Crazy Weird No Volts?

Wanderman · May 2013

Hey All. Been testing my install from a year or so ago and I am having a VERY weird issue.

Today, I went inside the RV at Noon and the Morningstar TS-45-MPPT remote (RM-2) is showing zero volts and zero amps (NIGHT).

I reset everything, and then went up on the roof. At the junction box, 1 for each panel with a diode inside. Since I have a positive and a negative going from each panel then into a fuse panel. At the panel I have ZERO volts!

I have 3 panels, NONE of them show any voltage. ***? Could they ALL have failed the same way, at the same time?

Help!

Rich

niel · May 2013

Re: Crazy Weird No Volts?

can you pull the wire for the individual pvs in the combiner to confirm each are not producing any power? better yet check at the pv mc4 connections. if all 3 pvs failed i might suspect a diode problem inside of the pvs, but other than that i would be at a loss as to what may have caused 3 to fail. one can speculate.

Wanderman · May 2013

Re: Crazy Weird No Volts?

There is no true combiner, except at the fuse panel by the MPPT charger, On the roof, at the box mounted on the panel (one on each box) I have no volts at all. This is directly measured at the panel outputs on the roof.

Worked yesterday, fine. And the last 60 days of Morningstar log is fine and dandy.

Rich

BB. · May 2013

Re: Crazy Weird No Volts?

Starting at the panels, disconnect all wiring and measure Voc (voltage open circuit)... You should see >20 volts (assuming Vmp~17.5 volts or so for panels) in almost any sun (overcast or clear sky).

If you see ~20 volts or so, then set the meter for 10 amps full scale (assuming Isc of panels is less than 10 amps) and attempt to short out the panel (cover panel with blanket or cardboard if sparks bother you) and measure Isc... In full near noon time sun on a clear day will panel pointing squarely at sun, you should see 50% to 100% of Isc.

Then go on from there.

It is slightly possible panels failed one at a time until the last one failed and left you with ZERO volts/amps... But it seems to be unlikely. Normally there would be at least enough of an internal connection for you to get something on the meter.

You could have shorted bypass diodes. With the panel in the dark, you set your meter to "Diode Check" and see if each bypass diode shows a "conduction/blocked" direction.

-Bill

Wanderman · May 2013

Re: Crazy Weird No Volts?

I am going down to test that now, but shouldn't I see voltage whether or not it's connected downstream from the panel??

Rich

BB. · May 2013

Re: Crazy Weird No Volts?

Just fault isolation--You can start where ever is easiest.

If you have a DC Current Clamp meter, it would be really fast to clip on each wire and determine if there is current flow or not (short=current flow, open=no current flow).

-Bill

Wanderman · May 2013

Re: Crazy Weird No Volts?

As usual I am dense.....

If I put test leads (pos/neg) on the panel itself, regardless of whether it's connected downstream, shouldn't I get some voltage? If I have no voltage how could I have any current?

Rich

Cariboocoot · May 2013

Re: Crazy Weird No Volts?

Wanderman wrote: »

As usual I am dense.....

If I put test leads (pos/neg) on the panel itself, regardless of whether it's connected downstream, shouldn't I get some voltage? If I have no voltage how could I have any current?

Rich

Yes, and as per Niel's and Bill's suggestions that's where you start: disconnect ever panel and check each one for Voc. Then check each one for Isc. If you haven't got either the panels have, for some reason, failed.

What are the panels, btw?

Wanderman · May 2013

Re: Crazy Weird No Volts?

They are the custom semi flexible panels I ordered from china a while back.

See this thread: http://forum.solar-electric.com/showthread.php?10006-Balanced-MPPT-system/page11&highlight=wanderman

for info and pictures.

I looked VERY closely at the panels themselves and can see no breaks in any leads or modules.

They have a junction box affixed to the upper side of each panel with a blocking diode on the positive terminal . Each one has it's own independent neg/pos pair going down to it's own fuse (positive side) and neg stud. From there it goes to the morningstar.

This was working YESTERDAY. And the past 60 days of log from the controller shows normal volts and amps. I am at a loss. I have no idea what to try at this point and removing these panels will be VERY difficult to do.

We did have some strong rain yesterday, but all the junction boxes are dry inside. It's frustrating to see the controller show NIGHT in the middle of the day.

I was just testing. I removed the positive lead from the junction box terminal and tested volts at the panel's pos/neg leads. Nothing at all. On all three panels. What are the odds? I tested before and after the diode AND for amp both with a direct connect and a clamp on. Nada.

Seems to me it's a wiring disconnect, likely the same place or similar on all three, but where?

Sent an email to the manufacturer....maybe they will reply.

*sigh*

Rich

niel · May 2013

Re: Crazy Weird No Volts?

you state that you have blocking diodes in place so i would suggest going into at least 1 of the panel's junction boxes and measure on the pv side of that diode to see if the diodes themselves may have failed and leave it disconnected from the rest of them to be sure of no other draws or shorts downstream. if you still get nothing then you have a problem and it's hard to say what may have gone wrong to pop all 3 pvs. very unusual.

KnowledgeSponge · May 2013

Re: Crazy Weird No Volts?

Wanderman wrote: »

They are the custom semi flexible panels I ordered from china a while back.

See this thread: http://forum.solar-electric.com/showthread.php?10006-Balanced-MPPT-system/page11&highlight=wanderman

for info and pictures.

I looked VERY closely at the panels themselves and can see no breaks in any leads or modules.

They have a junction box affixed to the upper side of each panel with a blocking diode on the positive terminal . Each one has it's own independent neg/pos pair going down to it's own fuse (positive side) and neg stud. From there it goes to the morningstar.

This was working YESTERDAY. And the past 60 days of log from the controller shows normal volts and amps. I am at a loss. I have no idea what to try at this point and removing these panels will be VERY difficult to do.

We did have some strong rain yesterday, but all the junction boxes are dry inside. It's frustrating to see the controller show NIGHT in the middle of the day.

I was just testing. I removed the positive lead from the junction box terminal and tested volts at the panel's pos/neg leads. Nothing at all. On all three panels. What are the odds? I tested before and after the diode AND for amp both with a direct connect and a clamp on. Nada.

Seems to me it's a wiring disconnect, likely the same place or similar on all three, but where?

Sent an email to the manufacturer....maybe they will reply.

*sigh*

Rich

If you disconnected and isolated ALL 3 panels, then tested each one by connecting your WORKING VOM to the positive and negative leads at the panel, then failed panels is the only thing I can think of. Maybe you exceeded the current the panels could handle and there was damaging current across all three panels at the same time. Or maybe the CC failed and backfed the panels?

Are you SURE your VOM is working properly?
Are you sure there is sun on the panels?
Are you sure there are no additional grounds that could be bleeding off the current somewhere?

These are WAGs. others will have more useful replies.

niel · May 2013

Re: Crazy Weird No Volts?

KnowledgeSponge wrote: »

If you disconnected and isolated ALL 3 panels, then tested each one by connecting your WORKING VOM to the positive and negative leads at the panel, then failed panels is the only thing I can think of. Maybe you exceeded the current the panels could handle and there was damaging current across all three panels at the same time. Or maybe the CC failed and backfed the panels?

Are you SURE your VOM is working properly?
Are you sure there is sun on the panels?
Are you sure there are no additional grounds that could be bleeding off the current somewhere?

These are WAGs. others will have more useful replies.

one cannot come a conclusion quite yet even though it is not looking good at this point as the blocking diodes may be blown.

i trust that what i have bolded does not mean that he has not gotten good help up until now.

Wanderman · May 2013

Re: Crazy Weird No Volts?

Looking pretty bad so far. I pulled the three fused (one for each panel at the box near the charge controller) Up on the roof I opened each junction box and tested (with TWO working meters) each positive and negative flat lead. Both ahead and behind of the blocking diode. I am seeing no volts at all. This was during the day in full overcast sunlight.

I am still hoping there are bad connections under the junction box. The flat tabs don't look all that sturdy after they emerge from the panel itself.

I had someone offer that they were "flexed: to far, but I don;t think that would be the case with all (or any) of them. In fact the front one (170 Watts) isn't flexed at all.

The more I think about it, they may not have all failed at once, since I am rarely using much battery power, the controller rarely puts out full amperage even when it's available. I could have been on a single remaining panel and that one finally dies. The odd thing about this? The RV had been parked for well over 2 months, so no vibrations nor harsh conditions. I am thinking some water ingress someplace, leading me (hopefully) back to the junction boxes.

If you are interested, there is a six part article about the research, design and install here:

http://www.thewanderman.com/2011/11/better-solar-charging-mouse-trap-part-1.html

I hope I can resurrect these panels. It would be a mess to have to remove them and expensive and would ruin my only vacation like escapes for this season.

Kind of depressing.

Thanks everyone,

Rich

BB. · May 2013

Re: Crazy Weird No Volts?

You have disconnected any wires to the panels? A short in the downstream wiring harness would also reduce the output voltage to near zero too.

-Bill

Wanderman · May 2013

Re: Crazy Weird No Volts?

Bill,
I believe I disconnected everything downstream. I will go back out and isolate the panel both neg and positive. I believe I just removed the positive terminal last time I checked them. I also removed the fuses that feed the panel voltage to the controller. It's raining now, so there's not much I can do except be depressed about the whole issue.

Thanks,

Rich

waynefromnscanada · May 2013

Re: Crazy Weird No Volts?

Well if you disconnect the wires from the panel and then get nothing when checking output at the panel terminals, then I'd be depressed too

Hopefully this will not be the case, but from where we sit, things don't look good at the moment.

BB. · May 2013

Re: Crazy Weird No Volts?

In the dark, use an ohm meter set for ohms, not diodes, and look for shorts from array to the metal skin + structure of the rv.

-Bill

niel · May 2013

Re: Crazy Weird No Volts?

i guess ultimately you may want to remove a pv and bring it down to verify good or bad. in the meantime with all of the rains coming down you may wish to revisit buying pvs again.

check here for possibilities,
http://www.solar-electric.com/solarpanels.html
also, some posters have obtained 12v pvs i believe from dm solar if you find none in the naws section fit.

Wanderman · May 2013

Re: Crazy Weird No Volts?

OK.. I spent some more time up on the roof. I have found some corrosion under the junction boxes, but even using a needle probe to touch the traces underneath the membrane I am unable to get a voltage reading above millivolts.

I am on the hunt for new panels. I prefer the frameless concept, and adhering them across their entire surface with a paralastic adhesive worked well for keeping them on the roof at speed. There are no breaks in the modules at all, the problem is more likely bad workmanship on the solder jointsa coming loose due to vibration.

The main issue I had when first looking to purchase panels was the small spaces I have on the roof to accommodate the panels. Here is a picture/map I made illustrating the issue:

Attachment not found.

The panels I have now, were custom made to fit the largest spaces I had on one side, so I could park minimizing shadowing.

Attachment not found.

You can just barely see the front/center panel which is much more square (around 42" or so) The rear right side goes all the way to the edge with about 1.75" left.

They total 450 Watts, that was plenty of power for my use with a large margin for bad weather/shading, etc. I'd like to keep the same or greater watts. The main issue I have is the space. The narrow ~26.5" on the right of the A/C unit is tough.

All the panels were 36V nominal (around 41 or so VOC) I have a Morningstar TS-45-MPPT that can do 150V max input. I did well with the 36V ones.

Any ideas? Help, recommendations. I am in Semi-Upstate New York. There is a Sunwise factory nearby, but I don't know anyone there that I could convince to make me a custom size.

This couldn't have happened at a worse time. I only get around 3 months of decent weather here in the Northeast, and I will have essentially no power for camping. The 2 Group 27's are fine for an overnight+ but relied upon Solar to top off in the morning. The generator is not efficient nor quiet at all.

Please help, it's the only "vacations" I get all year.

Rich

westbranch · May 2013

Re: Crazy Weird No Volts?

a Honda Eu1000i comes to mind as a cost effective alternative.

BB. · May 2013

Re: Crazy Weird No Volts?

I too fear that a Honda eu1000i (~$700 or so???) is going to be the best short term solution. It will only cost you a gallon of gas per day if you use it a lot--And they are not loud (get a 100' extension cord if the noise/fumes bother you that much).

Around 3.8 to 8.3 hours per 0.6 gallon of gas (900 watts to 1/4 power or 225 watts).

I have seen more and more RVs with solar panels setup as awnings on the side of the RV (some pretty big installations).

A pair of ~200+ watt panels at ~$250-$350 each (plus $hipping and handling) or 4x 140 watt panels at ~$250-$300 each (plus shipping). You already have a 45 amp MPPT controller--So any of these upwards of:

45 amps * 14.5 volts charging * 1/0.77 array+controller derating = ~847 watts

...would be very cost effective (with existing MPPT controller).

Having panels on the side of the RV does expose them to more damage--But they probably will cost you less to replace if the worst happens.

-Bill

Blackcherry04 · May 2013

Re: Crazy Weird No Volts?

I wouldn't underestimate what expansion and contraction could have done to the panels internally having them glued down on the roof. You'd also get buffeting from the wind while at road speeds.

Wanderman · May 2013

Re: Crazy Weird No Volts?

That defeats the entire purpose of going solar. Last year I never ran my generator to charge batteries. And only twice for AC in the middle of the day.

Now way, Solar is the way to go!

Rich

BB. · May 2013

Re: Crazy Weird No Volts?

I forgot to add a link to our host's >100 watt panel web page:

http://www.solar-electric.com/hiposopa.html

You can look through those panels and see if any of them look "interesting" for mounting on an aluminum awning type frame. Put on the "door side" if you want shading for a "patio"... Or on the far side if not (do you have a slide out--could be an issue).

I don't remember what you paid--But these are probably pretty cost effective solutions overall when you add the costs for the hinged/locking awning frame(s).

-Bill

Wanderman · May 2013

Re: Crazy Weird No Volts?

Guys, I am NOT mounting them on the side. They will replace the ones I have now, hopefully in the same spaces.

The 3M Paralastic adhesive has enough give that it actually reduces the vibration. You easily see that the panels aren't cracked nor ae the traces broken. This is much more likely a corrosion matter. That and bad solder joints internally. MANY people have had more success than I.

Rich

BB. · May 2013

Re: Crazy Weird No Volts?

Rich,

How long of life would be "good" for your panels?

I tend to suggest ~2 years maximum for flexible panels glued to a structure (popular for sail boats and other non-flat structures).

And up to 10 years for non-glass and otherwise good quality panels.

If you need >10 years--Then you are probably looking at glass based panels. You can buy frame-less glass panels (be very careful of dinging the edges of tempered glass) and possibly gluing them down on a "thick" layer of silicon type 2 (or other silicon designed for electrical circuits, the standard silicons set using acidic acid type compounds--vinegar).

If you have too thin of adhesive layer--Then the aluminum/structure of the RV has too different of coefficient of expansion with the glass/silicon panel and will just attempt to delaminate everything.

But--even so, I am still wondering what did fail so completely (and on three different panels at the same time) that you cannot even pull a few volts out of them. It tends to suggest that there is a fundamental flaw in the design/installation somewhere for it to happen so quickly and on three separate locations at "the same time". And that you have not found the failure yet--That is just strange.

Look closely at the panels through the clear top... Do you see any bubbling, delamination, brown spots, black spots (overheating), or white spots (possible water/air/moisture intrusion)?

As to alternatives--What do you think would be acceptable? I am kind of running out of ideas here...

-Bill

Wanderman · May 2013

Re: Crazy Weird No Volts?

Bill,
Been looking at them quite closely. I do believe they failed sequentially rather than simultaneously. How long an interval between them is unknown. The roof is fiberglass, free floating on the steel ribs underneath. The only oddity I can find with the panels, is a small amount of corrosion at he junction box solder tab leading into the membrane to the traces on the panel. I have attempted to bypass this and tap directly into the trace on the panel itself, but so far, no dice.

I agree, this kind of failure shouldn't have occurred. The manufacturer insisted the glue down method was fine and with an aluminum base on a fiberglass roof the heating wasn't bad at all. Well within the tolerances given for the panels. They knew it was to be mounted on a vehicle and stated clearly that it was OK to do so.

It may turn out that the problem is surmountable and all will be well. Who knows?

In the mean-time I am looking for panels that will fit in the same spaces on the roof and give me at least 450 watts. As efficiently as I can find. Preferably in the US.

Rich

niel · May 2013

Re: Crazy Weird No Volts?

do those pvs have a warranty with them? if so and they gave you the green lite on the install then they should make good on the replacing of your pvs. i'm not sure even if replaced that your problem will go away as it is bound to reoccur and they won't approve the install the 2nd time around.

Wanderman · May 2013

Re: Crazy Weird No Volts?

Niel,
While I could be wrong, even though I have a 10 year 90% output guarantee, collecting will likely be impossible. Even though they are a reputable manufacturer....they are in China.

Hence my request for US sourced panels that fit the measurements I need.

Rich

NorthGuy · May 2013

Re: Crazy Weird No Volts?

Wanderman wrote: »

While I could be wrong, even though I have a 10 year 90% output guarantee, collecting will likely be impossible. Even though they are a reputable manufacturer....they are in China.

Still, it won't hurt to contact them. It's quite possible they may do something.

Wanderman · May 2013

Re: Crazy Weird No Volts?

Already done

Still, I like to have myself covered. The sooner I find an alternative the better off I will be.

Rich

Crazy Weird No Volts?

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