+- Tiara Yacht Owners Forum (https://www.tiaraownersclub.com/forum)
+-- Forum: Tiara Yachts Discussion Forum (https://www.tiaraownersclub.com/forum/forumdisplay.php?fid=6)
+--- Forum: Electronics & Navigation (https://www.tiaraownersclub.com/forum/forumdisplay.php?fid=28)
+--- Thread: Installing RF ground for new Garmin radar. autopilot, etc (/showthread.php?tid=6184)
Installing RF ground for new Garmin radar. autopilot, etc - Fuzzdr - 07-17-2019
Hello All; I have a Tiara 4000 Express Cruiser /97. I had a local marina swap out my Raymarine electronics for Garmin equivalents. I am having various problems most notably with the autopilot and open array radar. As the installer has not been helpful, I want to check things out myself. starting with the new chart plotter and radar. I did install similar Garmin units on another boat 9 years ago and that has gone well. For starters, I would like to know a practical way to install the RF ground wire between the radar voltage converter and RF ground. I cannot remember if I had installed a RF ground plate on the other boat or if I used something else? The rest of the wiring seems be very straightforward. When it comes to grounding AC, DC, RF, and Lightning return circuits things can get very complicated with isolation devices, capacitors, etc. I am not looking to install a system that would make a top marine electrical engineer proud. I just want to do what is safe and practical.
Re; the autopilot problem, I seems like my unit was not calibrated properly or at all. I was dismayed to find that the little model of my boat was not moving ahead with me on the chart plotter display, but backward to where I had come from. It sounds humorous but in reality it is not. I understand that this can happen when heading sensors (in autopilots) or when electronic compasses have not been properly calibrated. This seems to be my problem and hopefully a re-calibration of the autopilot will remedy the situation.
Any assistance or comments will be appreciated.
Fuzzdr
RE: Installing RF ground for new Garmin radar. autopilot, etc - jclark003 - 07-17-2019
your RF ground (or drain wire) typically is connected to a sea water ground plate. So some source that has direct metal contact with sea water.
Chartplotter issue sounds a little strange. So your ships icon moves backwards? So if you are heading North the icon moves South on the chartplotter, therefore having improper reference to position?
The position and movement on your chart plotter is usually a reference to the boats position (gps) and heading is in reference to where your ship is pointing. Is it possible your chart plotter is in North up mode and you are heading south? then your ships icon and movement will be oriented downward on the chartplotter.
Basic check of heading sensor is to compare it to your compass heading. If close then it is probably not installed backwards. If you want to calibrate your heading sensor check your Garmin installation manual for how to enter the initial setup/sea trial menu. There should be a calibration option. Most have you drive the boat in circles for a couple of minutes.
RE: Installing RF ground for new Garmin radar. autopilot, etc - Fuzzdr - 07-18-2019
Thanks to Captain J Clark for his enlightened comments and his interest in my situation. I boat in the fresh waters of Georgian Bay. I wonder if this makes a difference to the RF ground source? I am not sure if my chart plotter was set for North Up mode or not- will check on that. When I first noticed the boat going backwards on the display, I was actually travelling some flavour of east. This continued even after I had turned north and then westward and then north again. Early on I could see short glimpses of land even through the rain and poor visibility. I knew exactly where I was at that point even though I had lost my gps fix and had no working radar.
I think that after that I must have started to travel in circles inadvertently. Eventually our gps fix returned; it showed our position to be far south and west of our intended route! A circle course most probably took us there and it seems simultaneously calibrated the heading sensor of the autopilot which had been in standby mode. After the gps fix returned, everything improved and we were able to reach our destination without incident. Since then we have not had the opportunity to do a sea trial to determine what is working and what is not. That sea trial has top priority now.
Thanks again Captain J Clark. Please feel free to comment further as you see fit.
Fuzzdr
RE: Installing RF ground for new Garmin radar. autopilot, etc - jclark003 - 07-18-2019
Ok that makes more sense now. The gps tells your chartplotter where you are, your course over ground (cog), speed, etc. without a gps fix your chartplotter is lost. It's actually a little surprising your boat icon and chart information moved at all.
Heading data comes from the heading sensor and is primarily used by the autopilot to steer. The autopilot also uses gps data such as cog and speed to adjust for cross track error, etc. additionally the heading sensor usually gets magnetic deviation data from the gps which corrects heading Based on position.
What does his all mean? If you have bad or no gps data you are much better off with paper charts.
If your electronics installation is relatively new and you are seeing funny things happen like sensors dropping offline inadvertently you may have issues on your network. NMEA2000 networks have very specific power requirements especially on the ground and shield side. A very high percentage of electronics installation issues come from power and cable issues.
Your chartplotter installation manual should have a section on network installation and troubleshooting. That is usually a good place to start. Maretron.com also has some good data to help understand how these networks function and where to identify issues.
Good luck