SeaTalkNG power with ACU-400 - Best Practices

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Keith,

General comment regarding power: When considering power circuits for a vessel, consideration should be given to how the equipment within the system will be used and maintain the greatest level of system functionality in the event of a catastrophic failure of any single piece of equipment. Hence, it is considered a best practice to NOT power the SeaTalkng backbone featuring critical devices (ex. Raystar 130 GPS Sensor, etc.) from an autopilot ACU/course computer, as a catastrophic failure of the autopilot may prevent the autopilot ACU/course computer from supplying power to these system critical devices.

Q1. ...where he listed (among other things) ST70 instruments and the ST-STNG converter. But when using the converter then any ST60 instruments (and other classic SeaTalk(1) devices) are also getting power from the bus. Can they also be "switched" with the power to that bus? Will they behave the same viz power buttons as ST70 instruments? Or do they need to be powered up and down separately?
A1. ST60 instruments will be powered ON whenever power is present within the SeaTalk bus. As the ST60 instruments will be powered via the SeaTalkng backbone via a SeaTalk to SeaTalkng Converter(s), switching power ON to the power circuit supplying the SeaTalkng backbone will cause the ST60 instruments return to the ON power state.

Q2. My particular installation (see signature) has an ACU-400 which powers the STNG bus so the ACU and bus (with P70R, et cetera) are on one breaker. What are the best practices for turning off the AP power?
A2. Switching OFF the autopilot control head will not switch off power to the ACU or any SeaTalkng component other than the autopilot control head itself. The best practice for shutting down the autopilot is to switch OFF the power circuit supplying the ACU.

Q3. ideally, I'd like to just leave the AP - and STNG bus - powered up all the time (95% at the dock on reliable power). So...is leaving the AP system (and STNG network) on 24x7 a good practice? Or are there some discrete components in the Raymarine gear in my signature - like capacitors - with a finite life, even if that life is in years?
A3. Raymarine neither publishes mean time between failure nor expected life data for its products. The bottom line is that product life will typically be maximized by not power/switching the product OFF when it is not in use.