Wire and Fuse Sizing

[john61ct]

Between Class T and ANL the latter are cheaper, easier to mount different sizes in the same block and yes more popular.

But Class T react more quickly, for some gear that's critical.

[rgleason]

Ok that is a good point. So the major load on the battery for our boat is the starter! No windlass and no watermaker, so I think I want the fuse type that is a little slower but meets AIC.

Would there be a reason to use a faster T as the main fuse on the house?

[john61ct]

Prolly not, long as electronics inverters etc are well protected.

Such devices often spec their CP requirements.

[Zil]

Fuses protect the cables and wires.

[FlyingScot]

Follow-up:

From Boat Owner's M & E Manual:
...maximum sustained amperage on the circuit, and not some "typical" or "normal" operating load. This maximum sustained amperage is the first key factor in cable sizing calculations. p.211

Ensuring Safety. It is only by putting these four factors together---the maximum sustained load on a circuit, the maximum ambient temperature of the space through which the cable will pass, whether or not the cable is bundled wither other cables, and the temperature rating of the cable insulation---that a proper choice of a cable can be made for a given application. p.213

[GordMay]

ANL Fuses vs. Class T Fuses
These two fuses are the most common high amperage fuses used in marine applications and there are significant differences between the two:

ANL Fuse Advantages:
Lower cost than Class T fuses
Available in a wider amperage range than Class T Fuses
Single mounting hole dimension allows all ANL Fuses to be used with the same fuse block
Fusible link window gives visual indication of fuse being blown
Ignition protected—safe for installation aboard gasoline powered boats

Class T Fuse Advantages:
The only UL 248-15 listed fuse commonly available in the marine industry *
Very fast response to short circuits protects high-amp electronic equipment such as inverters
20,000 Amp Interrupting Capacity

Pg 37 ➥ http://assets.bluesea.com/files/reso...Protection.pdf

UL248 ➥ http://ep-us.mersen.com/fileadmin/ca...248_CSA_EN.pdf