SI-ACR does not appear to be working

[Fred Koehlmann]

So after I had the main bank (4 x Interstate 6 volt batteries) installed, I added a spare 12 volt 27 group battery as bank 2. I also introduced a Blue Sea's SI-ACR 7610 between the two banks. For the first two to three weeks it looked like it was working just fine. My shore charger, EFOY trickle charger, and engine alternator all charger the main bank (go to the main bank bus), so the ACR should be changing bank 2 whenever it needs it and there is a charge on the main bank. At least this is how I understand it to work.

Just two weeks ago I finally upgraded my original shore charger from the Professional Mariner Flyback 20-3 to a new ProMariner ProNautic 1240P unit. I have to admit this unit is sweet and almost seems to charge the bank to full before we leave the boat Sunday nights. We disconnect the shore power when we are away during the week.

So lately the spare bank has been loosing power (its at about 60-75%), and I haven't been using it (I leave the switch on #1). I checked this last weekend and while the new changer was charging the main bank, I noticed that the green light on the ACR was not on. It should be on if it is working. Could the new charger have "killed" something in the ACR? There are no blown fuses in any of the lines. I thought the thing was suppose to be pretty solid. What cold have gone wrong? Has anyone heard of a defective unit?

[mainesail]

Make sure the SI relay has a good neg connection and be sure the start batt is wired into the ships neg bus, if you connected the SI's neg yo the start batt. 99.9% of the problems with these relays are wiring related..

Where are the + wires of the SI connected to?

What is the house bank voltage when you notice it not combined?

[Fred Koehlmann]

The negative is connected tot he negative bus where both banks, chargers, etc are connected to. One positive is connected directly to the positive on bank one and the other to the positive directly on bank two. The 1240P was charging at a maximum of 14.8 volts when I noticed it. Both banks are lead acid.

[Stu Jackson]

Frederick, did you employ this optional feature?

"Start Isolation allows temporary isolation of House loads from Engine circuit during engine cranking to protect sensitive electronics from sags and spikes"

[Fred Koehlmann]

Hi Stu,

No, I did not. There are two options the remote LED and the start isolation, and I did neither. I wanted to get the whole thing setup so we could get out on the water. I figured both were optional and not something that I didn't needed at the moment. My understanding is that the start isolation is not for the SI-ACR as much as for your on-board electronics. Since I make a habit to start the engine before having the crew switch the instruments on, I figured I was OK without it.

[Stu Jackson]

I agree, Fred, thanks for helping us with the diagnosis.

I've printed out the manual, will read it and get back to you.

Unless Maine Sail does first. 

[Ken Juul]

My first Blue Sea ACR failed during  the second season.  Can't remember the model number off the top of my head.  Called Blue Sea for troubleshooting advice.  They sent me a new one at no change and asked that I return the bad one so they could figure out why it failed.

[Stu Jackson]

Frederick,

I printed out and read the manual.  Seems simple enough.  If, as you said, you've checked the three fuses and the connections, and you've done the field diagnosis (checking the voltages at the two banks when you tun on the charger, and you've only sent the charger to the house bank, and not used two outputs), then the only thing I can think of is a defective relay.  ITWB, I'd call Blue Sea, like Ken did, and go from there.  Good luck.

Remember, as you've described your wiring setup, when you're charging, BOTH on the switch is what it's there for:  Backup!    Just turn back to 1 when charging from any source stops.  And the start bank only needs an occasional charge anyway, specially if you're using it as a reserve as you are.

[Fred Koehlmann]

Right you are Stu. We came up to the boat yesterday and I started up the charger. This time the ACR did light up, but then started to flash. Now whether it was a fast or slow flash is relative and only something you can judge if you've seen both (unless its rediculously obvious). But I my case neither flashing sequence made any sense. The start isolation was never hooked up, and neither batteries were low enough to cause a under voltage lock out. In the end I did what you mentioned. Flipped the switch to BOTH and charged both banks. By this morning everything was fully charged. I'll be taking the charge relay in for another one... just after we finish our vacation. We're off for two weeks with the kids on Georgian Bay.

During our vacation I'll be making use of our EFOY trickle charger, for quite charging, when we need it. I'm considering it an experiment, since we in the end determined that the effort to get solar panels on the boat before leaving was more effort and time than I had.  Will report on that later on.

Cheers Fred.