Bowthruster Fuse

[pandos]

My bowthruster has a 4.3kw motor. My understanding is that at around 12 v this would require a supply of something like 360 amps.

It is fused with what appears to be a 200amp fuse. I understand it was working fine in the past with this setup.

Am I missing something?

 

[Boater Sam]

Fuses don't "blow" instantaneously at the current rating printed on them. They carry the limited excess current for a time and melt slowly. They only go bang if you hit them with a huge overload.
That is a slow blow fuse too.

You probably never achieve 360A due to voltage drop on cables etc. and battery voltage slumping under load.

 

[PaulRainbow]

My bowthruster has a 4.3kw motor. My understanding is that at around 12 v this would require a supply of something like 360 amps.

It is fused with what appears to be a 200amp fuse. I understand it was working fine in the past with this setup.

Am I missing something?

What make/model of thruster ?

200A seems a bit low if it's a 12V system, sure it's not 24V ?

 

[Plum]

My bowthruster has a 4.3kw motor. My understanding is that at around 12 v this would require a supply of something like 360 amps.

It is fused with what appears to be a 200amp fuse. I understand it was working fine in the past with this setup.

Am I missing something?

My 4kW 12v Volvo Penta thruster motor had a 300A fuse. ( I am selling the motor/solenoid as now fitting a complete new thruster due to a failed gearbox.)

 

[pandos]

What make/model of thruster ?

200A seems a bit low if it's a 12V system, sure it's not 24V ?

Definitely it's a 12v system.

It's a Sleipner/ Sidepower thruster from about 1989. I have never heard it run as I disconnected all the heavy cabling that I couldn't identify or or need before I moved the boat...( It was a huge mess)

It's only recently that I took out that fuse to get a better look and was surprised to see that it is only 200a it's a seriously beefy yoke with a holder to match...along with plenty of exposed metal.

I'll be moving it or at least putting it into an enclosure. Probably I should pick up a spare or maybe a slightly stronger one if the holder is the same.

 

[PaulRainbow]

Definitely it's a 12v system.

It's only recently that I took out that fuse to get a better look and was surprised to see that it is only 200a it's a seriously beefy yoke with a holder to match...along with plenty of exposed metal.

I'll be moving it or at least putting it into an enclosure. Probably I should pick up a spare or maybe a slightly stronger one if the holder is the same.

What's the make/model of thruster ?

 

[pandos]

What's the make/model of thruster ?

Sleipner/ Sidepower a better photo..

 

[PaulRainbow]

Definitely it's a 12v system.

It's a Sleipner/ Sidepower thruster from about 1989. I have never heard it run as I disconnected all the heavy cabling that I couldn't identify or or need before I moved the boat...( It was a huge mess)

It's only recently that I took out that fuse to get a better look and was surprised to see that it is only 200a it's a seriously beefy yoke with a holder to match...along with plenty of exposed metal.

I'll be moving it or at least putting it into an enclosure. Probably I should pick up a spare or maybe a slightly stronger one if the holder is the same.

The fuse is way under rated, i'm surprised it works at all. Sleipner specify that the current 4.4kw thruster should have a 400A ANL fuse. Maybe a change would be better ?

For instance; 200A/300A/400A ANL Fuse Set w/ Fuse

Covers are available for the current NH! fuse ; Mersen L201881 MERSEN (FERRAZ) NH-1 TERMINAL SHIELD | Kempston Controls but the ANL looks a better choice.