Hot to touch fuse (solar) UPDATE

[Dirtpig]

I've installed my solar charging system myself. I have it fused both from panels to controller and also from controller to batteries. Wire gauge used was 8awg. I've just recently noticed both fuses get very warm when charging say 10-16 amps. Fuses I have installed are 35 amp fuses. I have ordered car audio fuse holders and hoping maybe that will fix the heat issue. Wires themselves are not even warm. Anyone have this problem?

[Chris_Bryant]

I've used a regular Square D box with type QO breakers- rated for DC up to 48 volts. Makes a handy disconnect, as well.

[CJW8]

Yep, that is the exact fuse and holder I used. As others have said, not really needed neat the controller but I already had them and wanted an easy isolation point there.

[hedge]

I feel your pain trying to find stuff in Canada for a decent price.

I've bought blue sea stuff from the site below, the prices are pretty good and free shipping if you spend more than $100.

http://ca.binnacle.com/index.html

[Dirtpig]

Well i installed the car amplifier grade maxi fuse blocks today. It definitely made the heat issue go away so i am blaming the problem of hot fuse/fuse holder on the insufficient contact area for the amp load going through the small fuse and cheap fuse holder i initially used. I will attach some photo's. The idea of a circuit breaker is a good one and also one that i thought of but to buy non-hongkong breakers is pretty big money. I am still able to easily yank the fuses out if i want to disable solar charging for some reason, they are quite big and easy to grab onto. Thanks for everyones input.

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[scrubjaysnest]

Dirtpig wrote:
I've installed my solar charging system myself. I have it fused both from panels to controller and also from controller to batteries. Wire gauge used was 8awg. I've just recently noticed both fuses get very warm when charging say 10-16 amps. Fuses I have installed are 35 amp fuses. I have ordered car audio fuse holders and hoping maybe that will fix the heat issue. Wires themselves are not even warm. Anyone have this problem?

Very reason not to use fuses; high resistance connection between fuse and fuse holder generates heat(from volt drop). Breakers are much better. Look into Midnite Solar.

[MrWizard]

very similar

the one i installed looks like this

[westend]

I use this in that location. It is made to operate like a switch. Probably similar to what Mr Wiz is using.

[MrWizard]

try marine grade DC circuit breakers
i tried car audio fuses, but most are made in china and the fuses holders got HOT
even the melted the plastic holder
i dont if its the metal in the fuse holders contact surface or the fuse metal ends
or wether its the combination

i switched to 40amp DC circuit breaker
when i want to disconnect the panels , push one button to disconnect
one lever for resest/turn on

[Dirtpig]

I think the problem is the lack of surface area on the small fuses and in the (cheap) holder itself. Car audio amplifier equipment is pretty high quality as some require 100+amps so im hoping this change will help. Im changing to a maxi type fuse, and the controller manual states 60amp maximum size fuse so i am going to install a 50amp fuse from controller to battery. 2oldman, you are correct on the panels to controller fuse. even in the controller manual it doesn't specify putting a fuse in that connection. One reason why it put it in is that i wanted either a switch or a fuse i could yank out so that i could easily disable the panels if i wanted to.

[2oldman]

Unless you're really enamored of having fuses from PV to controller, they're not needed. Likely a poor connection, kinda like having clip-on jumper cables...not really much surface area there.

[Crazy_Ray]

Says 300 in profile

[DrewE]

Sounds to me like you likely have a poor connection at the fuseholder. Possibly removing and reinserting the fuse a few times would clear it up, at least temporarily. It may also be a wire connection to the fuse holder that needs attention.

Using a better quality fuse holder (or perhaps just one more appropriately specified for the environment) could, at least in some cases, give a more permanent solution. Whether the replacements you've ordered are better or not is of course impossible for me to deduce without further information (and maybe not even then).

[pianotuna]

How many watts is the solar system? What voltage?