Outback wiring question

[carolinacoast]

I had our 3232 outback inverter wired to charge both port and starboard batt banks together, so I have in effect just one big bank. The PO put in a #2 generator that has its own AGM start battery, so we have a backup. the challenge I am having is that we are blowing the 50 amp fuse, presumably when I start the boat at the dock with the shore power running the charger. the guy I paid to wire it in says we are pulling the starting load through the #8 wire when the banks are a bit low and need to put in a starting solenoid. I am not a big poster since all of you experts have found and thoroughly solved any problem that I have yet run across. There don't seem to be any posts about adding things to this original design so I would appreciate some tips. I am headed to owners school next month for some needed education. Do I just install a Perko switch to have the outback primarily charge the port side and leave the starboard alone? Is he correct on the best way to easily keep the heavy amperage away from the #8 wire? thanks in advance.

mal hill

[MikeP]

I'm confused...

What 50A fuse are you talking about that is blowing, the big "shotgun shell" shore power fuse? What Number 8 wire are you referring to?

I have been using the 3232 with both banks combined for several years now and there is no issue at all re starting and the 3232 has nothing at all to do with starting. If the bank(s) have insufficient power to start the engines, there is no affect at all on the inverter OTHER than the charging circuit will be trying to charge the batts but that won't cause any breakers to trip/fuses to blow anywhere.

nothing related to shore power has anything to do with starting the engines/pulling too much current - that is all supplied by the batts.

It sounds to me like something has been wired incorrectly...

I don't suppose you have a wiring diagram of what he did?

[carolinacoast]

the shotgun fuse he replaced that got the charger to charge is in the starboard engine room on the aft bulkhead ( I thought that was the AC side). the outback is in the LeMarche location outboard of the hot water heater. what did not make any sense to me is the outback was powered the entire time, and he said the #8 wire is wired through that circuit. I'm not at the boat, and definitely don't have a wiring diagram. the way it was described the output from the charger goes through that fuse (makes no sense to me). I asked him to wire the positive side to both banks on the charger as Mike P and others have done on the HOF. obviously the draw and output of the outback is far less that the Lemarche, and I never had any problem other than water loss. I suspect incorrect wiring. does that shed any light?

[MikeP]

I can't really visualize what was actually done. All I can say is that something must be wired incorrectly. Since I'm not on the boat, I don't have the wiring diagram for the outback nor can I refer to how mine is set up - I'm very gunshy at trying to explain/recall it from memory...


Sorry I can't actually provide any useful suggestions.

Hmmm... is that fuse the starting system fuse?
Normally, a separate large DC fuse or breaker needs to be added along with a new battery cable to connect to the Outback DC terminals. I'm wondering if by using an existent fuse that is serving the starter system, it is being overloaded. That would make sense...

[carolinacoast]

that makes sense. sorry for having such vague info. He definitely did not add any additional wiring. I had my wife and our 2 kids under 3, and no opportunity to dig into the engine rooms. thanks. will advise tomorrow.

[Jim saco]

What I think your electrician is telling you is that your two banks are now one large bank and they are connected by a # 8 fused wire paralleled at your charger/inverter. If this is the case then when you try to start your mains your dragging amperage from the other bank threw the # 8 wire to the bank your starting your main with. That's if I'm reading into this correctly. You'll need to isolate one bank from the other or combine them when there put under a high load like spinning your mains up. He may be correct however he should have thought that out prior to your problem. Good thing you and your kids didn't get stuck somewhere other than the dock. Rather than putting in a parallel switch does your charger/inverter have two separate charging banks? Or both banks could be isolated when you start your mains via a relay. I'm not a fan of having only one bank. Anyway I could be totally wrong. Without a wiring diagram I can't be sure. Good luck to you let us know how you made out
Jim

[MikeP]

It is not wired as it should be. THere is no issue at all re the inverter and the combined banks if wired as described in the Outback wiring diagram. My combined banks system has been with the Outback for 2 years and there is absolutely no issue here. THe combined banks has NOTHING to do with this.

Although it's probably a bit sketchy to troubleshoot by long distance, I believe the problem is that the mechanic did not install a new pair of cables directly from the battery with the hot line through a breaker of the size required per the instructions for the inverter. It's all very clear in the instructions that a separate NEW feed from the batts to the inverter is required. (that's not an Outback thing, any inverter/charger would need such a circuit.

The mechanic may have assumed that since he was replacing the old batt charger, it would just connect the same way but it can't because it's NOT just a charger and the inverter takes power as well if it's turned on. So it makes perfect sense to me that as connected, the starter circuit fuse cannot supply sufficient current for starting AND inverting and it can't be expected to do so. NOTHING should be connected to a start circuit except the starter/associated relays.

I suspect that if you turn the inverter off, the problem will disappear but that's not the answer. The answer is to wire it as per the outback instruction manual.

[carolinacoast]

thanks guys and mike P in particular. very helpful, and will advise progress. thanks to all.

[MikeP]

Just had another thought...

You said the Outback was wired to charge both banks so now you have combined banks. The banks should be combined together first with sufficient sized cable, irrespective of the Outback just as if it was not there and you had decided to combine the banks. After the banks are combined, the outback is connected to either set of batteries that used to be one of the banks. Since the banks are combined, the Outback will draw power for inverting from all batts and charge all batts in the (now) single large bank.

I'm thinking that maybe the Outback has been wired so that IT is performing as the bank combiner and that just won't work.

What should happen is that the port and Star batt banks are combined (in Parallel) with a sufficiently large cable - the same size cable that provides starting power. I don't recall what size that is. When I paralled mine, I installed a battery switch so I could, if I ever wanted to, flip the switch and decombine the banks so they could return to OEM configuration.

If I turn the battery switch to "off" my banks are now back to oem Hatt BUT the inverter will now be functioning from and charging only one battery bank.

Since combining them I have never decombined the banks.

Sorry for just tossing out ideas without anything to really reference them to but the above just occurred to me as another possibility.

[REBrueckner]

Carolina:

Next time you are at the boat, check the voltage at the 50 amp fuse (from there to ground, a the negative of a battery or to the engine) in question....

Others here with your arrangement may be able to figure it out but I cannot even tell if the 50amp fuse you reference is 120volt ac or 32v dc.....In other words, does the fuse supply ac power to the charger (from an electrical panel) or is it in the dc output side between the charger and batteries???

Mike: So these chargers do NOT have isolation diodes within the charger.....is that why these "combine" batteries whether the charger is on or off?? That would explain why Outback wants heavy cables between battery banks...so that heavy starting currents are not passed thru the normally lighter charge wires....

With isolation diodes, as in say Statpower 40 chargers, isolation diodes prevent such feedback between banks via charging wires.