made a mistake

wellbuilt

 I made a mistake wireing my solar panel Combiner box I accidentally wired three panels backwards and pop the  mid nite 15 amp breaker ,  now I don’t seem to be getting any power from that string . 
 Do you think I blow the breaker of did I Ruin three 295 watt panels ? Help

wellbuilt

 No opinion .?

westbranch

HAVE YOU GOT A GOOD MULTI METER TO CHECK THE pv OUTPUT? OOPS not shouting , CAPS was on...

wellbuilt

I’m  screaming  enough my self , I was trying to get it hooked up last night in the dark and just missed the +- on the plug and did not notice it I turned on the breakers this morning as I was coming out of sleep mode and it popped with 50 watts on it . I thought I had this nailed down .  My meter is missing for the moment 

Estragon

Reverse polarity maybe (hopefully?) triggered protection in the controller?

wellbuilt

I have to leave to go home ,  The controller is working fine with the other four strings of panels , 
 the breaker popped in the  combiner box  

Estragon

Next thing I'd check would be mc4 connectors.

wellbuilt

I reversed the mc 4 Connections at the panel after the breaker popped I changed the mc4 connectors but don’t seem to be getting out put from that string . 
 The breaker stays on but no out put at the controler .
  Don’t have a meter with me , and don’t. Know for sure how to read the meter for PV out put .

mike95490

Breakers are not supposed to die after 1 activation, unless they are something like household AC breakers on a DC circuit.

wellbuilt

Hi Mike breakers where 15 amp pv breakers

Vic

Hi wellbuilt,

In looking at this previous Thread:
http://forum.solar-electric.com/discussion/353404/solar-panels-for-48-volt-battery-charging#latest

You said that you have 24 PVs,  arranged into strings of three PVs.   But   it seems that you were only running five strings when this event occurred.     There could have been  the Isc that was available at the moment that you closed "the breakers"   (assume these were the Combiner breakers),   that the Isc total of the strings that had their breakers closed would be available to be dumped into that one reversed string.   This could have damaged the Bypass Diodes in the PVs of the reversed string.

The Bypass Diodes are almost always located in the junction box,  on the back of each PV  --  where the PV's cables attach.

Breakers in combiners are there to protect the PVs and the cables attached to the PVs from overheating (and fire),   in events similar to this ...

Breakers operate fairly slowly.   Their response time varies by the amount of current flowing through them.

Assume that the "mid nite" breaker  WAS an MNEPV DC-rated breaker.   There should be no damage to this breaker from this event.   When you have access to a meter (perhaps a neighbor?),   you can check the voltage from that string in full sun,   and disconnect each PV on that string to measure each PV,   etc.

Just a drive-by comment.  Good luck.   Vic

wellbuilt

Hi Vic thank for the advice , but I did this to my self I Wired this set of panel backwards,  I was rushing to get done before it was pitch black . 
 Life got in the way of my installation and had to leave it sit for 4 weeks , 
 the breaker looks burnt on the out side . 
 When I look at the back of the panels there is a box full of epoxy of some type I can’t see any diods
 do you think I’ve burnt out all 3 panels or just one .
 I tried a difrent string on the breaker but there was no out put ?

BB.

Just measure Voc and Isc for each panel and see what you get. Even if one or more panels test OK--They could still have been weakened and prone to early life failure... (and find the meter).

A reverse installed panel--Just a "forward biased" diode that will take all the current it can. Presumably, Imp or Isc forward current should not kill a panel--But 3x Imp/Isc is P=I^2R -- So 3^2 is 9x more "heating" in the panel and interior wiring--Much more heat in the reversed panel than designed...

-Bill

petertearai

burnt breaker ... sounds like breaker is caput. Was it a dc breaker ,  If no meter  i would replace breaker ( if you have one)  for a start .

mike95490

If the breaker is burnt, it was the wrong kind and the vendor owes you a replacement.

Unless you used a 24V breaker in a 48V application

wellbuilt

Vic

wellbuilt said:

Hi Vic thank for the advice , but I did this to my self I Wired this set of panel backwards,  I was rushing to get done before it was pitch black . 
 Life got in the way of my installation and had to leave it sit for 4 weeks , 
 the breaker looks burnt on the out side . 
 When I look at the back of the panels there is a box full of epoxy of some type I can’t see any diods
 do you think I’ve burnt out all 3 panels or just one .
 I tried a difrent string on the breaker but there was no out put ?

OK,   it the breaker has signs of being burned,   for the zero-output string,   then,  that breaker is now,  probably bad.

Please tell us about the Combiner  --  is it commercially made?  What brand is it?  What breakers are installed in the Combiner?  Are the DIN Rail type?

For MidNite,  and Outback Combiners,  it is very difficult to wire the breaker backwards,   but,  guess that it could be done.   The MNEPV breakers (and Outback's as well)  ARE polarity-sensitive,   and need to be mounted vertically,  with the output busbar up.   The Combiner can be mounted on a sloped roof,   but,   IIRC,  there is a limit on how flat the roof slope may be.

If you have any interior pics of your Combiner,   the burned breaker,   etc,   that you could post,   that could help us.

Thanks,   Vic

wellbuilt

Type your commentthis is what I have 

wellbuilt

wellbuilt

 I wired 9 panels 3 sets of 3 295 watt and ran the wires to the combiner box and had it all done buy 930 
  700 am I was waiting for some sun , I turned on the CC breaker then the pv breaker .
  I started getting 60 Watts the CC woke up and went into bulk charge with my first 2 strings of panels 800 am maybe 
  I walked out side and turned on the first new string of panels and it sizeled 😬 I turned the breaker off buy hand it did not pop . 
I then walked inside saw 130 watts coming in and turned off the pv . 
 My I made a mistake and wired the panel plugs backwards . 
 I swapped the plugs on the2 strings and they powered up fine . 
 The third one won’t power up .( this is the one that the breaker popped on ) 
   I bought 2 new breakers like in the pic above  
 I tried the damaged string on a good breaker but there was no out put . 
 So I will replace the panels with 3 other panels I have , but are my  panels dead now ? 
  They have epoxy or some kind of sealer over the diodes ? 
  Ive been trying to work up at the house every other weekend but we’ve missed a month now 
 and the snow is coming 

Vic

Thanks wellbuilt,

That Combiner does look like a MidNite  MNPV6,   BUT,  the Negative busbar on the left  has white insulators,   and all of the MNPVs that I've seen uses black insulators on the left   ...   That box does not look large enough to be an MNPV12,   which you would need if you have eight strings,   unless you are using a second combiner.

Do you know the manufacturer and model number of the Combiner?

More later,  Thanks,   Vic

wellbuilt

Yes it’s a mid nite mnpv6  I have 5 string run in to it .
 Will ground mount the other 9 panels on the ground in the next few years . 
  Do you think the 3 panels will survive the  reverse polarity ? 
 I’m probably 3 weeks away from being able t work on them 

Estragon

> @wellbuilt said:
> I reversed the mc 4 Connections at the panel after the breaker popped I changed the mc4 connectors but don’t seem to be getting out put from that string . 
>  The breaker stays on but no out put at the controler .
>   Don’t have a meter with me , and don’t. Know for sure how to read the meter for PV out put .

I'd start by setting the meter (which you probably need to find) to DCvolts and measure open circuit voltage by just holding the meter probes to the +/- contacts mc4 contacts for each suspect panel in reasonable light (doesn't have to be full sun, just light).

Vic

wellbuilt,. 

It is my assumption,   that the bypass diodes are probably toasted  --  shorted.   And that those diodes would need to be replaced,   if you can get the junction box on the PVs off,  without damage to the backsheet of the PV.   Often  a Polyurethane sealant/adhesive is used to stick the junction box onto the backsheet.   This is very tough stuff,   so a lot of care would needed in the process.

The breaker should be checked ...

All of the above is just guessing   ...   Thanks for that pic.       Vic

wellbuilt

I was afraid of that , my junction box is full of the   Polyurethane  adhesive I don’t now how to clean it out of the box .
 Maybe we have a bad  MC 4 Connection on the roof the boys where setting the panels . 
 I’ll have to go up and see . 

wellbuilt

Do you think all 3 panels will be bad or maybe just the last one where there was more heat ? 
 Wish I had some one else to blame  I hate silly  mistakes  especially when I make them 

mike95490

The weakest panel likely lost and died.  the other 2 may still be good, but have been stressed. 

Photowhit

I think it's hopeful that there isn't damage, Ryan(? at Midnite) @halfcrazy discussed backfeeding solar panels to melt snow, I thought it was discussed here, but it was a couple software versions back and I couldn't find a link on this forum. He discusses pushing 2X the rated output back through the panel here on an Outback discussion. 2x the rated output is about the most 3 would push back into 1 string.

FWIW - I don't think it's an option on the soon to be released Charge controller, I have a few Classics don't recall that option, I suspect if he stated this they had done some trial runs. It's about 3rd to last reply;

http://outbackpower.com/forum/viewtopic.php?f=15&t=3430

Raj174

@wellbuilt,
You stated that this happened early in the morning when the panels were producing 50 watts. This is a very small amount of power, less than 1 amp on that string. Certainly not enough to damage the breaker or the panels. IMO you may have a defective breaker, or possibly a bad connection in the string. As already stated, you will need a meter to troubleshoot this.

Rick

wellbuilt

Hi rick yes it happened at start up in the morning . 
 At first I thought it was a bad breaker , I wanted to try a reset but did not . 
 I started checking thing and realized my mistake . 
 Maybe one of the wires pulled out of the mc4  connectors ,the boys where having a hard time getting them out to move them around .   
 I hate Waiting weeks to be able to work on the stuff

littleharbor2

If you have the tool and MC-4 ends that would be a cheap and simple possible remedy if wires got tugged or if contacts got burnt or damaged.