Solar panel installation rewire

[Familymarmite]

I plan to tidy up the dealer installed wiring on my solar panel installation and at the same time replace the charge controller.
My question is. "Is it ok to have the solar panels disconnected from the charge controller while I carry out the work, with the panel exposed to sunlight without causing any damage"?
any advice on the correct procedure for disconnection and reconnection greatly appreciated.
Is it also good practice to install a fuse/switch between the panel and the controller?

 

[Googlebot]

No, cover the panel with carpet or cardboard so there will be no output whilst you are working.

I have never installed a fuse or switch between panel and controller.
Hope that helps.

John

 

[autorouter]

Is it also good practice to install a fuse/switch between the panel and the controller?

Some controllers are fussy about the sequence of connecting up. They need the battery connected first, then the panels, because they automatically recognise a 12V or 24V setup. So whenever you disconnect the batteries you need to disconnect the panels.

A switch is all that is needed, but some people are happier with a fuse that can be pulled out easily. In fact a fuse is often cheaper and easier to wire than a switch. There's no way a solar panel can blow a fuse that can take the normal output of a panel, so a fuse isn't actually needed.

 

[pappajohn]

For the life of me I can't see the reasoning behind covering the panel other than to prevent accidental short circuit of the panels Pos and Neg wires.
If nothing is consuming power then no power is produced.....it just has the potential to be produced.
If an electrician is working on a building he will turn off the supply before disconnecting wiring, he won't get the electric company to turn off their Generator.

 

[mitzimad]

you will have voltage on the panel wires if its in sunlight do one at a time and tape them to be safe its alway battery first way to remember is BB Battery Before Ive never fused between battery and panel but it will make disconnecting easier in future

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[HandyAndy]

Other than taping up the cable ends to ensure they don't touch anything they shouldn't, then it's not worth a second thought.
Covering the solar panels, while strictly safer, is no where near necessary unless you have a large bank of them creating quite a lot of juice.
and no you won't damage anything by "short circuiting" them either. (twisting the wires together)
Disconnecting the charge controller while the solar is still connected to it however "MAY" be a bad move, so do make sure you disconnect solar from the controller before you disconnect the controller from the battery..

 

[Googlebot]

For the life of me I can't see the reasoning behind covering the panel other than to prevent accidental short circuit of the panels Pos and Neg wires.
If nothing is consuming power then no power is produced.....it just has the potential to be produced.
If an electrician is working on a building he will turn off the supply before disconnecting wiring, he won't get the electric company to turn off their Generator.

By covering the panel you turn off the power the same way as if you had used a switch. The alternative is a possible short circuit of the panel.

 

[tonyidle]

By covering the panel you turn off the power the same way as if you had used a switch. The alternative is a possible short circuit of the panel.

Which will do it no harm whatsoever.

 

[Googlebot]

Which will do it no harm whatsoever.

Really? You learn something new every day.

 

[tonyidle]

Really? You learn something new every day.

It isn't like a lead acid battery which has a very low internal resistance. One tested spec of a panel is the short-circuit current. Leaving a panel short-circuit when it's producing a good output would eventually cause it to warm up but you'd be bored waiting for it to get hot enough to hurt itself.

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[TinaLes]

Be very, very cautious, when mucking around with solar panels & 12 volt lead acid batteries, the correct sequence of disconnection is as detailed below.
Les

 

[Paul an Jane MK]

The supplier advised me to connect loads e.g leisure and engine battery before solar panel and as a solar panel generates a good amount of current to ensure it was covered so no electricity being generated when I connected to panel.

Having spent more than enough time up a ladder and on the roof fitting the panel I did all the wiring and installation and then left the final connection of the the two solar wires in to the control panel until nighttime.

I popped out about 10pm and within a few mins job done.

 

[jezport]

to be safe its alway battery first way to remember is BB Battery Before Ive never fused between battery and panel but it will make disconnecting easier in future

Not its not when dealing with a solar panel and controller.
You risk damaging the controller!
Disconnect panel first!

 

[autorouter]

Solar panels on a house roof are often connected in series, and it's normal to have half a dozen or more 36V panels in series in what is called a 'string'. The voltage on this string is at least 6 x 36V, which is potentially lethal, especially to someone on a roof or a ladder.

Motorhome panels are usually in parallel, so voltages are 36V or lower. These voltages are not dangerous. As others have said, the short-circuit power is also not a problem.

 

[Minxy]

You should disconnect the the solar panels from the controller before you do anything else, that is what some of the controller manufacturers recommend, this is to prevent the current from the panel going into the controller with nowhere to go which could damage it.

This is one reason of the reasons I fitted fuses in the cables between each of the solar panels (connected in parallel) and the controller in my previous camper, it made a quick and easy way to stop the charge if I needed to and also gave me a way to check the output of each panel using a multi-meter in the fuse holder slots.

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[Familymarmite]

Thanks for all your replies.

 

[Off da Grid]

Volts thrill amps kill.
The reason it’s recommended to cover the panels before dis/connecting is you can get a spark that could ignite any flammable gases that could be present.
If it’s easier wait till dark and tape or put a chock block on the wires from the panel to avoid problems.
I didn’t bother with fuses or switches between the panel and the controller.