Burned front canvas

[muttmaster]

Noticed two purplish marks on the front of the my Grandby canvas, driver side just begins the strut last week. Peeked behind the front panel with roof dropped half way and saw burned marks. Cursory look at the wiring front the solar panels but due to confined space, couldn’t tell if the wires were burned or frayed.

I contacted 4WC and Stan and the service dept. suggested that my 280 watts in the roof may be too much for the 10 gauge stock wiring, and I shouldn’t go over 160 watts that the Grandby came with.

I have read here many campers have much more higher wattage panels on the roof and I never heard that over 160 watts may be a fire hazard.

Has anyone else had this problem and what I can do to repair the burn marks? Now if only I can figure out how to post some pics…

 

[Vic Harder]

330w here, but I did run my own wires. Are your 280W being created by one panel or more? Wired in parallel or serial? If parallel, the current would be higher...

 

[pvstoy]

480 watts here in parallel. Have not noticed anything.

 

[Charlie]

350W here in series. Series/parallel installation is relevant.

 

[TacomaAustin]

Did the repeated folding of the wires at the roof's front lifting hinge cause a number of strands within one or both wires to break and cause a higher resistance when the full number of amps are plowing through the circuit?

 

[Jon R]

400 watts from two parallel 200 watt rigid Renogy panels and a Victron SmartSolar 100/30 on my Grandby. I have not seen more than about 23 amps on the panel input side to the MPPT when the charging output is at the full 30 amps. The 10 awg FWC panel wiring should be good for 30 amps without excessive heating according to the wire charts. If you have an MPPT controller and 280 watts of panels in parallel you should be well under 30 amps on the panel circuit.

TacomaAustin may very well have the answer above.

 

[Wandering Sagebrush]

Did the repeated folding of the wires at the roof's front lifting hinge cause a number of strands within one or both wires to break and cause a higher resistance when the full number of amps are plowing through the circuit?

I think this is what happened, there have been a number of broken wires at the lift panels.

 

[muttmaster]

Hi Vic,
I had stock 160 watts and then added 100 watts in the back. Initially, I had the 100w connect thru the rear plug for several years without issue expect the “unclean” look of dangling wires off the back. Late last year, I got a 180w Bouge RV panel for the middle and added the rear 100w thru splitter. No prob until last week. I guess it is parallel.
What gauge solar wires did you use? Should I upgrade or is it too much of pain fishing thru the roof, and I probably have to upgrade the receiving plug too?

Meanwhile, I unplugged the 100w in the back for now and I really may not need it until Winter anyway. I have the 100w on a tillable mount and it has helped quite a bit around Winters Solstice.

 

[muttmaster]

I think this is what happened, there have been a number of broken wires at the lift panels.

 

[muttmaster]

Thanks Sage and others for very quick replies. I will check the wires this weekend throughly.

Service Dept at 4WC emailed me and specifically indicated that the roof plug is designed for up to 160 watts max. Probably a off the shelf…what is the legal term for: we are not responsible for any watts over what we have in stock configuration.” May be they should “warn” or advise owners.

 

[muttmaster]

400 watts from two parallel 200 watt rigid Renogy panels and a Victron SmartSolar 100/30 on my Grandby. I have not seen more than about 23 amps on the panel input side to the MPPT when the charging output is at the full 30 amps. The 10 awg FWC panel wiring should be good for 30 amps without excessive heating according to the wire charts. If you have an MPPT controller and 280 watts of panels in parallel you should be well under 30 amps on the panel circuit.

TacomaAustin may very well have the answer above.

 

[muttmaster]

I have VictronConnect 30amp controller and LiFo4 200 ah battery. System worked very nicely and I had no issues until last week. I will check wiring and will report back if I find frayed wires. Thanks very much to all.

 

[Wandering Sagebrush]

If the burns are through the material, I’d patch it. If not, use some 303 on the area. Watch for leaks.

 

[muttmaster]

It is not burned thru. It is scorched pretty toasty on the inside. Two spots like a inverted comma about 3.5 inches. Probably happened when the top was down as the spots sort of matches in shape. Lower scorched spot is more dark and deep compared to the spot on top.

 

[Vic Harder]

I'm thinking JonR has it right, frayed wires.

 

[Jon R]

I'm thinking JonR has it right, frayed wires.

The good suggestion that it could be broken strands from bending leading to wire overheating came from TacomaAustin.

 

[ckent323]

I also suspect that Tacoma Austin's suggestion is the most probable. Broken and/or pinched strands in the 10 gauge wire.

Jon R is correct that 10 gauge wire is rated for 30 A constant current and that the current from 280 W of solar should be well under 30 A.

 

[Helmut]

Had the same problem. The weak point was the (poor) crimping of the wires behind the folding panel. They had turned black and melted the insulation. Also the port in the roof had melted/cracked over time. Maybe also due to UV rays and environment. Not all of the wires are 10, some are 12. So I changed to a mppt controler and installed the panels in series. Max amps dropped from 24 to 8. Checkin regulary now. So far (two years) no further problem.

 

[Jack]

My bets are also on broken strands. As to the SAE connector "rated at 160W" - get rid of it and replace it with an MC4 cowling with two pigtails. The SAE connector, if not under a panel, will rust out. Do not get an SAE cowling with plugs - your break the seal if you have to unplug the cables.

 

[muttmaster]

Sorry Gents,

It has taken too long for me to finally have enough energy to check for frayed solar wires due to health reasons.

I just checked the red wire solar input behind the front panel. Wire connector near the scorched fabric felt warm/hot. The crimped on connector looked burned a bit and I did not see any frayed wires. I did not see any other sections of the wiring where it could be frayed from repeated up and down actions of the roof panels, but I will try to have better look at it soon.

For now, I just taped the burned connector repeatedly and will replace with new one next time. I am thinking about what else I can place around that area to insulate it and prevent future fabric scorching. Something thin, with high heat tolerant material that is cheap and easily taped on around the panel and connector. Any suggestions?

Thanks for all the suggestions from my initial post.