Comnav CT 3 Controller with Furuno Nav Pilot 300.

[SDTugs]

Good day,

I’m trying to reimagine my autopilot system. What I ended up with was a Nav Pilot 300 and a Comnav CT4 motor controller to my vintage wood freeman 531 pump unit being driven by a 521a pump.

What I have run into is during the rudder test portion of the set up the pilot swing at the rudder back and forth at various angles and speeds. Once it’s gets to the starboard rudder limit it keeps going until the pump dead heads and blows the fuse on the Comnav CT3.

Has anyone run into this problem, or had any experience with a Furuno NavPilot 300 and a Comnav controller.

Thank you.

 

[twistedtree]

Can you sketch up exactly how you have the Navpilot and CT4 wired together? I see the CT4 expects a +5V input. Where is that coming from? I'm quite familiar with the NavPilot 700, and hopefully that translates to the NP 300.

In the setup process, the pilot asks you to turn the rudder fully to port and tell it when it's there. Then the same for full to stbd. That tells it where the limits are. Did you go through that process?

 

[twistedtree]

Actually, it looks like the Navpilot 300 is only compatible with reversing pumps, not with solenoid pumps. I think you need the Navpilot 700. Or you will need to create some electrical interface between the reversing voltage output from the NP300 to control AC solenoids.

 

[SDTugs]

I don’t have a sketch available, but am willing to tell you about it.

CT3 and NP300 take power from a 30a 12v breaker. The split at a bus bar. CT3 takes power from the bus bar to the positive and negative terminals on the CT3. The NP300 feeds the two signal poles on the CT3, the pump runs off the 3 split field wires on CT3.

The wiring seems very simple and hard to mess up.

The only thing I can figure is the 300 doesn’t send a start / stop signal. It just reverses polarity.

Not exactly sure where to go from here.

 

[SDTugs]

How would a person create electrical interference?

 

[ofer]

since the np300 does not have a rudder indicator it counts time from the two rudder limits. i dont have the answer although i believe that the time from port to starboard may vary in your situation. once the limit is reached and the pilot continues to steer it will blow a fuse. i believe you can add an RI on that pilot.

 

[SDTugs]

since the np300 does not have a rudder indicator it counts time from the two rudder limits. i dont have the answer although i believe that the time from port to starboard may vary in your situation. once the limit is reached and the pilot continues to steer it will blow a fuse. i believe you can add an RI on that pilot.

I did leave that out on the original post. The NP300 is connected to a FAP-6112 RRU.

 

[twistedtree]

So it's a CT3 and not a CT4? I can't find a manual for a CT3 so can't tell what it does, or what it expects for a control signal.

 

[SDTugs]

Here’s what I got. Doesn’t offer much.

 

[twistedtree]

It looks like the NavPilot 300 only supports a two wire reversing motor, the CT3 expected on/off solenoid input signals, and the pump is a split field reversing motor that I know nothing about.

Your simplest and most economical solution might be to replace the steering pump with a conventional reversing pump in place of the current pump and CT3.