Tomorrow we plan to remove four older solar panels in anticipation of driving to FL from MD in a few weeks to have a whole new set-up installed. The panels are wired in series so there is only a single wire leading to into to roof. Am I okay to simply hack off the leads wrap them up well with electrical tape and secure them well with zip ties temporarily for a few weeks... or could this cause issues when I hook the battery back up?
Thanks
James
James,
Every solar installation I have seen or heard about has some kind of a positive disconnect switch in the wiring between the panels and the controllers. This is a safety thing, since there is really no way to turn the panels "OFF". Having a switch allows you to work safely on any of the equipment "downstream" of the panels.
If you have such a switch, simply disconnect the panel wiring at that point. Then there will no worries about hooking the battery up, regardless of what you choose to do with the wiring on the roof.
From what you mentioned, if old solar panels were wired in series or parallel, they would likely only have a pair of wired leading into the roof. So why not consider that the existing cable may be reused, so why cut it off. Find a way to roll it up, and secure it to something on the roof, etc.? You could tape up the roof ends to keep them safe, disconnect batteries from controller with its switch, disconnect roof cable at other end?
What's the problem with the older panels?
Agree with Barry. The wire going down may be of sufficient size to be used from a combiner box to the controller. Leave it until you are sure that you can't use it because running wire can be a real pain and run up your installation costs.
Four panels, six years old. Significant discoloration underneath the glass of two of the panels. Wiring is too thin. In full midday sun at 65 degrees, we were drawing 6-8 amps on a 60-70% full battery, and there are 480 Watts on the roof. That isn't good. Bad install design that restricts further panel additions, and I had to remove 2 rooftop accessories that were severely blocking the panels simply to get shade-free sun to all four simultaneously. Existing panels happen to be inconveniently sized for maximizing roof space (the old One Pillow isn't enough, but Two Pillows is too much issue), and I feel replacing is a better option that investigating panel functionality in this case.
I am by no means knowledgeable on the topic, but whoever installed our system didn't follow any of the most important basic rules that I've read about time and time again - I've seen enough to feel strongly that if an upgrade is in order, it will better to start from scratch.
Thanks to all for advice - I will follow it!
James- Solar happens to be my profession. My advice, like others here, I would retain as much wire as you can on the roof that comes from a combiner box on the roof, or passes thru the roof. It may be reusable. At worse it is USE-2 wire, may even be PV wire which has thicker insulation. If it cant be utilized with the new panels, configuration, etc. the installers will know and will handle.
As for disconnecting PV, NEVER unplug of cut the DC wires from PV panels in daylight and "UNDER LOAD". You will draw a blue ARC up on the roof which is very dangerous. So, shut off any switches you can find to the equipment, that should remove the load and should open the circuit. Early morning or later at dusk with minimal light is safest. Or, simply let the installer do those tasks. Remember, Solar PV is an "always on" generator producing electrons anytime photons (sun light) hits its surface. Can be dangerous. The PV wire's ends can be protected with electrical tape and secured with zip ties in a loop.
Good luck! Jeff
Thanks Jeff - I ended up doing this on Tuesday night when I come home from work. Got a nice spotlight torch, a headlamp, and unhooked the battery (easier - because the solar disconnect switch was behind a panel with 8 screws), and did it in the pitch black of night. That had it's own dangers, surely not ideal but all ended well!
Otherwise, your suggested methodology is pretty much exactly what I ended up doing. Glad to know I was on the right track.
James