Adding 100w solar is a 10 amp fuse ok

[Odd-no-more]

Like the title will a 10amp fuse be enough for a 100w solar, the fuse is off the battery before the control.

 

[Sandancers]

Like the title will a 10amp fuse be enough for a 100w solar, the fuse is off the battery before the control.

I am going to fit a solar panel when the weather gets warmer.

I am going to fit a fuse in a weatherproof box on the roof. This fuse is to protect the wires which go from the solar panel down to the controller, so the size of the fuse should be sized to protect the wire, ie if the wire can carry 15A the the fuse should be say 10Ah. But of course the wire should be of the right size to carry the maximum current the panel can produce. So if your panel can produce 10A you need a cable capable of carrying 10A without overheating and then a fuse to protect that size of cable.

I am also fitting a fuse in the cable which goes from the controller to the battery. This fuse is sited really close to the positive terminal of the battery, it's job is to protect the cable from the battery in case there is a short on that cable as it goes to the controller. So calculations on the fuse size as above.

If you wanted to be really safe put in a fuse in the cable from the controller to the battery sited very near the controller. Same size as the one near the battery.

It's all about seeing where the current will flow from in the event of a cable short circuit and protecting the cable by a fuse.

So in answer to your question, what is the max current the panel can produce and work from there.

 

[Lenny HB]

Like the title will a 10amp fuse be enough for a 100w solar, the fuse is off the battery before the control.

Your fuse is at the wrong end of the cable, it should be close to the controller as that is where the current is flowing from.
Fuses are to protect the cable 10 amp will be OK.

 

[Sandancers]

Your fuse is at the wrong end of the cable, it should be close to the controller as that is where the current is flowing from.
Fuses are to protect the cable 10 amp will be OK.

Would you not agree with the fuse layout I gave in #2 ?

 

[funflair]

Your fuse is at the wrong end of the cable, it should be close to the controller as that is where the current is flowing from.
Fuses are to protect the cable 10 amp will be OK.

But that doesn't protect the cable if there is a short between the battery and the controller, rightly or wrongly ours is fused where the solar regulator cable joins the +ve bus bar and the original controllers had a fuse in as well (not sure Victron does).

Basically it's connecting a power source to a power source so I can see an argument for a fuse at either end

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[Lenny HB]

Would you not agree with the fuse layout I gave in #2 ?

You don't normally fuse solar panels it is not required but most of us fit a fuse by the controller as a convenient way of disconnecting the panels.

 

[Lenny HB]

But that doesn't protect the cable if there is a short between the battery and the controller, rightly or wrongly ours is fused where the solar regulator cable joins the +ve bus bar and the original controllers had a fuse in as well (not sure Victron does).

Basically it's connecting a power source to a power source so I can see an argument for a fuse at either end

I would agree it is wise to have one at the battery end as well as the battery is an infinite source of power.

 

[funflair]

You don't normally fuse solar panels it is not required but most of us fit a fuse by the controller as a convenient way of disconnecting the panels.

Is that on the basis that the cable from the solar is more than capable of handling even a dead short on the panel supply side?

 

[Odd-no-more]

I have to confess, I don't have a MOHO

 

[Odd-no-more]

Following on from my last post, the solar is for my caravan and it's a suitcase type, to connect to the battery I fitted a cigar lighter type socket to the battery that's where the fuse is.

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[funflair]

Following on from my last post, the solar is for my caravan and it's a suitcase type, to connect to the battery I fitted a cigar lighter type socket to the battery that's where the fuse is.

So the fuse is the battery end of the cigar lighter socket wiring, I would say that was fine "but I know nothing" there is most likely a fuse on the back of the panel anyway.

 

[Lenny HB]

Is that on the basis that the cable from the solar is more than capable of handling even a dead short on the panel supply side?

You can short circuit a solar panel and it won't cause any problems.

 

[autorouter]

Is that on the basis that the cable from the solar is more than capable of handling even a dead short on the panel supply side?

As Lenny HB says. If you look at the solar panel specs, you will see 'Imp', the amps at the maximum power point, ie the normal working amps. Also there will be 'Isc', the amps when short circuited. Isc is not much more than Imp, so any fuse that is OK for Imp would never blow if it increased to Isc.

 

[chaser]

Considering how easy it is to put in fuses , I would have one at both ends , as I have on mine, as obviously on a solar to battery set up it's live at both ends if you get some sort of break in the cable.

 

[chaser]

These are mine I have similar at the other end

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[funflair]

I don't know if this is right or wrong but it's certainly interesting

How/When to Fuse a Solar Panel Array

This blog post is going to teach you how to determine when and if you need to add in-line fuses when designing a camper solar array. Sometimes you need to fuse your solar array, and

www.explorist.life

 

[The Wino]

I would agree it is wise to have one at the battery end as well as the battery is an infinite source of power.

Not quite infinite but enough to cause a fire. I used the prewiring on mine and have to confess assumed the battery end would be fuse protected rather than checked I did put a fuse near the controller to isolate it if necessary but inside the motorhome.

 

[Coolcats]

Your fuse is at the wrong end of the cable, it should be close to the controller as that is where the current is flowing from.
Fuses are to protect the cable 10 amp will be OK.

Just a thought in general terms a fuse is not just to protect a cable but if there is an overload in a circuit which may or may not include a length of cable. I am not an electrician but observing where manufactures place a fuse it appears more about overall overload protection which may be at any point along a circuit from the power lines incoming main fuse, fuse box, plug and internally with a device.

 

[Lenny HB]

Just a thought in general terms a fuse is not just to protect a cable but if there is an overload in a circuit which may or may not include a length of cable. I am not an electrician but observing where manufactures place a fuse it appears more about overall overload protection which may be at any point along a circuit from the power lines incoming main fuse, fuse box, plug and internally with a device.

Covered in earlier posts.

 

[autorouter]

I don't know if this is right or wrong but it's certainly interesting

He says that whether you need to add fuses depends on the 'Maximum Series Fuse Rating' parameter. That supplier Rich Solar gives this in the spec list, I don't know anyone else that lists it. I'm sure he's thinking about arrays of 4 or more panels, so not applicable to most MHs anyway.

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