Solar shed lighting setup - correct approach?

Thread Starter

Upex

Joined Nov 10, 2013
76
Thanks nsaspook. I'll definitely plumb in a ground, as will be using twin and earth cable, and the light cases are wired for earthing, so makes sense.

Now that you mention it though, I assume that any old conductive metal rod stuck in the dirt will do. I thought I'd earth it up, but hadn't though how.

Anything I need to consider/think about? The conductor, how/where its put in the ground, how deep etc?

Also, a stupid question, but I am right in thinking the lamps need to be in parallel, not in series?

Thanks,

Upex
 
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nsaspook

Joined Aug 27, 2009
8,905
I used a standard big box store 6 foot rod. I salt the fence line to kill weeds so I drove it in at an angle near it as this was a additional rod not the primary and there are car sized rocks just under a soil leveling cap the house was built on.




Yes, all the lamps are parallel to the voltage source.
 

Thread Starter

Upex

Joined Nov 10, 2013
76
Wow nsaspook, that's a massive rod you got there! But not sure on the mellons!

Does it need to be that big? The mothers house is very old and built on land that is full of massive chunks of very old stone and granite, I think ill have real trouble in trying to get something that deep.

Not sure what you mean by big box store though?

Thanks, Upex
 

nsaspook

Joined Aug 27, 2009
8,905
Wow nsaspook, that's a massive rod you got there! But not sure on the mellons!

Does it need to be that big? The mothers house is very old and built on land that is full of massive chunks of very old stone and granite, I think ill have real trouble in trying to get something that deep.

Not sure what you mean by big box store though?

Thanks, Upex
https://en.wikipedia.org/wiki/Big-box_store

What matters is conductivity. A long buried plate in a trench with a solid electrical connection will work in poor soils. Placing something conductive under and on top off like coal or coke powder and waste iron filings mixed with a Portland cement 50% binder to make a conductive slurry mixture before covering with dirt helps.
 

Thread Starter

Upex

Joined Nov 10, 2013
76
Ok, thanks nsaspook. Will have a look into a rod vs plate etc and see what I can come up. Wish we had your big box stores!

Just need to sort out the switching now and should be good to go.

Been looking at some remote controller switch thingies, so my mum could turn on the lights before getting to the shed, as seems a tad pointless for her to have to get there in the dark, to turn the light on etc, as given the voltage drops already discussed, there is going to be no point in trying to extend out for a switch closer to the house, as it would need massive cable.

Would something like this work in place of the switch in my previous bad diagram?

http://pages.ebay.com/link/?nav=item.view&id=121454938779&alt=web

Think it would be ok, as says max load of 10a, and with my 8 lights, I think I have a total load draw of 6 2/3 amps, so a decent bit of headroom there.

I like the 4 channels, as would match up to the 4 sets of 2 lights, but guess a 2 channel would be better (3 internal and the 1 external on one, and the external 4 across front on second), but wonder if you can forsee any issues with this type of switch vs my set up?

Thanks, Upex

Edit:
just spoke to mum and she's asked if we can have a set up that involves a light sensor to turn on automatically. (She has chickens so would like the lights to kick on at dark and then be turned off by mum at night).

I guess were after:

Light sensor turns on lights at dusk (at activation sensor level of course).
mum turns them off when chickens are in bed (via switch - hopefully remote).
mum then turns lights on in morning via remote (if dark of course).
light sensor turns off lights at dawn (at trigger level) if mum switched them on of course.

Thought about a timer, but that'd need constant adjustment to on and off times, so isn't practical. Thought about the light sensor alone, but it'd stay on all night, which we don't want.

Is the above combo of manual on/off and an auto light level sensor possible? As neither option on its own is what were ideally looking for.

If the above combo is possible, any tips, ideas or guidance on how I can achieve it please?

Thanks, Upex
 
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nsaspook

Joined Aug 27, 2009
8,905
Sounds like feature creep is setting in. :eek: Setup the main switch with a provision for remotely powered latched relay(s) via a small control cable from the house.
 

Thread Starter

Upex

Joined Nov 10, 2013
76
Yeah, but if I can do this, that's it then, told her no more and that's actually the ultimate solution she's looking for, if doable at all, if not, the previous remote switch will be 90% and will help loads, so I guess this light sensor function is a nice to have.

I'll read up on what you said, we don't understand it at present, but the cable bit thinks a no go, as the house is a long way from the shed, say 200m in a straight line, but I'd need to move it out the way so likely far more than that.

Thanks, Upex

Edit:

If i put a photocell after the switch on each output (ie each set of 2 lights - so 4 photocells in all) then would that work?

Thinking of the above set up, I think it would pretty much meet the needs and avoid the lights being on when not needed etc:

when switch is off, no lights regardless if day or night.

when switch is on, during day, then lights not on as the switch would give power, but the photocell would not allow current as its daytime.

when switch is on and its night, the photocells allow the lights to come on.
 
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nsaspook

Joined Aug 27, 2009
8,905
All those photocells and timers use energy from the battery so if I HAD to have it I would use only one for the master on/off switch. One last thing about wiring, use a quality Fuse and holder. I tried to go cheap once with a main 40A fuse for car audio with solar and it looked like this after about a year of heat/cooling cycles loosened up the wire contact screws.

bad_fuse.jpg
 

Thread Starter

Upex

Joined Nov 10, 2013
76
Kor blimey, that was (hopefully) a lucky escape.

Any steer as to what type, make etc fuse I should use? As very keen to avoid that scenario!

Not sure how I'd use one photocell, as the remote switch has the 4 output channels. And I think that adding it before the switch would default the switch to off (when photocopy cuts power in the day) so they then wouldn't come on at dusk without being turned on after the photocell has switched on already.

I think I'll try adding the photocells after switch, just to 2 of the outputs, 2 lights inside and 2 outside. That way is only half the drain (vs 4 photocells) but does the auto on that I'm after. If its drains too much, hopefully the biggest batteries and another panel will negate the loss (if we need to expand it that is).

Many thanks for all your help nsaspook, its much appreciated and I'm thankful for you sticking with me, realise I've prattled on and asked lots of questions.

Many thanks, Upex
 

nsaspook

Joined Aug 27, 2009
8,905
Kor blimey, that was (hopefully) a lucky escape.

Any steer as to what type, make etc fuse I should use? As very keen to avoid that scenario!
I was pushing 40+ amps into the connector with just a single set screw to compress stranded cable. Not a good setup.

I'm now using marine quality fusing systems.

Regular AGC/MDL type holders/fuses or blade types should be ok at your power levels.
https://www.bluesea.com/products/5024/ST_Blade_Battery_Terminal_Mount_Fuse_Block_Kit
https://www.bluesea.com/products/5018/ST_Glass_6_Circuit_Fuse_Block_with_Cover
 
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nsaspook

Joined Aug 27, 2009
8,905
Today I'm testing all the connections with a max load (101F and AC at full blast) with full solar power. The battery bank is taking up the slack.

PIC32 network interface controller

PIC18 solar controller

Looking good so far 0.18 volts loss from the battery terminal to the inverter @ 710W with 2/0 charger cables and a 3/0 battery cables.

 
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Thread Starter

Upex

Joined Nov 10, 2013
76
That's a neck of a set up nsaspook, looks good.

My instal on hold, some shed and stuff being moved, so will have to hold off till its all done. Been waiting months and want it done done, but better than having to take it all out and reinstall again lol.
 
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