Xantrex ProSine 2.0 behavior

[Microship]

HI...

My boat came with a ProSine 2.0 inverter/charger (2000 watt sinewave), and I was warned by the seller that it sometimes needs to be reset. Sure enough, in both recent Puget Sound windstorms, the loss of shore power put it into a state that requires manual intervention.

The pathological part of this, of course, is that it is sucking power the whole time. So when I arrive at the boat, days after it has gotten stupid, my expensive AGM battery bank is significantly depleted. All that's necessary is to turn the ProSine off and on again, then it immediately starts charging at a high rate.

Is this just a fluke with mine, or do they all do this? Obviously, this can kill off batteries in short order, and is a poor response to an interruption in shore power. I can work around it with a low-voltage monitor and a micro with a FET or two to take care of the switch-cycling, but it shouldn't be necessary to do that myself...

Cheers,
Steve

[Rick]

Would you please be more specific regarding the exact symptoms of the problem? What constitutes "manual intervention"? What is "gotten stupid"? Admittedly such scientific uiniversally standardised terms are lost on me.

[Microship]

Ah, sorry for the geeky vagueness. It goes into a mode after a power failure (with an error message on the LCD, which I forget), and just sits there slurping power from the battery bank until I physically cycle the power switch on the ProSine off and back on.

I suspect this is not normal behavior, and should probably send a note off to Xantrex tech support. At all other times, both inverting and charging, it appears to work perfectly.

Cheers,
Steve

[Rick]

I cannot yet surmise if it is normal or a problem. In "auto-invert" mode when a power failure occurs the charger mode ceases and the unit automatically enters into what can be referred to as an "autoinvert" mode. In the invertermode (either automatically generated or manually forced) that particular unit is not very efficient and draws on the order of 5 Amps or so which could be interpreted as "power sucking" or some other colloquial term. Indeed, compared to other brands this is a very inefficient inverter with no ac loads present in the "no-load" inverter-mode operation.

If the unit is not set up for when the input ac power is removed to invert yet merely to be in "standby" waiting for ac power to re-assert and then re-enter a charger mode then there should be very little battery current. Yes, I have observed several instances when the Pro-sine inverter/charger does not automatically re-assert a previously set "mode" of operation. The predominant cause is due to an instantaneous (or longer) dip in battery voltage below about (what I have measured regardless of specification) 10 Volts. When that happens I believe that the memory gets lost or reset by the processor. Yes, this model is marginal, in my opinion, in regards to a low voltage operation tolerance, yet it can be vastly degraded or helped by good wiring and battery low internal cell resistance values, not always realized just as might be expected.

Should this be your problem one help is to use large capacitance, low ESR (Equivalent series resistance) capacitors (tranlation: physically large and electrically large and relatively expensive yet GOOD) placed as physically close as possible across the input connections to the inverter/charger. 20,000 micro-Farads to one Farad rated at 25Volts. A low ESR would be on the order of 3 milli-Ohms and less than 10.

[Microship]

Wow, what a helpful and interesting response - thanks, Rick! I've only owned the boat for a few weeks, and haven't yet done the reverse-engineering that will be necessary to see what I really have on my hands from a systems perspective. I was not aware of the "auto-invert" mode, and will RTFM pronto.

I'll also stick a recording DVM on the front end and subject it to a forced power failure to see if a momentary glitch is responsible for triggering the problem. The big cap is a good idea.

Thanks again!
Steve

[Boracay]

My concern as a steel boat owner is that those auto inverted electrons might not be going into the ether but might be reinforcing some differential between the boat and the briny.

I have resolved to keep the electrical system on Boracay unearthed (relying on the leakage sensing devices of the marina, good repair and electrical isolation of the generator and the starter) but I am not happy about the compromise.

At sea I think that I will do the same if using a Honda generator.

Is this unwise?

[Rick]

Marine grade inverters have a neutral bonding relay that, in the invert mode, force the neutral into contact with the "green-wire" ground. Not ostensibly a problem until considering external potentials created by not having sufficient zincs or having an external fault caused by others.

One good solution is to use a galvanic isolator. In the case of USA type wiring AND an inverter/charger that has an internal ac transfer switch (utilized by the user) it is necessary to use TWO galvanic isolators: one located between the ac input from the shore to the inverter/charger transfer switch and another from the inverter/shore transfer output. I don't believe that the second one is addressed by ABYC in this case to minimise your problems when the neutral bonding relay is brought into play.

[Alan Wheeler]

Can a Galvanic Isolator be simply made Rick?? Do you have a simple circuit for one that you could share with us??? I don't like the idea of Transformer isolation. Heavy and expensive.

[Whimsical]

A Galvanic Isolator is simply 2 diodes in series with another 2 in series and reverse parralleled. Just use two of the big block type rectifiers and mount on a heatsink.

Mike

[Rick]

MIke is correct. Find a full-wave bridge rectifier module rated for about 200V or more and 30 Amps or more. they have a center hole to put a mounting screw and place against a heat sink like a hunk of aluminum. The higher the current rating the less heat sink you might need. Keep in mind that in case of a fault the diodes have to hold up long enough for a breaker to open.

They usually have the universal sine symbol for the two connections that you will use: one for the shore neutral and the other for the green-wire ground (doesn't matter which one is which). Use a short 10 GA wire to short out the other two terminals. The resulting topology gives you two diodes in series and "back-to-back" for either cycle of a fault waveform.

Yeah, ABYC wants to see a capacitor of the correct low impedance so that if a fault occurs you don't even measure 2V on the neutral wire but I feel that 2V is not likely to kill a kid in the event of a fault AND if a kid gets on the grounded pulpit with one leg in the salt water. But add one if you want to be "correct".

The two diodes will not conduct a significant amount of current at 1.3V of dc present which is less than the dc you will see from a zinc and, therefore, the anodic protection is held off of the neutral.

[David M]

I have a 3000 watt Prosine on board. I don't know if your does, but mine has error codes. Call the manufacturer with the error code and they can give you a better idea as to what is happening. I would do that first before I start messing round with other stuff. Mine requires that I reset the unit when the battery voltage drops below (I think) around 10 volts or so.

I would not assume you need a galvanic isolator until after calling the manufacturer.

[alanwesthagen]

I have had a Prosine 2.0 for six years. Actually I have had two. The first one gave up the ghost shortly after I installed it. Xantrex promptly replaced it and the new one has been nearly trouble-free ever since.

I do not leave the unit in invert mode. It charges the battery bank while the shore power handles any AC loads that I happen to have switched on. When power failed, the Prosine has always started up properly as soon as power was restored.
(My boat is moored on Puget Sound, too.)

The only situation that causes my Prosine to become catatonic is over-heating, which can occur when the charge going into my AGM house bank is more than 100 amps. The Prosine halts with an error indication and manual intervention is required to get it going again. While it is halted, however, it is not depleting the battery or consuming any significant amount of shore power.

[Microship]

Interesting, folks; thanks for the data points. Next time I'm on the boat (photos over here), I'll sit down with the Prosine manual and get to know it. Going into inverter mode certainly doesn't make any sense in my application... I'll report back when I know more.

By the way, I just bought the much-loved Outback MX60 maximum power point solar charge controller for the deployable PV array... I'll post details once that project is underway.

Cheers,
Steve

[Microship]

Reawakening this long-dormant thread to add a data point: the propensity of my Prosine 2.0 to enter a failure mode upon shore-power glitch events, creating the pathological condition described above, also has another and more subtly sinister component. At some point since the last time I went through setup, it decided I have a 200 amp-hour generic gel battery bank, instead of a 630 amp-hour AGM. This translates into lower setpoints, less thorough charging, and shortening of the AGM bank's life (according to AGM battery specs, anyway; I can't prove this).

Now that the bank is in fact on its last legs and getting long-in-the-tooth anyway, I'm replacing it... and at the same time installing the gorgeous new Outback FX2012. I'll post details in my blog when it's done. (Nomadness)

The new installation will address a problem introduced by whomever installed the Prosine... inadequate airflow. I had to limit charging rate to 50 amps to prevent overheating, since it was in a closed equipment cabinet with no convection.

Cheers,
Steve

[Barbara Harbin]

We have overheating mostly when in hot climates as in the Bahamas. We have a Northern Lights generator 6kw. We also have inadequate airflow in the tank room where unit was installed. We have to lift the floor boards to get bettter airflow when trying to charge batteries. Steve, could you provide info on limiting charging to 50 amps as we have 1000 amps of batteries and my husband says we need to charge at higher rate.
Barbara