Shore Power Electrical Gremlins

[rjengelhart]

Ahoy Shipmates,

Need some help. Hull #464, which I've owned for almost a year seems to have developed electrical gremlins.

Here's the setup

--Four Optima AGM 75AH batteries; 1125MCA, 900CCA, 155Reserve Capacity. All dated 5/12
--Duracell Ultra Group 24, 1000CA, 800 CCA
--Xantrex Freedom Marine 25 Inverter/Charger

Can't keep shore power energized; either the shore house circuit breaker trips or the shore GFCI trips. This happens whether the AC shore power cord or (separately) the house power cord are plugged into the boat; each has a separate power cord. I tried each on a different circuit and the GFCI tripped.

This started about a month ago. I've tried every combination of power cords, various vessel switches in different positions, all to no avail. The house bank will light up the inverter for about 5-10 seconds, then the shore circuit breaker or GFCI trip. Interestingly, powering up the AC (w house power cord disconnected) will also trip the breaker or GFCI. Is there a common link btwn these two circuits (and I don't really know how the inverter was installed?...didn't notice one on the schematic, and it sure has me baffled.

Had to jump start Andiamo the other day...starting battery dead, another issue...that starting battery connected to house bank. Anyway, engine and instruments ran OK, but inverter did not power up...hhmmm. Bad inverter?

If the inverter installation somehow included the AC circuit, would this explain each circuit (AC & house) trip the shore circuit breaker/GFCI?

Any ideas, past experiences w this type of issue?

Thanks to all in advance.

Other than this issue, Andiamo is a pleasure to sail. Sea kindly, spry, dry.

vr
Bob Engelhart
SV Andiamo
#464
Punta Gorda, FL

[scott.monroe]

Good morning Bob,

Love those gremlins!!
Couple of questions for you, when you refer to the shore house circuit breaker are you referring to the main breaker in the lazaratte, and the GFCI is this located on the marina pedestal or one of the GFCI on board? You also mentioned you tried both the AC (air conditioner) shore power cord and house power cord. Does this mean you swapped the power cords and the house circuit kept tripping? Note the Air Conditioning circuit and house circuit should be 100% isolated from each other, shy of the ground. Both circuits aren't tripping are they? Lastly does this tripping occur when you have loads turned on on the boat, i.e. breakers are turned on on the distribution panel. Do you have the same results if everything is off on board?

Anyway, here is an image from Xantrex that might help explain the wiring (assuming the installer followed the instructions). Shore power goes through the main breaker (located in lazarette) then directly to the inverter/charger which when plugged in to shore power acts as a battery charger and a pass through for shore power to your main distribution panel. When shore power isn't plugged in then the inverter/charger switches to inverting mode, pulling power from batteries to generate alternating current and sends alternating current to your distribution panel. Again your air conditioning circuit should be totally separate.

It could be that your inverter/charger has taken a dirt nap. If internal circuitry has shorted in the unit it would most certainly behave the way you describe. Inverter/chargers are not serviceable so replacement is only option.

One more thing, your house bank of batteries is either on their way out or cooked. 8 years on batteries is probably outside their usefulness, you may want to look to replace them.

Take care,
Scott

[Henry2000boats]

Had something like this happen and it turned out to be a bum power chord. You probably have already looked at both prong and female side of the power chord to determine if they look “burned” a bit. They do go bad. These issues can be very perplexing; I’d get a reliable source recommendation on a marine electrician.Good luck!

[rjengelhart]

Thanks to all who responded and helped. All is good now...here's a summary.

--Had my shore power cord plugged into a 15amp circuit...that's why it kept tripping;
--Realized I did have a 30amp outlet at my dock, but had forgotten (it's adjacent to my lift controls and didn't check it out);
--Once I had that squared away power to the boat was OK...could run house & AC simultaneously;
--Never having had an invert, I was unfamiliar w its operation, display and various switches and lights. turns out I have a switch that will isolate the inverter/charger...a safety issue;
--Had a marine electronics fellow square me away on proper operation (and a load test of the house bank and starting battery; < optimum, but OK.)

Anyway, all is well and I'm far more confident about my I/C understanding.

vr
Bob Engelhart
SV Andiamo
#464