automatic charge relay

[fallard]

Looking for verification of ACR wiring in my recently-acquired 2019 R-27. The 2 ACRs in the port cockpit locker have a common wire that is routed to a negative terminal of the ganged house batteries, but it is not connected. The Blue Sea site indicated that this wire might be the connection to the "negative bus bar", to which the battery negatives would be connected, according to the R-19 Owners Manual. It looks like I should just connect it to the battery negative. (The previous owner apparently replaced the batteries within the past year, so it may be an oversight).

 

[Lake Effect]

Did you find the answer? Bringing this to the front.

 

[fallard]

Did you find the answer? Bringing this to the front.

I did not get a reply to my post, so I did connect the common wire from the 2 ACRs to the negative terminal of the ganged house batteries (which I understood was connected to the "negative bus bar, per the R27 owners manual wiring diagram.) Previously, I was uncomfortable with the voltage readings on the house batteries, but the battery voltages now look reasonable. I believe the problem is solved, but being new to the boat, was looking for confirmation of my assessment.

 

[Submariner]

Looking for verification of ACR wiring in my recently-acquired 2019 R-27. The 2 ACRs in the port cockpit locker have a common wire that is routed to a negative terminal of the ganged house batteries, but it is not connected. The Blue Sea site indicated that this wire might be the connection to the "negative bus bar", to which the battery negatives would be connected, according to the R-19 Owners Manual. It looks like I should just connect it to the battery negative. (The previous owner apparently replaced the batteries within the past year, so it may be an oversight).

The ACR sits between two battery banks on the positive wire. Engine and House, House and Thruster, for example. Being a 2019, yours probably are engine to Hosue, and engine to thruster. Because the ACR bridges the positive side only, and it needs a voltage reading to function, that's the yellow wire (needed to complete the electrical circuit to take a voltage reading).

The ACR's are just automatic parallel switches. When they see a charge voltage (engine running, solar charging, or the battery charger is turned on), voltage will go up to 13+ volts. The ACR's will see that higher voltage and will close, paralleling the battery banks together. When the charge voltage goes away (voltage drops to less than 13 volts), the ACR will sense that, and will open/isolate the battery banks.

If the yellow wire is disconnected (easy to knock off, if you store equipment in the port lazarette), then the ACR will never close/parellal the banks together. This means you won't get any engine charging of the house or thruster bank when underway.

This is a great video that talks all about the electrical system and how it works on your boat. I talk specifically all about the ACR's at timestamp 19:15.

Electrical Overview of a Ranger Tug R27-OB

 

[Lake Effect]

Thank you!

 

[fallard]

Thank you!

The ACR sits between two battery banks on the positive wire. Engine and House, House and Thruster, for example. Being a 2019, yours probably are engine to Hosue, and engine to thruster. Because the ACR bridges the positive side only, and it needs a voltage reading to function, that's the yellow wire (needed to complete the electrical circuit to take a voltage reading).

The ACR's are just automatic parallel switches. When they see a charge voltage (engine running, solar charging, or the battery charger is turned on), voltage will go up to 13+ volts. The ACR's will see that higher voltage and will close, paralleling the battery banks together. When the charge voltage goes away (voltage drops to less than 13 volts), the ACR will sense that, and will open/isolate the battery banks.

If the yellow wire is disconnected (easy to knock off, if you store equipment in the port lazarette), then the ACR will never close/parellal the banks together. This means you won't get any engine charging of the house or thruster bank when underway.

This is a great video that talks all about the electrical system and how it works on your boat. I talk specifically all about the ACR's at timestamp 19:15.

Electrical Overview of a Ranger Tug R27-OB

Thanks for the video.