Unplugging your solar panel

[chris95040]

Hi folks,

I've got a 100 watt GoPower flex panel and pwm charge controller. Until I build the bimini that this will mount on, I'm leaving it in the cockpit and will disconnect and store when sailing.

Is there anything I should know about disconnecting a panel from the controller? Is it dangerous to do without covering with opaque material to block the light first? Should I wait a bit after doing that before disconnecting?

[svmariane]

Originally Posted by chris95040

Is there anything I should know about disconnecting a panel from the controller? Is it dangerous to do without covering with opaque material to block the light first? Should I wait a bit after doing that before disconnecting?

First: Relax.

Second: Disconnect the PLUS lead from the solar panel AT the panel.
Think of it as removing the plus lead from a battery. Okay? Okay.

Third: Disconnect the NEGATIVE lead from the solar panel AT the panel.

If needed:

Forth: Disconnect the PLUS lead from battery to solar controller AT the battery {or terminal block or whatever you have}.

Fifth: Disconnect the NEGATIVE lead from battery to solar controller any darn place you like.

Sixth: Grab a cold beer. Open. Chill, man.....

We have a circuit breaker installed twixt the solar panels {four in parallel} and the solar controller. Makes it easy when messin' 'round with stuff.

[svmariane]

Originally Posted by chris95040

Hi folks,

I've got a 100 watt GoPower flex panel and pwm charge controller. Until I build the bimini that this will mount on, I'm leaving it in the cockpit and will disconnect and store when sailing.

Is there anything I should know about disconnecting a panel from the controller? Is it dangerous to do without covering with opaque material to block the light first? Should I wait a bit after doing that before disconnecting?

Sorry... Forgot to add:

No, it's not dangerous if you FIRST disconnect the PLUS lead AT the solar panel. Some (probably many) solar controller's manuals warn you to disconnect the panels FIRST, and THEN the battery. What I said up above.

You know... In fifteen years of using solar panels I've NEVER seen nor heard of somebody actually covering the panels with opaque material. Hmmmm...

As for waiting - The panel is like a battery (kind of) in that it provides power/amps/volts da yada da yada. There is no capacitor involved that needs discharging. So chill out, k?

And welcome to the world of SOLAR POWER !!!! We run our entire boat with solar and wind - no genset, no shore power; only run the main diesel a half hour per month to keep her happy.

James

[Ex-Calif]

Originally Posted by svmariane

First: Relax.

Second: Disconnect the PLUS lead from the solar panel AT the panel.
Think of it as removing the plus lead from a battery. Okay? Okay.

Third: Disconnect the NEGATIVE lead from the solar panel AT the panel.

If needed:

Forth: Disconnect the PLUS lead from battery to solar controller AT the battery {or terminal block or whatever you have}.

Fifth: Disconnect the NEGATIVE lead from battery to solar controller any darn place you like.

Sixth: Grab a cold beer. Open. Chill, man.....

We have a circuit breaker installed twixt the solar panels {four in parallel} and the solar controller. Makes it easy when messin' 'round with stuff.

Wait, what?

Unless there is reverse current protection the + wire from the panel is wired directly into the boat DC bus. Once removed from panel any contact with a ground path and you have sparks. remove any ground path first.

1 - remove ground at boat dc bus - boat supply cannot get back to battery
2 - remove ground at panel - panel supply cannot get back to panel
3 - remove + from boat battery - bigger potential than panel
4 - remove + from panel

Better yet get a plug - male end on panel side.

Please correct me if I am missing something.

[Sailmonkey]

Originally Posted by Ex-Calif

Wait, what?

Please correct me if I am missing something.

It's usually a very bad idea to disconnect the controller from the battery when the panel is still connected to the controller.

Just unplug the damn thing, if it makes you fell better, throw a towel on the panel while unplugging it.

[Ex-Calif]

Originally Posted by Sailmonkey

It's usually a very bad idea to disconnect the controller from the battery when the panel is still connected to the controller.

Just unplug the damn thing, if it makes you fell better, throw a towel on the panel while unplugging it.

Please disregard - I completely glossed over the part about having a PWM controller.

Please resume your normally schedule program...

[chris95040]

Thanks!

I guess I'm more worried about inductance than capacitance- but having no idea how these things work I can't tell if thats a concern or not. Based on your experience, sounds like its not.

(By inductance i mean if current is suddenly interrupted by unplugging, will voltage on the panel output suddenly spike to an unsafe level, v= L*di/dt)

[goboatingnow]

Originally Posted by chris95040

Thanks!



I guess I'm more worried about inductance than capacitance- but having no idea how these things work I can't tell if thats a concern or not. Based on your experience, sounds like its not.



(By inductance i mean if current is suddenly interrupted by unplugging, will voltage on the panel output suddenly spike to an unsafe level, v= L*di/dt)

No. Firstly it's a current not a voltage source and secondly the inductance is tiny. On disconnection the panel voltage will rise to Voc and that's it.

Dave


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