[giftedk]

Working out the back of the van and notice the fuse to switch was getting hot and smoking, anyone got any ideas as to what this could be ?

Many thanks

[Positivity]

Fuse too small a rating for amount of current being drawn?

[giftedk]

Thanks positivity, im using green 30 ones. I heard you can use higher but not lower , or is it the other way round ?

[AuRavelling79]

Where the fuse goes in - are the contacts clean with no build up of dirt, verdigris or somesuch. Thoroughly clean the contacts.

[Spruce]

Where the fuse goes in - are the contacts clean with no build up of dirt, verdigris or somesuch. Thoroughly clean the contacts.

^^^ what he says. I would replace the fuse holder as heat damages them. Bad contacts cause heat due to resistance.

Only use the right fuse. Too small will blow and too big will do damage if there is a fault. Fuses are there to keep your electrical equipment working and protect the circuit from overload at the same time.

[paulben]

If you are stuck for a fuse you can go lower but never higher

[giftedk]

Cheers lads, all sorted

[Ian Sheppard]

As above you should not over rate a fuse, Fitting a higher rated fuse can be dangerous as it allows a fault to heat up.

A fuse(s) is needed in any electrical system (AC or DC). These protection devices react to the amount of heat being produced by electricity passing through wires and/or components. They are used so as to protect wires and components from the extreme heat produced should there be an electrical overload or short circuit.

When a short or overload occurs, the amps being drawn spike and this increases the heat produced in the wiring and components. When this occurs, a fuse or circuit breaker reacts almost instantly to stop the flow of electricity in the circuit and thereby stopping heat production.
You should never exceed the fuse rating advised by the manufacturer. For a fuse to open in a fault condition almost instantly (a few hundred milliseconds ) it can require current of 2.2 to 3 times the rating of the fuse. For our controllers we recommend 7.5 amp fuses so the actual current to open the fuse may be as high as 22.5 amps over rating the fuse is dangerous. (Check the manufacturers instructions for correct rating)

In very rare cases if current is only slightly above or close to the rating of the fuse for prolonged periods there is not sufficient heat or current to blow the fuse, in this case the heat can build up and cause the fuse to melt.
For example a 15 amp fuse will happily supply current up to 15 amps but will not blow. (to blow it could require current of up to 45 amps) The fuse will however gradually get hot over time in testing at Spring I have seen a 7.5 amp fuse heat to 62C and not blow
Without PROPERLY-SIZED FUSES, this quick break in the circuit would not be possible, and damage to components and even FIRE could result.
If you are having a problem with fuses "blowing" please know that these devices are doing their job! It is important that you NOT replace a fuse or breaker with a higher-rated one. Check the circuit for shorts or overloads.

Damaged, rusted or worn connectors
Damaged cable
Bare cables touching each other or to metal panels
Poor connection (example would be insulation not stripped back)

[sunshine windows]

Great post Ian, could prevent a fire or save somebody's life 👍

[*Hector*]

So.... banging in a rust nail is not proper procedure then?? 

[Frankybadboy]

So.... banging in a rust nail is not proper procedure then?? 

what you do with your wife is your business

[*Hector*]

Feeling a bit better now then Frankie ?? 

[Frankybadboy]

Feeling a bit better now then Frankie ?? 

Sir frankie to you hector and dont forget it


otherwise i make you sit on the settee with gary eating biscuits

[*Hector*]

That would be worse than torture... 

Watching the blurred motion of Chunky's hands moving from packet to gob.....

Mind you... the packet would be gone in 60 seconds...