SeaTalk Power?

[nigelmercier]

[UPDATE in Post #11]

I'm slightly embarrassed that I have to ask this question, but it has only just occurred to me.

I have several Raymarine ST60 instruments, plus an ST6000+ Autopilot controller driving a Type 100/300 Course Computer (not sure which, it doesn't say); I imagine this is a common setup.

I'm fairly certain the 100/300 has a permanent power feed (it is fed via a large, independent breaker, 20A I think); I also have a separate switch that turns all the instruments on.

Given that the 100/300 is connected to the ST60 instruments via the SeaTalk bus, and is also permanently powered, how is it that I can turn the instruments off?

 

[prv]

Because when connecting separately-powered items like autopilots and plotters, it's not mandatory to also connect the power wire. I do power my seatalk bus from the pilot, but it sounds like yours is separately powered which is also a legitimate option.

Pete

 

[nigelmercier]

Because when connecting separately-powered items like autopilots and plotters, it's not mandatory to also connect the power wire...

Thanks Pete, I wondered if this may be the case.

I'm considering fitting a relay in the main power feed to the 100/300, to turn it on only when my instruments are on.

Thoughts?

 

[d4raffy]

Thanks Pete, I wondered if this may be the case.

I'm considering fitting a relay in the main power feed to the 100/300, to turn it on only when my instruments are on.

Thoughts?

I like to leave my instruments on (while at anchor depth, wind, etc for alarms) but turn the AP off to conserve power. So a split supply works for me ....

 

[prv]

I'm considering fitting a relay in the main power feed to the 100/300, to turn it on only when my instruments are on.

I get the same effect by powering the Seatalk bus from the pilot. The circuit at the panel is labelled "Instruments & Autopilot", fused at IIRC 15 amps, and wired only to the S1 course computer. The computer then supplies power onto the Seatalk bus via a 2-amp fuse next to the terminals inside the case (and there's a label next to the main fusebox pointing this out). The Seatalk bus powers all the instruments (including a small Lowrance 4m plotter on the binnacle) but the power wire is not connected where the Seatalk goes into the main plotter.

This would be my choice if starting from scratch (which I essentially was when I re-wired most of the boat) but I imagine your relay idea would involve less re-routing of cables. You will of course have the constant drain of the relay coil whenever the instruments are turned on; I don't carry relay specs in my head to know off-hand how significant this would be.

Pete

 

[prv]

I like to leave my instruments on (while at anchor depth, wind, etc for alarms) but turn the AP off to conserve power. So a split supply works for me ....

Makes sense, and older, larger models of Raymarine computer had terminals for a hard on/off switch so that you could do this even if wired from a single supply. I tend to assume that in standby mode the pilot computer consumes minimal power and not worry about it, but I admit I've never measured.

Pete

 

[nigelmercier]

... The circuit at the panel is labelled "Instruments & Autopilot", fused at IIRC 15 amps ...

I don't recall the breaker size, but according to the manual:

Drive Unit / Circuit Breaker Size
Type 1 / 25A
Type 2 / 40A
Type 3 / 40A

I don't know what "Type 1" etc refers to, the manual is not clear.

 

[prv]

I don't recall the breaker size, but according to the manual:

Drive Unit / Circuit Breaker Size
Type 1 / 25A
Type 2 / 40A
Type 3 / 40A

I don't know what "Type 1" etc refers to, the manual is not clear.

As the column heading states, they refer to the drive unit. Makes sense since this is where nearly all the power goes.

I obviously didn't recall the 15 amps correctly, but I will have checked the manual when installing the circuit so there must be a 25amp fuse in there (I have a Type 1 drive).

Pete

 

[DipperToo]

As a point of interest, when I took delivery of my boat, the C80 was wired to supply power to the wind/depth/log. From time to time strange behavior from the instruments and Raymarine said that using the C80 to supply power was not a good idea as it was very limited in the power it could actually supply to the seatalk bus, and to disconnect the seatalk power line from the C80. I found out that the bus was actually powered from both ends with the S2 course computer at the other end). The issues I was having were down to when the course computer not switched on.

 

[nigelmercier]

As the column heading states, they refer to the drive unit...

Indeed, but I have no idea what drive unit I have, or how to find out.

 

[nigelmercier]

[UPDATE] I wrote something like this, with corrections:

... [Raymarine Type 300 Autopilot] has a permanent power feed (fed via a 25A independent breaker); I also have a separate switch that turns all the instruments on.

Given that the 300 is connected to the ST60 instruments via the SeaTalk bus, and is also permanently powered, how is it that I can turn the instruments off?

I've done some tests. The 25A feed draws 170mA with the instrument switch off, and does not change when I switch them on. However, the SeaTalk outputs on the 300 are not powered until I turn the switch on. The wiring on the 300 looks like this:

So now I'm confused again, I expected to see the SeaTalk power lead disconnected inside (the SeaTalk lead on the right has just been installed). There is a separate power lead to the cockpit, but why doesn't the 300 provide power?

 

[Caladh]

If you go "down below" to your autohelm drive unit you will see "Type 1" (if it is a type 1 unit) on a label on it. I had do this earlier
in the year to ascertain what I had.