Remove and replace PV roof panel


New Member
Apr 14, 2021
I have a 16 panel, 4.5kw, grid tie, roof mounted PV system that I had installed about 6 years ago.
Then, had a new roof installed about 2 years ago.
The contractor brought in "electricians" to remove and replace the PV roof mount.
Watching the "electricians" at work gave me very little confidence in their PV abilities.
One panel/microinverter is now off line, and has been for 6 months or so.

I have begun to work on checking out the PV panel/microinverter that isn't reporting to the installation's software.
To get to the offending panel, I need to remove a second panel to get access to the one that isn't reporting.

So far all I've done is remove the clamps from the 1st panel.
The first thing I notice on turning it over, is that the cables are labeled "Do Not Disconnect Under Load".
Will disconnecting the installation from the grid and/or covering the panel with cardboard make it OK to disconnect it?

If not, what do I need to do to disconnect and remove this panel so I can get to the one I need to disconnect and fix?

16 - Solarworld 280 W panels
16 - Enphase M250 microinverters
Last edited:

Frank in Thailand

making mistakes so you don't have to...
Feb 17, 2020
Normally ,yes.
That's all the action you need to take to be able to disconnect.

Cardboard is a good extra safety.
Even better would be at the end of the day with lower light.

The AC current produced by the other panels is lower that time.

It shouldn't be more hasle then disconnect a power plug from your socket.
Equally dangerous.
Disconnect a 3000 heater by pulling the plug is asking for sparks.
Turning it off and pull out...
Not a problem.

Obviously the wires to the microinverter are connected differently as it need to be waterproof.

Sorry to hear about your problems!


New Member
Apr 14, 2021
Thanks fhorst,

I has disconnected the system several times before when requested by those up on the roof doing the work.
I didn't want to make any assumptions when I was the one up there doing the

All of my working will be done during the day time.
I will not go up on the metal roof while it's raining, wind is high, or lighting is poor.
I do use a harness and rope to secure myself.
I'm more afraid of falling than getting zapped.

The sun is out and I will soon begin taking it apart again to find the problem.
When I get the panels off, I can switch them.
If the bad panel changes location, then the panel is the problem.
If it doesn't change, then the M250 or something else will be the problem.
I'll need to take a VOM up with me.


New Member
Apr 14, 2021
I am moving rather slow on this, but am checking things out so that it will go as smoothly as possible when I actually begin.
I've unclamped, flipped over, then replaced the interfering panel a couple of times to see exactly what needs to be done to locate and work on the non reporting microinverter (MI).
The pane's cables connect directly to the MI's cables.
If the connections are the problem, I may have to cut off and reswage new connectors on.

Instead of hamfisting the cables apart, I've ordered an MC4 disconnect tool.
Should be here in less than a week.
Got the rest of my tool needs pretty much worked out.
Then, I can begin disassembly and locating the source of the problem.

Our array was installed by a contractor that I believe is no longer in business.
They split up with one doing only offgrid installations.
The other began a different telephone tower business.
That was probably destroyed by the eruption.

Then, we had another contractor install a new roof who setup to have the PV install removed and replaced.
I'm assuming that warranty work for the original install is a lost cause.
Plus, I want to do the maintenance myself from here on out.

So questions:
If the problem ends up being a corrosion problem with the connections:
Can a dielectric grease be used on the panel/MI connections to stop and offset any possible corrosion?

If the problem is the MI, will I be able to use the 25 year warranty to replace it myself?
Might have to send the old one in for diagnosis and repair first, might just buy an extra MI to have one around.


Photon Sorcerer
Mar 22, 2021
I use Ideal Industries No-Alox on solar connectors, just a dab on the female connector and this will seal out water and prevent any oxidation, this compound is formulated for Aluminum/Copper joining but i find it prevents oxidation everywhere i use it. It prevents set screws on aluminum electrical connectors from freezing in place, I have even used it on Flooded Lead Acid Battery Terminals and it protects even that....Found in electrical at Home Cheepo