Do we need fuses?

[Simon B]

Forgive the title, I think we do but am interested in technical opinion;

Do you actually need a fuse in the circuit for individual items or can one rely on the inline fuses (if you remember where they are) or use one fuse to cover the whole lot?!

There is a debate currently within our club, I want to hold out and fit a fusebox for individual items (fused separately).

Others feel a Rib is adequately protected with one large fuse.

Others still think that the surface mounted glass cartridge fuses by the switch on the face of the console are good enough and trouble free.

[ashbypower]

I’m with you fuse everything independently a far safer and sensible option. Ask the doubters this. Why do’s a house have a main fuse (100 Amp+) then fuse individual circuits and finally the appliance?

Regards

Brian

[Cookee]

Originally Posted by ashbypower

I’m with you fuse everything independently a far safer and sensible option. Ask the doubters this. Why do’s a house have a main fuse (100 Amp+) then fuse individual circuits and finally the appliance?

Regards

Brian

When the bilge pump blows the main fuse and it's dark how are you going to see to fix it?

[DJL]

The point of a fuse is to stop to much current being drawn through a piece of wire and melting it which could lead to a fire. If you just have say one 15amp fuse for all your electronics, then it’s possible that you could be asking the 22gauge wire running to your faulty GPS to carry 15amp when it’s only designed for 3.

Not to mention your don't really want to blow the only fuse at night and loose all your lights, GPS, depth sounder, bilge pump.... much better to just loose one.

I would highly recommend fitting a fuse box and fuse everything independently.

[Jono]

..or perhaps spend a few "sheckells" and buy some nice circuit breakers. Easy to re-set in a difficult sitaution.. once you have correct the problem... much easier.. in my opinion.. than feckin' about with fuse boxes in the wet and cold...and usually dark.... marine ones are available... just got to find them.. when I remember where I saw them... and I'm going to retrofit them to my boat when I can find the motivation to get off my arse and do it....

[Rogue Wave]

Fuses Yeah, MCB's no! You can tell that Mr Jono lives inland!

My experience of MCB's is that they deteriate quite badly over time and fail to function, they esentialy don't like the salt content in the air.

[DJL]

You can buy a little circuit breaker blade fuse that fits in a normal blade fuse box.

[Jono]

Originally Posted by Rogue Wave

Fuses Yeah, MCB's no! You can tell that Mr Jono lives inland!

My experience of MCB's is that they deteriate quite badly over time and fail to function, they esentialy don't like the salt content in the air.

I saw that... what? Even the ones tucked inside a console in their own little, snug housing? I bow to your more extensive experience.... especially at "fings wot brake"... but I've seen problems with blade/glass type fuses corroding in their sockets and the solution of filling them with petroleum jelly.. doesn't seem quite right.... anything that relies on a push fit in a hostile environment is a potential.. .. weakness that I'd like to avoid ...where possible.....

[Simon B]

Thanks chaps that's just what I'd hoped you'd all say. One last question, I believe it is a sensible idea to keep the sounder and GPS circuits separate as sounders can draw larger currents is this correct? (the eagle cuda we have is fused with a 250v fuse as supplied by Eagle)

[DJL]

It's sensible to keep the sounder and GPS circuits separate because you only lose the faulty device not both.

However, a newish depth sounder will only use a couple of amps - probably about twice a GPS.

[yoyo]

In addition to a main distribution board, have just fitted this 4 way blue sea switch set that has a positive feed buzz bar and individual blade type fuses for each switch.

http://www.bluesea.com/

This insures that each electrical item is protected by the correct fuse rating. I have also installed a heavy in-line master fuse next to the main battery switch. After taking advice from this forum, all my electrical installations have used Blue Sea components.

Bob.

[Jono]

Anyone got any experience of these "waterproof" puppies in marine use... http://www.chandlery.net/groups/3130...tbreakers.html ... the bloke on the narrow boat at the back of the works swears by 'em....

[Scary Des]

Originally Posted by Jono

Anyone got any experience of these "waterproof" puppies in marine use... ....... the bloke on the narrow boat at the back of the works swears by 'em....

Originally Posted by from site

Fully waterproof (IP66) circuit breaker.

IP66 does not equal fully waterproof, should be IP68, or more Des

[Jono]

scrub that... I've found the info..ta.. I'll settle for "66" inside my console.. if it floods up to that level...I'm in deeper doo-doo than worying about my trips....... http://www.okw.co.uk/technical/IP-ratings.htm

[Scary Des]

IP codes
Degrees of Protection provided by enclosures.
An IP number is often used when specifying the environmental protection afforded by enclosures around electronic equipment. These ratings refer to specific tests. The IP number is made up of two components as follows: IP44 The first number refers to the protection against solid objects and the second against liquids. The higher the number the better the protection. see below for a summary.

IP Protection Number Summary

FIRST NUMBER

0 No protection
1 Protected against solid objects up to 50mm eg accidental touch by hands
2 Protected against solid objects up to 12mm eg fingers
3 Protected against solid objects up to 2.5mm (tools and wires)
4 Protected against solid objects up to 1mm (small tools and wires)
5 Protected against dust, limited ingress (no harmful deposit)
6 Totally protected against dust

SECOND NUMBER
0 No protection
1 Protection against vertically falling drops of water eg condensation
2 Protection against direct sprays of water up to 15 degrees from vertical
3 Protection against direct sprays of water up to 60 degrees from vertical
4 Protection against water sprayed from all directions - limited ingress permitted
5 Protected against low pressure jets of water from all directions - limited ingress permitted
6 Protected against low pressure jets of water (use on shipdeck)- limited ingress permitted
7 Protected against the effect of immersion between 15cm and 1m
8 Protected against long periods of immersion under pressure
Note that there is a third number which is commonly omitted which refers to protection against mechanical impacts.

[Jono]

..ah.. the speed of the edit has defeated the mighty Des..... .. I like the definition of "1".. Protection against large foreign bodies .. presumably that means if I tool up with "IP 1"... the Yanks can't invade my boat..... sorry.. childish, I know.. it just amused me....

[Scary Des]

Originally Posted by Jono

..ah.. the speed of the edit has defeated the mighty Des.....

Too fast for me

[Scary Des]

IP00 is an interesting one which could be applied to lettuce and IP21 which could be a applied to a cocktail umbrella Des

[codprawn]

Originally Posted by Simon B

Thanks chaps that's just what I'd hoped you'd all say. One last question, I believe it is a sensible idea to keep the sounder and GPS circuits separate as sounders can draw larger currents is this correct? (the eagle cuda we have is fused with a 250v fuse as supplied by Eagle)

What's volts got to do with it???

Remember it's the amps wot cramp!!!

[Simon B]

Originally Posted by codprawn

What's volts got to do with it???

Remember it's the amps wot cramp!!!

I realise that, just seemed strange that they couldnt find the right size 12v fuse.