OUCH, panels still hurt on a cloudy day

[Quattrohead]

I have been swapping panels around, taking the 330w 60v Panasonic panels over to the new home to install and replacing with 315w 40v Hyundai until we move out of here.
Anyway, I flipped the breaker off for that string and went about my work. I noticed one of the paralleling Y was water damaged but as I am not paralleling the Hyundai I removed it and poked the 2 wires out the front to remind me to replace the MC4's later.
Loaded up the trailer and flipped the breaker back on. Looked at the EG4 and saw no input on a PV string.....ahh that's right I needed to replace the MC4.
Cracked out the tools, sat on the ground in front of the panels, cut off the old connector and stripped back the wire, put the metal pin into the ratchet crimper and gave it a squeeze. All good. Gave it another squeeze but this time hit the little metal latch release........BUZZZZZZZZ went my !ucking brain. I swear that is what I heard.

So remember folks, even on a cloudy day, your panels are still producing hundreds of nasty DC volts even if only a few hundred watts.
My thumb still tingles.

 

[Skypower]

Glad you’re still with us!

 

[Adam De Lay]

Ouch!

 

[Hedges]

Yup, near full voltage with very little light, cloudy or pointed away from the sun.
Even an "opaque" cover probably doesn't drop voltage below what will shock you, or current below what can cause harm.

Those techniques are sufficient to prevent arcing.

Only saving grace is that DC requires significantly more current to stop your heart than does AC.

Current has to flow in a loop. An undamaged PV panel with both wires unplugged, you should be able to contact one or the other wire without getting a shock. If the panel is damaged or otherwise has high leakage, then frame on mounts or the ground could complete the circuit through you.

Do you know how the circuit was completed? Was other cable plugged in?

 

[Quattrohead]

Do you know how the circuit was completed? Was other cable plugged in?

That is the mystery to me, I was only in contact with the ground and 1 wire.

 

[Supervstech]

That is the mystery to me, I was only in contact with the ground and 1 wire.

Sounds like a bad panel to me. Or was the other wire tied to the array, and you were getting juice from the circuit throuh the controller?

 

[Hedges]

And the panel was only in contact with ground (by its frame) and you (by one wire)?
The panel's other wire was unconnected?

Measure voltage from each wire to frame. There may be leakage.
There is capacitance, not sure if enough to carry (step-function transient) current sufficient for you to feel.
If glass is wet, capacitance could be greater.

 

[HOU_Castle]

I have been swapping panels around, taking the 330w 60v Panasonic panels over to the new home to install and replacing with 315w 40v Hyundai until we move out of here.
Anyway, I flipped the breaker off for that string and went about my work. I noticed one of the paralleling Y was water damaged but as I am not paralleling the Hyundai I removed it and poked the 2 wires out the front to remind me to replace the MC4's later.
Loaded up the trailer and flipped the breaker back on. Looked at the EG4 and saw no input on a PV string.....ahh that's right I needed to replace the MC4.
Cracked out the tools, sat on the ground in front of the panels, cut off the old connector and stripped back the wire, put the metal pin into the ratchet crimper and gave it a squeeze. All good. Gave it another squeeze but this time hit the little metal latch release........BUZZZZZZZZ went my !ucking brain. I swear that is what I heard.

So remember folks, even on a cloudy day, your panels are still producing hundreds of nasty DC volts even if only a few hundred watts.
My thumb still tingles.

At the very least, cover the panel with blanket if you plan to do simple and quick fix. Else, have the panel face to ground.

 

[SparkyJJO]

At the very least, cover the panel with blanket if you plan to do simple and quick fix. Else, have the panel face to ground.

But what if it is bifacial?

 

[Brett V]

Even on a cloudy day, most of your voltage potential is there.

 

[Danke]

But what if it is bifacial?

Spray paint the backside.

 

[JS43]

At the very least, cover the panel with blanket if you plan to do simple and quick fix. Else, have the panel face to ground.

I have gotten voltage across the connectors even with the panels in complete shade and facing the trailer with the backside alone facing out. Even then they can suck in enough heat to give a charge off. So laying them face down may not help. These are not bifacial panels either

 

[Quattrohead]

But what if it is bifacial?

Spray paint the backside.

A valid concern indeed ?

 

[Quattrohead]

And the panel was only in contact with ground (by its frame) and you (by one wire)?
The panel's other wire was unconnected?

Measure voltage from each wire to frame. There may be leakage.
There is capacitance, not sure if enough to carry (step-function transient) current sufficient for you to feel.
If glass is wet, capacitance could be greater.

Ground was damp, panels lifted off the ground with 2x6.
I think it was the cable from the inverter that got me. Yes I had switched the CB back on and forgot. So that voltage could have come from the inverter.
Anyway I am fine, this is just to warn everyone that panes can hurt you no matter what the weather and even good technical people can get complacent and hurt.

 

[Tulex]

I can relate. In fact, if I remember correctly, it was just today. It was a cloudy day with light rain, near sunset. Connecting the panel wires to the terminal block that the underground wires would connect to. Thought I had the one panel wire far enough away, but when stripping the other wire, I brushed my hand against it's mate. OW is exactly what came out of my mouth. Finished and connected inside, and checked Solar Assistant. Said 280V and only 40w, but all I know is that it hurt.

 

[Nobodybusiness]

I have been swapping panels around, taking the 330w 60v Panasonic panels over to the new home to install and replacing with 315w 40v Hyundai until we move out of here.
Anyway, I flipped the breaker off for that string and went about my work. I noticed one of the paralleling Y was water damaged but as I am not paralleling the Hyundai I removed it and poked the 2 wires out the front to remind me to replace the MC4's later.
Loaded up the trailer and flipped the breaker back on. Looked at the EG4 and saw no input on a PV string.....ahh that's right I needed to replace the MC4.
Cracked out the tools, sat on the ground in front of the panels, cut off the old connector and stripped back the wire, put the metal pin into the ratchet crimper and gave it a squeeze. All good. Gave it another squeeze but this time hit the little metal latch release........BUZZZZZZZZ went my !ucking brain. I swear that is what I heard.

So remember folks, even on a cloudy day, your panels are still producing hundreds of nasty DC volts even if only a few hundred watts.
My thumb still tingles.

I feel your pain.

Did a very similar thing yesterday.
Moving all my panels from Sinclair to Powerfield racks.

Got all the panels moved and was hooking them up.

All cloudy. Misting rain even.

Went to hook up string to combiner and zap! 260vdc.
Not much current mind you but damn if it won’t wake you up!

Needless to say I need to disconnect at least one end of the string before touching.
Should have known that but fog of assembly I guess trying to hook it all up.

Live and learn.

 

[Quattrohead]

My thumb still hurts a few days later, I think it burned a little.
I told my girlfriend about it, she gave me the look.
Probably rightly so, I shouldn't be getting quite severe electric shocks in my mid 50s ?

 

[wildbillpdx]

I shouldn't be getting quite severe electric shocks in my mid 50s ?

What about someone like me who's 68?

 

[registered-bum]

What about someone like me who's 68?

Doggone Bill - is half the crew here boomers er something (asking for a friend)?

 

[Nobodybusiness]

Doggone Bill - is half the crew here boomers er something (asking for a friend)?

Yup.