Switch/ fuse for solar panels

[Ricco1]

I should have thought about this before I fitted and wired my panels, but there you go. I'd like to incorporate either a fuse or (ideally) a switch between the panels and controller. This is so I can disconnect the panels before I service the batteries, without having to clamber on the roof and disconnect a fiddly connector.

 

I have 3 x 125 watt panels and a 30 amp MPPT controller. I can place the switch/ fuse just before the positive (6mm) wire enters the controller.

 

Any suggestions?

 

Thanks

[Jambo]

I was going to do this but then someone pointed out the clambering on the roof and disconnecting the fiddly connector approach so I didn't bother.

 

I've wiped out a couple of times clambering on my roof on cold mornings though so perhaps a switch would be more sensible

 

I haven't really had a need to disconnect the panels yet other than when I took them down for the St Jude storms. What sort of servicing do you do that requires disconnection?

[ditchcrawler]

You should have a fuse in the line anyway

[matty40s]

just another thing to go wrong.

 

undo the positive supply to the controller from whatever panels you 'ave, and go ahead and do your work.

You should have a fuse in the line anyway

The fuse should be between the controller and battery bank or shunt in most installations.

[peterboat]

just another thing to go wrong.

 

undo the positive supply to the controller from whatever panels you 'ave, and go ahead and do your work.

The fuse should be between the controller and battery bank or shunt in most installations.

I know you are right but on my Tracer it says disconnecting from the batteries without first disconnecting the panels will damage the controller! So in the event that the fuse blows the controller will be scrap as well

 

Peter

[Grace and Favour]

I know you are right but on my Tracer it says disconnecting from the batteries without first disconnecting the panels will damage the controller! So in the event that the fuse blows the controller will be scrap as well

 

Peter

I fitted an isolator switch between my controller and the panels, as well as an isolator (and then a fuse, of course) betwen the controller and the batteries.

 

It works well for me.

[Jambo]

I know you are right but on my Tracer it says disconnecting from the batteries without first disconnecting the panels will damage the controller! So in the event that the fuse blows the controller will be scrap as well

 

Peter

Yes my Outback says the same thing. I hadn't considered that possibility but it's an interesting point. My fuse is sized to be bigger than what the Outback can deliver so hopefully it'll hold together.

[SamKingfisher]

In practice it doesn't hurt my 30a tracer, I know because I have to reboot it from time to time on cloudy mornings or it gets stuck on a panel voltage under 20v. Usually that's 80-120v. Rebooting goes from say 2a to 8a.

 

 

Ps I'd like a switch, any recommendations for one I don't have to build a box for?

[smileypete]

A domestic install may typically use something like this:

 

http://www.ebay.co.uk/itm/Solar-Isolator-600v-25A-IMO-PRECISION-CONTROLS-32A-SI32-PEL64R-2-/390925703991?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5b04fcdb37

 

But for occasional use on a small boat install, a normal mains double pole isolator for a consumer unit, or MCB would probably do. There's ready made boxes that will take them OK:

 

http://www.toolstation.com/shop/Electrical/CED+Consumer+Units/Enclosure+IP20+2+Module/d190/sd2979/p30350

 

cheers, Pete.

~smpt~

[Chewbacka]

Thinking about it, you need a fuse as close as possible to the batteries as it is the batteries that will blow the cables in the event of a fault. As to a fuse between the panels and the controller, I can not see why as the fuse will be bigger than the max current the panels supply to prevent it blowing on a nice sunny day, in which case the panels will never give you a big enough current to blow the fuse as there is no more power available from the panels. Though pulling the fuse does give you an easy indoor method of disconnection if that is what you want.

[leeco]

I fitted one of these on mine but to serve 2 banks.

 

http://www.ebay.co.uk/itm/151236506016?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Maybe they do a on and off type.

[Ricco1]

A battery isolator switch seems that it would do the job, but something that looks a bit neater might be better, as I'll install it next to the controller.

[Ricco1]

Might this do the job? Wondering if it's easy to connect the 6mm wire to it though...

 

http://www.ebay.co.uk/itm/Red-Led-Toggle-Switch-12V-30A-HIGH-QUALITY-/111036599728?pt=UK_CarsParts_Vehicles_CommercialVehicleParts_SM&hash=item19da4c0db0

[leeco]

Might this do the job? Wondering if it's easy to connect the 6mm wire to it though...

 

http://www.ebay.co.uk/itm/Red-Led-Toggle-Switch-12V-30A-HIGH-QUALITY-/111036599728?pt=UK_CarsParts_Vehicles_CommercialVehicleParts_SM&hash=item19da4c0db0

Not sure you would get 6mm2 spade bits.

 

Maybe this might do .

 

http://www.ebay.co.uk/itm/BLUE-SEA-12V-BATTERY-SWITCH-MARINE-INBOARD-SWITCH-PANEL-BOAT-RV-/400451068894?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item5d3cbe63de

Maybe a yellow spade bit would take 6mm2 wire.