Outback Inverter/Charger Low voltage cutoff point...

[MikeP]

This isn't a real problem but something to be aware of. Maybe everyone is aware of this but me; or maybe not....

If the shore power voltage is too low, the ac power supplied to the inverter/charger will not activate the pass-through and the charger will also not charge the batteries. You can adjust the voltage. Read on for the story.

We are currently docked at St Michael's museum marina in MD. Normally we do not stay at Marinas when cruising, preferring to anchor out but we have guests aboard who have a small dog that needs to be walked and it's a lot easier to walk down the Tide-Ride than it is to fire up the dink.

Anyway...

Last night I noticed that the AC LED on the Outback's remote control panel (the Mate) was flashing. I had never seen it flashing before, only steadily lit (AC present) or off (AC NOT present). I looked up the flashing led in the instructions and found that it meant that AC was present but not connected. I was very confused; if the unit sees that ac is present, why does it not automatically connect? I found no further explanation in the instructions for the Outback or the remote unit (the "Mate." (NOTE, this doesn't mean there isn't more explanation, just that I couldn't find it)

Essentially, what it meant operationally was that the circuits served by the pass-through on the inverter were not receiving shore power ac, the inverter and batteries were supplying the power, as they would be on the hook and the genny not running. All other circuits on the boat were normal and everything worked (Air cond, stove, lights, etc). Of course, since the inverter was not receiving ac, it was not charging the batts.

Did a bunch of trouble shooting to no effect, thinking that the inverter had failed in some way. One of the guests suggested I try the genny. I couldn't see any reason to do this but to humor him I did so. The Outback locked on to the power and immediately functioned as normal.

WHAT THE...???

After more trouble shooting I finally noticed that the genny voltage on the master elec panel showed 240VAC BUT the shore power voltage showed 200VAC.

I then checked a 120vac outlet on the boat and found only 106vac present on shore power.

Something finally popped into my head and I pulled up the menu on the Mate that includes the low voltage and high voltage cut off for the inverter ac input (which handles the pass through and the charging). TA DA! It was set at the default of 108VAC, 2 volts above the voltage being supplied to the outback. I entered 104 VAC into the Mate and the inverter locked on and functioned normally.

SO...modern charging/inverting units may have to be adjusted if the shore power being provided is not what it should be. Interestingly, the ancient LaMarche charger, which I still have in place but normally turned off worked just fine with the lower voltage since it is not a "smart" charger...

[REBrueckner]

Mike
great post, thanks.
As I never stop at other Marina's I have never had that problem nor was I aware that any units allowed selection of ac cutoff voltages...have to reread my FREEDOM inverter instructions and see what they say.
This is a potential reason not to connect ALL on board ac to an inverter unless the ac settings ARE adjustable as Mike described....

[Brian Degulis]

Low shore power is a problem in lots of marinas. Some places bring in 3 phase which is 208V on the high legs and 120V from high leg to neutral. The problem with this on our boats is the transformers. Our boats don't bring the shore power neutral on the boat. So what you get is 208V on the high side and then instead of 120V like the shore circuit you get 1/2 of the 208 so 104V. Ad some normal lose to that and your down under 100V. This will damage stuff like the fridge and Air Conditioning compressors.

Luckily for us most of the transformers Hat used can be set up with a rotary switch to boost the voltage when needed. There are several posts about this on here.

Brian

[sandspur1966]

I learned that lesson the same way Mike. Since many marinas save $$ playing the 3 phase game instead of providing true 220v power you will get below the 200v cutoff more often then not. (It hurts compressors and some electronics as well.)

The fix, as Brian said, is a simple re-wire of your OEM transformer to provide boost. Don't let anyone talk you into a new buck and boost transformer... the OEM hat unit lasts forever and works fine.

[REBrueckner]

"The fix, as Brian said, is a simple re-wire of your OEM transformer to provide boost"

How would one accomplish this??

[sandspur1966]

There is a wiring diagram available either through Hatteras or Roger Wetherington at Jarrett Bay that walks you through it.

Basically it involves swapping some leads on the transformer and adding a switch.

Mine is on the main power distribution panel in my wheel house and I have it labeled "boost" and "No Boost." If Im below 210 volts I hit the boost and start pulling about 6 amps or so.

I think there are several threads on HOF as well

[MicroKap]

I have those switches on my panel (have not checked the actual transformers), but when I tried to switch them to "Boost", it flipped the breakers all off and they wouldn't reset. My boat club had new docks and new electric put in last/this year and went with the 208v three-phase as described above probably because it was cheaper for the club and the electric company. I had bought a buck booster from Ward Electronics a few years ago, however, it costs me about 10% of my amps in the boosting process, along with the expense. At the time, I felt it was better than burning up another a/c compressor.

Can anyone lead me to the posts on switching the transformer so I don't have to have the buck booster sitting in my cockpit any longer?

[MikeP]

Later this morning at St Michaels a 120vac receptacle in the boat was down to 102v and the inverter went to the flashing mode again. But this time, knowing what the issue was, I ignored it.

Back at our marina and shore power connected I just now checked the same 120vac receptacle...120.5VAC and the inverter is perfectly happy!

[bobk]

MIke, I just joined the museum and planned to go there a few times this year. Do you know if all the recepticles are deerived from three phase? I've encountered a couple of places where one dock is and others are regular 240V.

Bob

[MikeP]

No I don't know about power for all the slips. It's the first time we ever actually berthed there. Normally when we go to St Michaels we anchor in the small harbor area right across from the lighthouse. It is a good deal pricewise to be a member - the slip cost us $94 for the night, including the admittedly marginal elec and, since they had no reservation needing that size slip for the next day, they told us we could ignore the noon checkout time.

The elec thing was interesting in that had we NOT had the outback inverter charger, I would never have known that there was a problem because initially it was the only thing VISIBLY affected by the low voltage. Everything else acted completely normal though, as has been pointed out, an extended stay might put a burden on components such as AC, fridge, etc.

But in the morning we noticed that the toaster "wires" wouldn't get red-hot and the result was decidedly closer to warm bread than toast. Also, the digital temp readout on the fridge showed 6 degrees in the freezer side and 34 in the fridge side; the settings are 0 and 34 so it was also affected by the low voltage. Back here it is at its normal 0/34 as it also stays on the genny or with the inverter.