Panel wiring

[robstrom]

Simple question, well 2.
While installing panels, the sun will be on them, hence, power.
I have no battery yet.
As long as I don't plug them in to the charge controller, no damage correct?
2. Can I put a multimeter on the connectors to confirm continuity/ output, without a battery?
Be safe n do it out of the sun?
Thanks

 

[BigSur]

Simple question, well 2.
While installing panels, the sun will be on them, hence, power.
I have no battery yet.
As long as I don't plug them in to the charge controller, no damage correct?
2. Can I put a multimeter on the connectors to confirm continuity/ output, without a battery?
Be safe n do it out of the sun?
Thanks

Hello! I’m also new to solar and have been voraciously reading forums and watching videos. I feel I can answer this as I just did this with my first panel this morning

Yes, connecting your multimeter directly to the leads from the panel is appropriate. This measure is shown on your panel as Voc, or Voltage Open Circuit. This is considered “open” because it is not connected to anything. My 100w panel is rated at 22.6 Voc and in near direct sun it achieved 22.5V.

You are also correct about the solar charge controller, do not connect your panels to a SCC unless the batteries are already connected to the controller.

Hope this helps!

 

[Deleted member 23531]

Silicon panels are ok in the sun with no load; some thin film panels like cadmium telluride panels are not.

It is not really “safe” to make connections to live wires, including panels which are illuminated. You can put insulating tape over the ends of the wires and mount them during the day, but to be on the safe side I would plug them in at night. If you know what you’re doing, some of the connections are ok to make, such as series connections in an open circuited string (then you complete the current loop when it is dark). But for a first timer just plug them in at night.

 

[Deleted member 23531]

Just think of a string of panels as a DC arc welder! It basically is that when illuminated. If a surge of current flows in the connectors when they get connected, they will weld together and it would be dangerous.

 

[iamrich]

Just think of a string of panels as a DC arc welder! It basically is that when illuminated. If a surge of current flows in the connectors when they get connected, they will weld together and it would be dangerous.

Are you talking about connecting the panels to each other in series? You can short Positive to Negative on a panel without an issue. It will not exceed Short circuit current.

 

[Deleted member 23531]

Are you talking about connecting the panels to each other in series? You can short Positive to Negative on a panel without an issue. It will not exceed Short circuit current.

No, not talking about any particular connection, I’m just trying to instill a healthy amount of fear/carefulness in OP with that comment .

 

[iamrich]

If you are not getting shocked, your not trying hard enough.

 

[Deleted member 23531]

Lol, spend 10 minutes googling "arc flash" and it will make you be pretty careful. Just like watching slideshows of car accidents in driver training programs.

 

[iamrich]

Don't need to... I have done enough stupid things and survived to know better now. I have a bunch of probe tips, and line pliers with evidence of questionable decisions....

 

[Supervstech]

As long as you VERIFY with math first the voltage expected in the cables, and do not exceed the settings on your multimeter, it should be ok to test polarity, and voltage with sun lit panels. Remember, panels in series strings add voltage.
Panels in parallel add amperage. Use math to confirm limits first.
Mppt controllers take power and slowly test limits until Mpp is reached, then begin drawing current. As long as you are under the limits of the equipment you should be ok.
Always work with one wire at a time, never cross your arms connecting wiring, and don’t work wet or sweaty...
Sounds like night time is best for connecting wires.

 

[iamrich]

Sounds like night time is best for connecting wires.

I have watched a few videos of installers covering the panels with tarps. Not sure how effective that is, but it would definitely be less than full sun.

It is kind of ironic the if a bird craps on one cell of your panel it will cut the production in half it seems, but if you are connecting wires the panels somehow magically put out 200% rated power (Exaggeration obviously)

 

[robstrom]

Plastic backing of 1 panel was gouged during shipping, exposing the underside of the glass. I can tape/ heat gun it sealed if required.
Should I be concerned about panel integrity?
Thin glass with a lot of fine wiring running through it.
My guy will ship me a new one, if I make a case for damages.
Thoughts??

 

[Deleted member 23531]

Share a picture, please. You might try a sealant like silicone, not tape, to keep out moisture. But if possible you should file a claim with the shipper and get a replacement panel.

 

[Bud Martin]

If you are going to use RTV silicone on exposed copper, wires, make sure it is electronics grade, the regular (acidic) kind with vinegar smell should not be used.

ASI 388 - American Sealants Inc. ELECTRONIC GRADE RTV SILICONE

One part, moisture cure sealant cures to form a tough, durable, flexible rubber Ideal for bonding, sealing, encapsulating and protecting electronic parts. Works in temps from -70°F to 400°F.

www.americansealantsinc.com

i use Electronics grade in our electronics production line when needed.

 

[Boondock Saint]

After you wire them all together, just lick the plug and tell us if you think it tastes more like silicon or more like copper? Also please record it with your phone, we don't want any fakers up in here :D

 

[Deleted member 23531]

If you are going to use RTV silicone on exposed copper, wires, make sure it is electronics grade, the regular (acidic) kind with vinegar smell should not be used.

ASI 388 - American Sealants Inc. ELECTRONIC GRADE RTV SILICONE

One part, moisture cure sealant cures to form a tough, durable, flexible rubber Ideal for bonding, sealing, encapsulating and protecting electronic parts. Works in temps from -70°F to 400°F.

www.americansealantsinc.com

i use Electronics grade in our electronics production line when needed.

Good tip! I had no idea.