[TG] [TG11] Fluxgate compass / course computer troubleshooting

[Tom - Raymarine - Moderator]

Hello Tony,

Quote:Are there functional differences between S2G and 150G and/or the different S2G "E" numbers?

T150G was the earlier name for S2G, and so is also probably running earlier software. An early T150G could be updated to the latest version of S2 software and then would be essentially indistinguishable (earlier units would have an older but not inferior version of the rate gyro) from an S2G, except that these units probably haven't had the upgrade because it was a somewhat difficult dealer-only upgrade, from a PC using a serial cable.

As far as different part numbers for S2s go: you would have system-pack part numbers and individual course-computer spare part numbers, and then there would be an S2 non-G and S2G part. If you can give me specific part numbers, I can tell you what they are.

Quote:The ACU-200 has a RF Ground connection that from what I can tell was not required on the S2G. Is it crucial that I connect the RF Ground on a new ACU-200 or is it likely that if I have not had interference issues with the S2G I should be OK with the ACU-200 not having this connected assuming I install at the same location?

Correct, the old S2-generation pilots didn't have an RF ground point - I assume the design simply used the supply negative for this purpose. On newer systems we separate RF ground and supply negative in order to allow a dedicated ground point which some vessels have. If you don't have a dedicated RF ground point the normal practice would be to connect the RF ground along with the supply negative - you should use the ground terminal on the ACU, but you can connect this along with the -ve power to make installation easier.

The ACU's installation manual says:
It is important that an effective RF ground is connected to the unit. The unit can be grounded by connecting the drain conductor (screen) to the vessel's RF ground point. On vessels without an RF ground system the drain conductor (screen)
should be connected directly to the negative battery terminal.

The dc power system should be either:
• Negative grounded, with the negative battery terminal connected to the vessel's ground; or
• Floating, with neither battery terminal connected to the vessel's ground.
If several items require grounding, they may first be connected to a single local point (e.g. within a switch panel), with this point connected via a single, appropriately-rated conductor, to the vessel’s common RF ground point.


Tom