Melting fuses ...

[TDTROLL]

So iv recently changed around my lighting set up and added a 42" duel row curved light bar and ever since iv been chasing fuse issues ...
Off the main battery I have a maxi fuse that powers a fuse block
Off that fuse block I run all my lights
5640856409

So that fuse block runs
Hid headlights
Hid driving lights
22" light bar
42" light bar
56410

I started off with all 15amp fuses in the block but straight away popped a couple so replaced them all with 20amp
I also popped the 40amp maxi fuse so replaced it with a 50amp maxi

On a night drive I noticed my 42" bar was flickering so stopped to suss it out when I found the 20amp fuse melting but didn't pop so I chucked a 30amp fuse in ... That was all good for about half an hour until my 50amp maxi fuse started melting the holder then eventually popped ...
At that stage I Jammed an 80amp maxi in the badly malted holder and drove home on low beam

WHATS THE GO ???
Why are they melting and not popping to start with and what size fuses should I be running ? Or is it because my fuse holders aren't upto the task ???

[KiwiAngler]

Fuses are designed to 'pop' if they are overloaded (more current being used than the system is designed for) or there is a short.

Putting a 'bigger' amp fuse in is the last thing to do. All you are doing is allowing the overloaded situation to continue. Doing what you are doing could possibly lead to a fire.

I would be:

1) working out the amperage being drawn through the circuit and then determining the wire gauge and fuse required for THAT amperage.

Question: "are you running all your lights at the same time? If so then you need to ensure that the circuit (wires, fuses, fuse holders etc) are capable of withstanding that amperage being drawn at the same time.

Sounds to me as though you have too much draw for the system you HAD in place originally - you may need to go bigger on the wiring etc

That would be my approach

[threedogs]

what wattage are the head lights and driving lights,
The top bar is about 240 watts, so 20 amps there alone
BTW the bar on top of the bull bar is illegal well in Vic anyway.
Surely the roof top light bar and HID driving lights gives you enough light.
You wouldnt notice the one on the bull bar would you.
Make sure you have the correct wire size as well

[4bye4]

I have had fuse holders heating/melting at work from time to time. Assuming the ratings are correct, it has been the fuse holder not making good contact with the fuse, making a high resistance join where the fuse plugs in.

[TroutNut]

All the above...melting fuses sounds like high resistance = heat..parrot parrot.
How big is your alternator? My rb30 runs a 60 Amp, so 720watts at 12v minus a couple hundred watts for vehicle globes, fans, engine n all that leaves not much for a stack of lights.
Id be inclined to find the total current your lights use incase the alt fries.
Watts divided by 12 (the voltage) = approximate Amps needed:blowup:

[Nightjar]

Fuses are designed to 'pop' if they are overloaded (more current being used than the system is designed for) or there is a short.

Putting a 'bigger' amp fuse in is the last thing to do. All you are doing is allowing the overloaded situation to continue. Doing what you are doing could possibly lead to a fire.

I would be:

1) working out the amperage being drawn through the circuit and then determining the wire gauge and fuse required for THAT amperage.

Question: "are you running all your lights at the same time? If so then you need to ensure that the circuit (wires, fuses, fuse holders etc) are capable of withstanding that amperage being drawn at the same time.

Sounds to me as though you have too much draw for the system you HAD in place originally - you may need to go bigger on the wiring etc

That would be my approach

Definitely higher gauge wire required or you're going to see your pride and joy go up in smoke.
As mentioned increasing the fuse size is allowing more amperage which in turn is overloading your wiring.
Think about it as a plumbing set up. Your garden retic system doesn't quite reach all your garden so you think reducing the pipe diameter will fix this. Reducing the pipe dia will increase the pressure but actually reduce the flow. If the pressure from your pump is too great for the reduced piping size the piping will burst. Exactly what is happening with your 12V system, your wiring/pipe size is undersized for what the applied pressure/amperage being delivered.

[macca]

it has been the fuse holder not making good contact with the fuse, making a high resistance join where the fuse plugs in.

This is the most likely answer.

Be sure the sockets give a firm fit to the fuse (possibly can squeeze them tighter with pliers)

Make sure the blade of the fuse is in the socket, not beside it. The way the sockets are offset in you pic looks that might be the problem.

It could have been a faulty connection in the fuse holder itself, also the cable feeding those fuse types are fairly large so can handle more amps that most lighting set ups.

[the evil twin]

1. The 15 amp fuse that were popping were doing so because the circuits were drawing more than 15 amps.
The large light bar could easily be drawing up to 25 amps on start up
You don't mention the HID ratings but they also could be drawing 15 to 20 amps on start up depending.

2. Hard to tell from the wiring but some of the cables off that fuse block do not look like they will handle the current.
That means the cable will heat up and draw even more amperage

3. Your fuse box supply cable could have up to 70 or more amps on start and 50 amps constant.

4. As mentioned by others, the "melting" is caused by excessive current at a resistance at the contact points, as this gets hotter the resistance gets higher and so does the temp so it just keeps getting worse.

If you want to keep the existing setup (1 maxi to 1 x 6 way fuse box) then you need to do the following;
1. Supply cable 6 B&S from battery to fuse box
2. Maxi Fuse 80 Amp and solder as well as crimp the splices if possible
3. One cable per fuse at the fuse box, 15 amp for Main beams, 15 or 20 amp HIDs, 20 amp small bar, 30 amp min for large
4. The Mains, and HIDs will be OK on 6mm and also prob the small bar but the large bar will want bigger.
5. Once you have that sorted turn everything on and check for "hot spots" at fuses and splices anything hot is faulty (laser temp gun is great if you have one)
6. When you are out on the road don't start everything at once as start up currents can be very high momentarily and pop the maxi.

[TroutNut]

Could use a fuse box that takes the large fuses, either the PAL type or the big flat blades that are about 1 inch wide, that'd increase the surface area of the contact. As ET says, id solder joints where possible.

[TDTROLL]

Cheers guys for your responses what fuse block can Handel the power I'm drawing ?
my 42" light bar is 400w
22" light bar is 80w
HID driving lights are 55w
Unsure of HID headlights
What size cable & fuses should I be running keeping in mind those specs ???

[the evil twin]

Jeezus... 400 watts!!!
That will pull over 40 amps momentarily on start up.

I would wire that on a totally seperate circuit all it's own.
Hope you have a high current relay on it, a standard 30/40 won't like it for very long

[fracster]

my 42" light bar is 400w
You sure about that pal, LEDs don`t draw that much power.

Happy to be proved wrong,of course.

[TDTROLL]

56442
Yea mate I believe so

[mjr350]

Go get some single stackable fuse holders. They're neat and tidy and can be tucked away from view leaving more room in the engine bay.

[macca]

56442
Yea mate I believe so

Sheesh 33.34 amps at 12 volts wow

[mudnut]

I thought the whole idea of LEDs is to reduce the current flow. It would must be worse than looking into the sun on a summers day, if that light bar was coming at you on a dark night.

[Winnie]

I thought the whole idea of LEDs is to reduce the current flow. It would must be worse than looking into the sun on a summers day, if that light bar was coming at you on a dark night.

To create that much light with HID, you would be up for around 800W, and halogen would be over 3000W
That's a huge current draw but man that thing must be insane bright!

None of the cables coming in or out of that fuse block though will support 35A though, need to put much thicker wires in for that and a high current relay.

[the evil twin]

snip...To create that much light with HID, you would be up for around 800W,

I tend to agree but hard to say exactly, it is a bit like comparing apples and oranges in a way.
LED has made some huge leaps in technology in the last 5 to 10 years but apart from improved ballasting HID has pretty much stagnated

Most freely available main stream LED's these days will do from 90 to 100 lumens per watt.

Some Hi Intensity LED today will do much better at around 150 to 200 and prices are plummeting but are still very expensive at the moment IE no way they are using 80 of them in that bar at $400 (indeed I am amazed they are using Oslon LED's at that price).

Last year Cree managed to crack 300 lumen per watt in a technology demonstrator... But... (I love buts)

Luminous flux / Light output – is the amount of light produced by a lamp and is measured in lumens (and is useless in many ways).
Illuminance / Light level – is the amount of light incident on a surface. It is measured in Lux (or lumens per square meter).
Luminance / Brightness – It is the amount of light reflected by a surface. It is measured in Candelas (or Cd/m²)

The human eye sees illuminance not luminous flux IE we see the light hitting a surface NOT what leaves the emitter
That means we "see" Lux not Lumen

Enter the concept of scotopic lumens and a factor called S/P ratio.
Photopic lumens as used by most manuf (useless) can be amended using this ratio which helps convert traditional Lumens into actual Lumens perceived by the eye under mesopic light conditions (night time driving) and gives a better estimate of the amount of illuminance.

LED's have an much higher S/P than HID so are much more efficient light for the human eye in relation to lumens claimed.
Given the LED technology curve HID in vehicles will be deader 'n Dinosaur Dung in 5 years or so

[fracster]

Wow, that thing must be bloody bright.
56442
Yea mate I believe so

[Bigcol]

I tend to agree but hard to say exactly, it is a bit like comparing apples and oranges in a way.
LED has made some huge leaps in technology in the last 5 to 10 years but apart from improved ballasting HID has pretty much stagnated

Most freely available main stream LED's these days will do from 90 to 100 lumens per watt.

Some Hi Intensity LED today will do much better at around 150 to 200 and prices are plummeting but are still very expensive at the moment IE no way they are using 80 of them in that bar at $400 (indeed I am amazed they are using Oslon LED's at that price).

Last year Cree managed to crack 300 lumen per watt in a technology demonstrator... But... (I love buts)

Luminous flux / Light output – is the amount of light produced by a lamp and is measured in lumens (and is useless in many ways).
Illuminance / Light level – is the amount of light incident on a surface. It is measured in Lux (or lumens per square meter).
Luminance / Brightness – It is the amount of light reflected by a surface. It is measured in Candelas (or Cd/m²)

The human eye sees illuminance not luminous flux IE we see the light hitting a surface NOT what leaves the emitter
That means we "see" Lux not Lumen

Enter the concept of scotopic lumens and a factor called S/P ratio.
Photopic lumens as used by most manuf (useless) can be amended using this ratio which helps convert traditional Lumens into actual Lumens perceived by the eye under mesopic light conditions (night time driving) and gives a better estimate of the amount of illuminance.

LED's have an much higher S/P than HID so are much more efficient light for the human eye in relation to lumens claimed.
Given the LED technology curve HID in vehicles will be deader 'n Dinosaur Dung in 5 years or so


now, can you explain that in common English for us "non - smart" people.............????????

[the evil twin]

now, can you explain that in common English for us "non - smart" people.............????????

LEDs are more gooderer and Lumens mean bugger all... sort of

[mudnut]

He means, oncoming drivers be like...

[TroutNut]

Sounds like you need big dual alts to start with. Or a long 240v lead.

[the evil twin]

Sounds like you need big dual alts to start with. Or a long 240v lead.

ROFL... maybe even 3 phase