Fire in the boat

[tabledancer]

After seeing the effects of a servo fire inside the WTC of my new to me Type VII I decided to refit the foward wireing harness by adding a few things.One of the additions was a fuse wired into the harness in the forward bay of the WTC.The problem is I don`t have any idea what amp rating fuse to go with.I`m running 2 Graupner 400`s,3 servos,air pump,and I`ve added a lighting system with 3 LEDS.It is a 6v system with 2 6v gell cells with 5.0 amps each.I`ve also added a magnetic on/off switch.The fuse holder is for the blade type fuse.



TD

[crazy ivan]

Re: Fire in the boat

TD,
Ideally, each branch circuit should have its own fuse of appropriate size, just as you would see in the way your house is wired. Are your motors geared down? Does each have its own esc, or are they wired together off a single esc? A 400 motor geared down 3:1 might typically pull around 4 amps under full load. A 7.5A fuse to each esc ( or a single 10A to 15A if wired together) should handle it and allow for current surges. Just make sure the wiring is heavy enough to carry what the fuse is rated for.

The rest of your equipment draws much less current and is likely connected with much lighter wire. The servos probably pull no more than 1 amp or so all together, so you might combine them with the LED circuit (which likely pulls less than 100mA). A 2A or 3A fuse should do for this branch. Personally, I put my pump on its own fuse. Air pumps used for RCABS, if thats what you have, typically only draw around 1/4 amp, so I use 2A fuse to allow for any surges when the pump starts. I also like to incorporate a master fuse at the battery that can handle the combined loads, say 10A to 15A. Also, those blade fuses of the automotive type come in two physical sizes. I like the smaller ones to save space.

Keep in mind that if you just go with a single fuse for everything, a short in the lighting circuit will burn up that thin wiring long before the fuse (which is rated for the motor current) blows.
Hope this helps

[tabledancer]

Re: Fire in the boat

Thankyou.I think that I will go with a 15 amp fuse which is the smaller blade fuse.



TD

[horseman]

Re: Fire in the boat

Hi all,

Hi I'm new on this forum but I feel the need to jump in this one,

I have only one remark/suggestion i want to share, in my subs, an Engel Lafajette I don't use a fuse at all and in my Engel Gato I use separate fuses for the dive system, main propulsion, lights ,Radar and periscope air pumps and not one single fuse, because if that one blows your sub will be dead in the water.

Its a tricky decision to make what will be worst or better. and it also depends what space you have to get your fuses in.
This the inside of my Gato.




As you can see its a tight fit even in a Sub from almost 2 meter.

Just my two cents,

Jan,

[Guest]

Re: Fire in the boat

Unless a fuse is underrated, it shouldn't blow unless something is seriously wrong. I would sooner have a boat dead in the water than an internal fire burning out the innards of the boat.

Engel tend to incorporate a fuse on the board of their electronic circuits- it takes the form of a thinner PCB trace, so you don't need to fuse their stuff.