Fold out solar panel

Photobug

Well-known member
I guess I could throw a 7.5A fuse in it, but that's still likely achieving nothing.

The fuse at my batteries between the controller and them I have a 10A even though the controller max operating is 15A, reason being that I'll never see more than 10A and I don't feel like pulling it and installing a 15A fuse becasue I'll have to go back through setup, unless the Victron app saves the inputs?

Unless you are protecting sensitive electronics: (I am thinking comm radios, stereos, maybe gps and fridge) a fuse is put in place to protect the wiring. If the unit itself is so sensitive it might have its own inline fuse.

A question for those in the know. I am currently wiring a new panel in my home. A 10 gauge wire is good for a 30 amp circuit. For 12V a 10 gauge wire is good for 45amp circuit. Why?
 

dreadlocks

Well-known member
uh, 45A @ 12VDC on 10AWG is only good for like 3ft.. the 120VAC 30A Circuit in yer house is presumably much longer than 3ft... The higher voltage, and Alternating Current.. allow you to run more power, over greater distances, with less copper.. if your house used DC like Thomas Edison wanted, the'd be far more copper in the walls of your house than your house would even be worth.. to get 45A of 12VDC 100ft you'd need thicker cable than 0000AWG
 

Photobug

Well-known member
uh, 45A @ 12VDC on 10AWG is only good for like 3ft.. the 120VAC 30A Circuit in yer house is presumably much longer than 3ft... The higher voltage, and Alternating Current.. allow you to run more power, over greater distances, with less copper.. if your house used DC like Thomas Edison wanted, the'd be far more copper in the walls of your house than your house would even be worth.. to get 45A of 12VDC 100ft you'd need thicker cable than 0000AWG

If I ran every dc powered object I own, I would be hard pressed to reach 20 amps. Still would like to wire for potential future upgrades. Since the Anderson Powerpole calls its 10gauge connectors "45 amp" I was planning on putting a 45amp fuse inline to protect this wire. While I don't expect to draw 45 amps, should I downgrade the fuse to 30 amps?
 

dreadlocks

Well-known member
Fuses are determined by wiring, they are intended to pop before wires go all melty and start a fire.. you want it higher than your loads to avoid nuisance trips, but low enough they trip before damaging any of your electrical wiring.

This site is a great help for figuring out what size wire and fuse is appropriate for a given load: http://circuitwizard.bluesea.com/
 

01tundra

Explorer
I changed out the 10A fuse at the battery serving the MPPT with a 15A, and it kept all my setting....which is great news considering that I'm installing ferrules on all the wire ends at the controller tonight. When Victron states that their terminals will accept 10AWG.......they must mean a really, really skinny 10 ga missing about half the strands :rolleyes:.

I'm still on the fence on whether to remove the fuse at the panel, if it's basically doing nothing then it just becomes a source for potential voltage drop in the future from being out in the elements, sometimes less is more. Just thinking that if I removed it and soldered the 10 ga. positive lead directly to the panel I've removed four crimped connections, two spade connectors in the fuse housing and eliminated a fuse holder dangling out there.
 

dreadlocks

Well-known member
yeah I crossed a few wires there, muh bad, ive taken a beating today troubleshooting electronics.. guess a better way to look at it is, 45A @ 12v is merely 540W of load, whereas 30A @ 120v is 3600W of load.. so even tho his house circuit breaker is smaller than an automotive circuit breaker, its handling much more power over similar gauge wiring.. AND because its AC, you can push more of those watts further than you ever could w/DC using similar gauge wiring.

Low Voltage DC vs High Voltage AC is Apples vs Oranges..
 

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