Please look my design over.

[Brewman]

This is my first read draw up of what I'm wanting to build that will eventually go into a teardrop style camper. The load will be small, 12V fridge, 12V lighting, 1000W inverter (seldom used), 12V water pump (seldom used), USB ports (phone, tablet charging).

Parts List:
PV Two BP Solar 80W (on hand) Will upgrade as required.
SCC EPEVER Tracer 3210AN (Large enough for any load additions)
Battery To be determined.
Inverter Thinking 1000W Pure Sign Wave

As the pic shows, I have two meters shunted in. One is a battery meter for battery level. The second is wired off the fuse box for total load metering.

Please take a look and let me know if you see any problems in my connections and setup.

Dan

 

[Brewman]

I ended up ordering the 3210 tonight.

 

[MisterSandals]

Have you figured out how many watt hours the fridge will use in a day? And have you figured if this can be powered by 2 80 watt panels, produced in about 5 hours of charging in a day? (800wh)
And store 19 hours of power for same fridge in batteries of course.

 

[Brewman]

Battery size and PV will be upgraded as required.

 

[Brewman]

From the research I've done, a 40L 12V fridge pulls on average 40ah a day. If you have any different data I'd love to look over it.

 

[loverofpeace]

From the research I've done, a 40L 12V fridge pulls on average 40ah a day. If you have any different data I'd love to look over it.

If you buy a ARB/Domestic/other top brand fridge you can hit less than 40ah a day with it on 12V - ballpark would be 25ah for a 40L with those. Might be something to look into if you don't already have a fridge and the panels aren't pulling enough.

 

[svetz]

Can't really tell from the photo if the fuse box has it, but some disconnect switches to make life easier for maintenance might be useful. Is the inverter fused? Looks like a negative wire on the fuse box.

 

[Brewman]

Can't really tell from the photo if the fuse box has it, but some disconnect switches to make life easier for maintenance might be useful. Is the inverter fused? Looks like a negative wire on the fuse box.

The inverter fuse should go on the positive side of the battery right?

 

[Brewman]

If you buy a ARB/Domestic/other top brand fridge you can hit less than 40ah a day with it on 12V - ballpark would be 25ah for a 40L with those. Might be something to look into if you don't already have a fridge and the panels aren't pulling enough.

Haven't got the fridge yet, and thanks for the info.

 

[svetz]

The inverter fuse should go on the positive side of the battery right?

Short answer: Yes.

Although it probably depends on the vehicle's ground polarity, pretty sure I heard Will mention something about a positive ground at one point.... in practice (even for AC), the fuse goes on the "hot" wire closest to the source so that all the wires are all guaranteed to be safe. the problem with fusing after the load is that if the fuse blows, the load (appliance) could still be electrified and shorting to ground.

 

[Brewman]

Short answer: Yes.

Although it probably depends on the vehicle's ground polarity, pretty sure I heard Will mention something about a positive ground at one point.... in practice (even for AC), the fuse goes on the "hot" wire closest to the source so that all the wires are all guaranteed to be safe. the problem with fusing after the load is that if the fuse blows, the load (appliance) could still be electrified and shorting to ground.

Got it, thanks.

 

[Brewman]

So I did some changes to my test rig, I moved the fuse to the negative side of the battery and changed the positions of the shunts. What do you guys think?

The inverter pictured has two 20A fuses.

 

[svetz]

...The inverter pictured has two 20A fuses.

That's odd, really odd. It's labeled as a 350W inverter. So 350/12 = 29.1 amps on the DC side. Obviously 20A is too small for that.
But, at 700 peak on the AC side that's 700/120 = 5.8 Amps.

So 20 amps is too small for the DC and too big for the AC.

Are those fuses original, or did someone just replace them with something handy?

 

[John Frum]

That's odd, really odd. It's labeled as a 350W inverter. So 350/12 = 29.1 amps on the DC side. Obviously 20A is too small for that.
But, at 700 peak on the AC side that's 700/120 = 5.8 Amps.

So 20 amps is too small for the DC and too big for the AC.

Are those fuses original, or did someone just replace them with something handy?

Perhaps the fuses are in parallel.

 

[Brewman]

See...

 

[John Frum]

See...

350 / .9 / 12 * 1.25 = 40.509259259 fuse amps

 

[svetz]

Eureka!

There are two parallel DC circuits internally, each providing half of the available power ... each path fused separately... so two fuses. Thanks for the photo!

 

[Brewman]

350 / .9 / 12 * 1.25 = 40.509259259 fuse amps

Can you explain /.9/

 

[John Frum]

Can you explain /.9/

90 percent conversion efficiency.
I generally use .85 but its low wattage so I guessed .9.

 

[Brewman]

90 percent conversion efficiency.
I generally use .85 but its low wattage so I guessed .9.

Thanks