area, so I opened up the panel to check all the connections, nope, all tight.
Boondocked at Walmart, across from a Canadian Tire & Home Depot in St John’s last night, to be near tools & parts, etc if needed today. Whoever inherits my LD will curse my periodic use of Robertson screws.
If I can’t salvage the Victron SmartSolar Charger MPPT 100/50, I’m hoping the only solar installer in St John’s has a new one, otherwise it’s going back to the dark ages (no solar) until I’m off Newfoundland.
Thanks for all the help Steve & Ron!
Tips for cutting such a thick cable?
Since you're right across from Home Depot, pick up a pair of cable cutters like the ones in the photo. They slice right through the copper strands and leave a nice clean end. Also, the yellow cable stripper is real handy for stripping large cables.
Whoever inherits my LD will curse my periodic use of Robertson screws.
I would love it. God bless the Canadian that invented the Robertson. Whenever I do any work on the LD I always replace those awful factory fasteners with Robertsons.
jor
Found the cable cutter, thanks!
Didn’t have a stripper.
Hi Jor; That Canadian might have been named Robertson. I have a larger version of that same cutter, good up to double ought, Probably 0000 too, but I haven't tried that yet.
I work on friends RV's too. First thing I do is rip out any Robertson screws and replace them with Phillips or Allen. Sometimes Torx. (special stuff). RonB
Hi Dave; Automated controllers for solar are nice; but you can substitute in a pinch with you! If you have 12v native panels (36 cells) hooked in parallel, you can hook them up directly to the batteries. Lithiums will absorb everything your panel can feed. It won't be very efficient, no MPPT action, but your wiring should be able to handle it temporarily. (not sure about the fuse). Definitely watch it, don't wander away. The BMS inside the batteries should protect things also. RonB
Rewired, but scratching my head.
The gauge wire used by AM Solar is too large to fit into the MPPT slots, so they removed strands until they fit. Had to do the same to reconnect, but not as sloppy.
I believe Victron accepts only up to 6AWG wires, and this is larger. So even if they used a larger gauge, it’s effectively no more than 6AWG.
It’s up and running, no smell, letting it run before closing up.
BTW, the cable cutter was worth the money spent, such a clean cut.
I have a larger version of that same cutter, good up to double ought, Probably 0000 too, but I haven't tried that yet.
Actually, that cutter does 00 with ease. I have even used it on 0000 but it takes some powerful squeezin'!
First thing I do is rip out any Robertson screws
Different strokes!!! ;D ;D ;D
jor
"God bless the Canadian that invented the Robertson."
I don't normally go about professing my ignorance but today is the 1st I've ever heard of this "Robertson" type of screw! So it's got a square head, big deal, many American screws can be had with the same style head. Is there something unique about the shank on the Robertson? What is it that makes it preferable to other brands? ::)
What is it that makes it preferable to other brands?
Nuthin'. :D Robertson was just the inventor. I think now it just describes the square head not the brand.
jor
Would have likely been the standard screw, beating out Phillips, if the inventor didn’t get greedy with Henry Ford.
Robertson Screw (https://en.wikipedia.org/wiki/Robertson_screw)
Robertson perfected the square socket. Definitely superior to Phillips, it’s the only common screw you can find here in Canada, everything else is an expensive specialty screw.
Traveling around the world and seeing the different ways things are constructed is interesting. Robertson screws are rare in the US, instead, our alternative screw type is the star or Torx head. Star head screws are usually used in wood construction for heavy-duty connections. I have seen a few Robertson screws for structural work at Home Depot but, checking now, I do not see any at this time at our local HD.
My favorite screw type is the Truss-Head Phillips Sharp Point Screw, they have large heads and drive well with the right size impact bit and rarely cam out. Any LD I worked on in the past will have them. They hold well in wood and sheet metal and are available in several lengths. I use the sharp point type and avoid self-drilling, except in sheet metal applications.
https://www.homedepot.com/p/Drive-Straight-8-x-9-16-in-Fine-Steel-Modified-Truss-Head-Phillips-Sharp-Point-Screws-1-lb-263-Pack-50294/100123027
Larry
My favorite screw type is the Truss-Head Phillips Sharp Point Screw
I really like those too. It was only recently that I started to use them regularly. I have to say that I too really like the torx head screws. The thing I like best about the Robertsons is you can really torque them down without the bit jumping out like its prone to do on a Phillips. Anyhow, we have lots of options when it comes to fasteners, that's for sure.
jor
Just realized that my Kreg pocket screw jig uses Robertson screws. Never had one of the Kreg screws strip out or break in hardwood.
Larry
Hi Dave; Losing some strands at the connector isn't all that bad. The bulk of the cable still has an overall lower resistance especially on long runs. Your connection integrity from whoever did your wiring is subpar! They should have done terminations with ferrules. https://www.grainger.com/product/PANDUIT-Ferrule-Bare-39AX51?opr=PLADS&analytics=FM%3APLA&a2c_sku_original=797UX7&position=1 There is even a crimper to make the ferrule square to fit in a terminal block screw terminal better: Pro'sKit 902-160 CrimPro Crimper for Wire Ferrules, AWG 2-4-6, Multi:... (https://www.amazon.com/ProsKit-902-160-CrimPro-Crimper-Ferrules/dp/B002PI6LU8/ref=sr_1_53?dib=eyJ2IjoiMSJ9.iJkBs5lJLwvhvpv9luzIn9dUCkuIFRSMzX8xS1-DJE6wMmfouf_nbE-0Jbqw_gmQ7Y3GtkGygIvI_MXpPXlqMXOV8nwap8GHkFLD8tiHcxDyUBF-E_mcVWOLIi1Ra6m2q0pAhU8WhnJ2wk489-CDaMTXooHxQLIAl_ibqU562Dnrfvydx0dxR-Kgax-FW6tNsKLTHu3Zgp0dhtVPkI0KIRV8n4Ifqf-1_HsP-xn9m1hmbGsT6cPEnseuIX57kbSBNZ0rtgtjlKQ3ZYD8zgikdaLh9oHYoAnfeYmevIsobXM.UCR4w4fmnjmS7TfuPDra4tPnhCKhLkz7xshv0f-ila0&dib_tag=se&gad_source=1&hvadid=694605905183&hvdev=c&hvexpln=67&hvlocphy=9031352&hvnetw=g&hvocijid=4403966458019744877--&hvqmt=e&hvrand=4403966458019744877&hvtargid=kwd-938365644426&hydadcr=29036_14670964&keywords=ferrule+square+crimper&qid=1721661672&sr=8-53)
Hand hydraulic (hex jaws) for larger cables: YUZES Hydraulic Crimping Tool 10 Tons 12 AWG to 00 (2/0),Battery Cable... (https://www.amazon.com/YUZES-Hydraulic-Crimping-Hexagonal-Electrical/dp/B0CFV249X3/ref=asc_df_B0CFV249X3/?tag=hyprod-20&linkCode=df0&hvadid=692875362841&hvpos=&hvnetw=g&hvrand=4473512075138570053&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031352&hvtargid=pla-2281435180778&psc=1&mcid=2e434e290a303febaf678f0772ef1ea4&hvocijid=4473512075138570053-B0CFV249X3-&hvexpln=73&gad_source=1)
Your installer should have used better methods and tools for a professional installation. RonB
That square crimper would have come in handy! I kept inserting the wire, see what strands didn’t fit, trim them, rinse repeat until it barely fit.
Despite the heavy char on the positive PV connector, the MPPT is working just fine, the connector still tightened up, no sign of extreme heat.
Still considering replacing it just because why risk the rig over a $400 part.
Thanks for all the help in get me up and running again, and a lively Robertson discussion.