Fuse question

Submitted: Tuesday, Jul 05, 2005 at 16:10
ThreadID: 24453 Views:2484 Replies:5 FollowUps:1
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My fuses are getting warm. I know this will be costing power to the battery, but is it a hazard please?
I am charging a battery with the charger cables connected to 50cm of 8mm wire, which come direct from the battery terminals. These cables each have cylindrical 'glass type' 25 amp fuses near the battery.
The charger cables connect to the battery terminal cables via an Anderson 50amp plug.
The charger is providing 13 amps.
None of the cables get warm at all - only the fuses.
Does anyone know if this is a dangerous situation please? I can put up with current loss.
I can only guess that a heavier duty fuse set up could solve the problem, but the re-wiring would be quite a major task because of its' situation in the caravan.
Thanks all,
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Reply By: PhilRob - Tuesday, Jul 05, 2005 at 16:57

Tuesday, Jul 05, 2005 at 16:57
A hot fuse could possibly be a bad connection between the fuse and the fuse holder
check that connections are good, also don't put in larger fuses than the
recommended amperage, these are to protect the circuit, if larger fuses are installed then something else becomes the fuse and this usually means smoke and
fire. If you are unsure, have it checked out by auto elec.
AnswerID: 118953

Reply By: Richary - Tuesday, Jul 05, 2005 at 17:03

Tuesday, Jul 05, 2005 at 17:03
I had this problem on the tyre compressor, the fuse connector was getting very hot and in fact melted the solder connection of the fuse wire inside the fuse. Turned out to be a crook connection between the wire and terminal inside the fuse holder. Replacing the inline fuse fixed it up nicely.
AnswerID: 118954

Reply By: drivesafe - Tuesday, Jul 05, 2005 at 17:37

Tuesday, Jul 05, 2005 at 17:37
Hi Dave, it’s a common problem for inline glass fuse holder to get hot.

There are two types on inline holder. One has clips that surround the metal ends of the glass fuse and this type usually works well.

The more common inline glass fuse holders use a spring to keep contacts connected to either end of the glass fuse, these are the ones that heat up.

The quickest way to temporarily resolve the problem it to open the holder and twist the fuse aggressively against the contact. Note this is only worth doing if the glass fuse is the type that has soldered ends.

By twisting the fuse and contact in this manner, you both clean the contact surface and spread the solder slightly which increases the contact area.

As stated above, the is a temporary fix and ultimately you should try and replace the inline glass fuse holder with a blade fuse type inline fuse holder. Blade fuses, because of the way the contact surfaces come together make for a better and longer lasting connection.

Cheers and hope this helps
AnswerID: 118958

Follow Up By: Member - Davoe (Widgiemooltha) - Wednesday, Jul 06, 2005 at 01:26

Wednesday, Jul 06, 2005 at 01:26
get the black baka light type inline not the white plastic few bucks more but problem solved
FollowupID: 374197

Reply By: Peter 2 - Tuesday, Jul 05, 2005 at 18:53

Tuesday, Jul 05, 2005 at 18:53
Something to remember with blade fuses is that they are usually alloy and they oxidise over time especially if they are inserted into brass holders (which they usually are). This leads to poor contact, heat and eventually melted fuse holders.
I try and remove them all once a year, scrape the spades to a shiny surface and reinsert.
AnswerID: 118969

Reply By: geocacher (djcache) - Wednesday, Jul 06, 2005 at 15:47

Wednesday, Jul 06, 2005 at 15:47
Glass fuses are fairly useless at high amperages.

Change them for a better quality of fuse.

8mm wire? You couldn't get a decent fuse holder with crimps that large for glass anyway. Are you sure it isn't 3 or 4mm wire with bucket loads of insulation around it to make it look impressive - ala kmart jumper leads?

If it is truly 8mm wire go into an electrical wholesaler and get a buss style blade ended fuse in the 25 amp range and the appropriate fuse holder which generally accepts wire conductor up to about 8-10mm dia.

Get a spare fuse or two to suit at the same time.

Codan use similar fuses on their wiring harness for their HF radios.

Heat occurs as a result of resistance, and at higher currents = huge voltage drops.

AnswerID: 119126

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