Automatic Charging Relay

[grahamdouglass]

Last December I had my modified sinewave inverter charger replaced with a xantrex true sinewave. I also had my simple on/off start battery switch changed to a 1,2 and all switch for emergency combining and charging both while at the dock.

I have a 150 amp alternator and use a Victron FET isolator.

I have bought a ML-ACR 7620 so I can leave my Start battery fully isolated excepted in emergencies and charge both while at dock side. While under way my Alternator charges both house and start through the isolator.

Question.

I want to install my ACR with out using the manual override rocker switch that comes with the ACR. Since I have a combiner switch already I don't need another one.
Can I just connect the two positive cables to start and house bank and connect the ground wire form the rocker switch wire harness to my negative bus? And not connect any of the other wires to the rocker switch?
Also, the negative wire is really small, like 16awg what fuse are we looking at for that 2 amp? or 5 amp?

Also, what happens when you start your engine does the current drop on your start battery cause the ACR to combine? I noticed there is wiring for the positive start post or ignition switch in the rocker switch combiner.

 

[dhays]

Also, what happens when you start your engine does the current drop on your start battery cause the ACR to combine? I noticed there is wiring for the positive start post or ignition switch in the rocker switch combiner.

A significant voltage drop that lasts for a long enough (30sec?) time will cause the ACR to open. A big voltage drop that lasts for 10 seconds will cause the ACR to open as well unless the voltage is rising again.

Keep in mind that it is a charging voltage to the battery that causes the ACR to close to begin with. So if you disconnect from shore power and the voltage drops below 12.75v for 30 seconds (my numbers may be off) then the ACR will open. When you start the engine, the ACR will be open until the alternator spins up to supply a charging voltage again then the ACR will close, combining the batteries.

So in normal operation if you are starting the engine after being disconnected from your shore power, the ACR is open anyway.

 

[ofer]

additional info...

http://assets.bluesea.com/files/resources/instructions/980014350.pdf

 

[ofer]

BTW is there an ACR for a 32V system or ones that could be customized for the desired voltage?

 

[DDW]

I believe that ACR will combine automatically with just the ground wire, but you need a positive wire from the combine switch to force it to combine. Usually the fuse is in the positive, not the ground wire side. It is very low current so 2 amps will do - it is just to protect the wire. What did your original combiner rocker switch do? A rocker seems light weight for an emergency combine.

I did a similar install on my boat, it had a high current manual combiner switch, I repurposed it to force combine the ACR since is was already nicely mounted and labeled.

One peculiarity of some Blue Seas ACRs: when locked off with the manual toggle, and charging voltage is present, they will attempt to combine every 10 minutes making a loud "clack!". It will do this forever, does not combine because of the manual lockout, but tries again 10 minutes later. So I am changing my install to use the included two position rocker, one of which is force separate, and will presumable keep it from doing this.

 

[dhays]

One peculiarity of some Blue Seas ACRs: when locked off with the manual toggle, and charging voltage is present, they will attempt to combine every 10 minutes making a loud "clack!". It will do this forever, does not combine because of the manual lockout, but tries again 10 minutes later. So I am changing my install to use the included two position rocker, one of which is force separate, and will presumable keep it from doing this.

That is one thing about the BlueSeas ACR that I find annoying. OTOH, it is so reliable that I can live with it. Your solution would work well I imagine.

 

[CharlieJ]

I want to install my ACR with out using the manual override rocker switch that comes with the ACR. Since I have a combiner switch already I don't need another one.

The rocker switch is not a "manual override" switch. It is a remote actuating switch used to change the state of the 7620 from on to off or off to on. The yellow knob on top of the 7620 can be used to either change the state from on to off or off to on and can be used to lock out the 7620 so that if the remote rocker switch is activated, the 7620 will not change state.

The B- wire is part of the electronics' and the switch backlight circuit.

The way you are describing your planned installation, you are using about 10% of a fairly expensive piece of equipment's capability. I don't understand why you want to have two switches (1-2-both) and the 7620 in parallel with each other.

I installed ten of these on a 70' catamaran and have never experienced the "clunking" described up thread when they were locked out with the yellow knob. Strange.

 

[dhays]

I installed ten of these on a 70' catamaran and have never experienced the "clunking" described up thread when they were locked out with the yellow knob. Strange.

My boat is only 43’. The ACR is installed in the aft cockpit lazarrette against the same wall as the aft saloon wall. When sitting in the saloon, the “clunk” as the magnet engages is quite apparent. If the ACR is locked out using the yellow knob on the top, it will try to engage every 10 minutes there is a charge source on the house bank. The same “clunk” occurs when it makes the attempt.

The 7622 has the ability to have a remote switch installed, but it isn’t necessary. I have no need for the remote switch, but do find the lock out capability of the 7622 nice to have.

 

[Brooksie]

The short answer is yes you can install with just the two battery connections and a small ground wire. I bought one (Bloe Seas) when they first came on the market, installed it that way, and never looked back. Such a simple, elegant device, why complicate things.

 

[DDW]

I didn't notice it at first - probably attributed the noise to something else - once I noticed it I heard it all the time. It says it does this in the manual for the device, and it does. It needs to be locked out and charging voltage present on at least one side for this to happen.

I have a storage case where I want to lock it off for winter storage, don't want it clunking every 10 minutes for 6 months. I think, but not entirely sure, that the remote switch set to "separate" will accomplish that.

 

[rwidman]

BTW is there an ACR for a 32V system or ones that could be customized for the desired voltage?

I suggest contacting the manufacturers of the various ACRs and asking them directly.

 

[kchace]

I didn't notice it at first - probably attributed the noise to something else - once I noticed it I heard it all the time. It says it does this in the manual for the device, and it does. It needs to be locked out and charging voltage present on at least one side for this to happen.

I have a storage case where I want to lock it off for winter storage, don't want it clunking every 10 minutes for 6 months. I think, but not entirely sure, that the remote switch set to "separate" will accomplish that.

The best thing to do for winter storage is pull the ground wire so that the small amount of power it consumes is deactivated. This completely deactivates it so it wouldn’t clunk either.

Ken

 

[dhays]

The best thing to do for winter storage is pull the ground wire so that the small amount of power it consumes is deactivated. This completely deactivates it so it wouldn’t clunk either.



Ken

Good info Ken, thanks.

 

[Nepidae]

Automatic charging relay

First, Xantrex has a number of charges, charger/inverters with true sine wave performance, which 1 did you get?

Second, whose 150A alternator do you have? Does the alternator have a regulator and if so which 1? We have Balmar 125A alternators, with 614 regulators and duo-chargers to a centerfielder.

We have a similar ACR on our engine batts so that if our engine batts were to lose charge we can use our house to 'jump' a start batt. There is a switch that needs to be executed to provide this.

My suggestion, since you asked the question you asked, is to get a qualified electrician to perform the job. Since most boat fires seem to start in the electrical system and since you seem to not know what needs to be done, you might want to hire someone who does. I like to protect my boat as much as possible.

Keep us both safe. Hire the right guy.

 

[Nepidae]

P.S. We've wintered in Penetanguishene, ON and I didn't disconnect anything. I have a switch on the charger/inverter which I turned to off and turned everything else off as well. The boat went dark. We left her in Nov., I'll add here we have 2 banks, both AGM batts. House is 6-L16 6V batts and the Engine is 2-4D 12V batts.

Came back in May turned on the Balmar engine gauge, forget the reading, but that was the winter '18-'19 and still using the same batts. I've done this multiple times since we started the Loop in '16.

Works well for me and wet cell batts will require a different approach.