Amps. wiring question

bluey

Seaman
Joined
Oct 31, 2010
Messages
70
Hi,

This is probably a silly question, but I'll ask it anyway.

When wiring a boat you need to know the current draw/amps of the item you are connecting to in order to determine the correct wire guage, and fuse sizes. Does this also apply to items on the engine, such as Oil pressure sensor, Water temp sensor, and Tach sensor? (my tach is the magnetic pickup type). I imagine the current draw for these would be very small, but they are all electrically operated and each has it's own circuit, so is there any consideration that should be applied to them to determine wire size and do they need fuses?

bluey.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Amps. wiring question

Hi,

This is probably a silly question, but I'll ask it anyway.

When wiring a boat you need to know the current draw/amps of the item you are connecting to in order to determine the correct wire guage, and fuse sizes. Does this also apply to items on the engine, such as Oil pressure sensor, Water temp sensor, and Tach sensor? (my tach is the magnetic pickup type). I imagine the current draw for these would be very small, but they are all electrically operated and each has it's own circuit, so is there any consideration that should be applied to them to determine wire size and do they need fuses?

bluey.

No, your ignition fuse at the instrument panel is sized to cover all those items.
 

Grandad

Lieutenant Commander
Joined
Jun 7, 2011
Messages
1,504
Re: Amps. wiring question

At some very low current level, you're only concerned with having enough current carrying capacity to blow the fuse protecting the system as opposed to "blowing" the wire if shorted. Also, even in circuits that might be protected with say only a 1/10 amp fuse, using a wire that small is typically not mechanically strong enough and terminations might break if you sneeze on them. Unless a wire is protected inside an enclosure or in a cable jacket, I wouldn't use less than a number 16 AWG for anything. - Grandad
 

Splat

Lieutenant
Joined
Jul 20, 2008
Messages
1,366
Re: Amps. wiring question

Don is correct, it was a hell of a question tho.

Bill
 
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