ACR priority

[PLBart]

2020 R-27OB Is there a priority between the two ACR's, engine to house versus engine to thruster?

 

[Submariner]

2020 R-27OB Is there a priority between the two ACR's, engine to house versus engine to thruster?

The manual for the R27-OB shows there are two ACR's installed as follows:
House <--- ACR ---> Engine <--- ACR ---> Thruster

With this configurations when the engine is running, both ACR's see that charging voltage and thus, both ACR's should close and charge both the house and thruster battery with the same priority. When solar is charging, it'll charge the house bank causing the engine to House ACR to close. With the engine battery being charged via ACR from the house, the Engine to Thruster ACR will sense that voltage and will close allowing the solar to charge the thruster battery via the engine battery.

However, my boat was not wired that way from the factory. I don't know why my 2021 R27-OB was wired differently. I know I'm also not the only 2021 R27-OB wired this way.
Engine <--- ACR ---> House <--- ACR ---> Thruster

With this configuration, when the engine is running, the Engine to House ACR will close allowing the engine to charge the house battery bank. When the house bank is being charged the House to Thruster ACR will sense that charging voltage and will close, allowing the thruster to get a charge from the engine. This puts the thruster 2 hops away from the engine charging as the charge must flow through the house battery bank. But, this also puts solar equal distances away from the engine and thruster banks. i.e. when solar is charging, each ACR will sense that, will close, allowing solar to easily charge all three banks.

All three battery banks get charged when the engine is running with either configuration. But it does change the priority, as you had asked.

 

[PLBart]

Thanks, that is what I was gathering from the diagrams but was not positive. Interesting the new configuration in 2021.