Shore power not working 300 Marlin

[Angler Management]

'07 300 Marlin, new to me last May.

Shore power stopped feeding my boat about a month ago at an outlying marina. Now back at my home marina and have confirmed it is not the shore power nor the cord, but my boat that isn't allowing the juice to flow.

The genny provides juice to my circuit breaker panel and everything runs fine, AC unit, outlets, microwave, etc.... Once while testing the cord I was able to get the "reverse polarity" red light to go on in the panel, but usually no light or power at all. Again, shore side power works and my cord works fine as confirmed by a friends boat in the marina.

I can not find the charger....? Thinking maybe there's a bus bar input near this area that might be shot, or an inline fuse on the shore power inlet. HELP?!?! Don't want to burn my boat to the waterline, been there... done that...!

Randy :doh

 

[journeyman]

There should be a 30Amp Main breaker up under the gunnel near the shore power inlet. Tripped???

 

[Meanwhile]

I'm interested in this topic just to better understand my own boat.

For shore power, does it make a difference whether I use the top or bottom plug in for a 30 amp connection? Have you tried both?

 

[journeyman]

I'm interested in this topic just to better understand my own boat.

For shore power, does it make a difference whether I use the top or bottom plug in for a 30 amp connection? Have you tried both?

If you have 2 shore power inlets, you probably have a 50 amp panel. Each plug will/should power only 1/2 the panel. Using a Y adapter to power from a 30amp source will limit the boat's draw to 30 amps. If you have 2 inlets, you need either power from 2-30amp sources (separate cords) or power from 1-50amp source and a Y adapter at the boat. And we're only talking 125 VAC here.

I doubt Angler Management has 2 inlets on his Marlin although it's possible. He stated it stopped working while at another marina. possibly a surge or a polarity issue caused his main breaker to trip.

 

[Angler Management]

I cannot WAIT to go check under the funnel for this fuse/breaker. Wouldn't that be heaven!

I believe my second inlet in this area is for TV/phone/cable. I haven't lifted the cover in 9 months and will do so ASAP and report back.

However, still curious about the location of the charger? Is it under the cockpit sink/ behind the tackle locker?

 

[journeyman]

I believe my second inlet in this area is for TV/phone/cable. I haven't lifted the cover in 9 months and will do so ASAP and report back.

It is.

However, still curious about the location of the charger? Is it under the cockpit sink/ behind the tackle locker?

If you're talking about the battery charger, mine is mounted next to the Generator.

 

[Tuna Man]

I agree with Journeyman, most likely the breaker tripped below the starboard gunwale (near the rod holder nearest the transom).

Our battery charger is behind the aft bench seat, mounted vertically on your right after you open the access door.

 

[Fishtales]

I believe it is an AC line conditioner under the gunwhale starboard side and it does have a breaker. I had mine pop once when there was voltage fluctuations at the marina (others had it as well).

 

[journeyman]

watch this Grady White video, it shows the breaker (it's on a 330, but same location)...


https://www.youtube.com/watch?v=c0kgpRXIkPw

 

[DennisG01]

If you take a look in your manual, it will give you the locations of the items you're looking for. The 30A breaker is right near the shore power inlet on the starboard side (this has always been the case for any boat I have ever worked on, not just Grady). The other "thing" near the breaker is your galvanic isolator. And, yes, the "second" inlet looking thing is usually tv/phone. Your battery charger is back by the batteries on the port side. It's usually pretty easy to find the charger as it's often connected directly to the battery (look for 10-ish gauge red wires and follow them). Sometimes a charger is connected through a battery switch, but given the proximity of your charger to the battery banks, it's likely connected directly.

 

[Angler Management]

Ok, back on the grid. Breaker tripped under the gunwale, and charger located. Gives me a better idea about the run from shore to batteries via charger. Thanks so much

 

[raefordbrown]

Great discussion, but my problem is similar, but apparently it isn't the circuit breaker. I have a reversed polarity light that's lit up. Same boat, same slip, same cable. So, I checked the 120 volt connector at the end of the shore power cable. It was good.
I pulled the panel cover off, found the 10 guage cable coming in and checked it there, and there was no voltage. I disconnected the shore power cable on the boat, took the shore power connector loose from the boat, verified all wires were connected, reconnected the power cable, made sure the 30 am circuit breaker wasn't tripped, took another reading inside the box but used the black (hot) wire and the ground bus...it had 120 volts.
I then dissconnted the power cable, ran a wire from the neutral white wire inside the panel to the back of the boat, an put an ohm meter across across the white wire at the connector and the "jumper" wire I ran...and it "appears" the white wire is not connecting. My question, since I don't know the workings of the galvanic isolator, is it possible that it has suddenly gone bad? I cannot, for the life of me, believe the white wire, which is enclosed in the outer jacket of what appears to be stranded UF (underground feeder) could have corroded and come apart.
Any thoughts?

 

[wspitler]

A galvanic isolator is simply a transformer that prevents direct current from flowing from the dock to the vessels electrical system. Your boat believes, maybe correctly, that there is reverse polarity and will not let power onto the boat. The system that checks that in your panel is pretty reliable, start by making sure something upstream on the shore did not change polarity. There are simple plug-in devices that can test that for you in the shore based circuit. I can’t really follow your troubleshooting steps, but I would start by checking the voltage and polarity at the shore power end of the circuit.

 

[kirk a]

Very possible the plug on the boat needs to be replaced. Mine was replaced a couple years ago, after similar behavior. Turned out it was smoked inside. Once replaced, all was well again.

 

[Beyond A Wake]

Related but not quite the same. I had a wellcraft where it turned out one outlet in the cabin had been reverse wired from the factory. That is after the panel so no polarity issue and it did not happen over night.
In you case I would trace each cable from the back of the boat and see where it breaks. Didn't see how old your boat is but things that happen over night are usually corrosion or bad connection related. If a ground bonding green wire and the "white " wire are mixed that is not supposed to be the case And is a problem.

Fix it before a disaster happens.

H

 

[raefordbrown]

Thanks. I have a LOT of experience wiring homes and commercial buildings over the years. I have double checked the wiring at the plug on shore. Everything works great all the way to the back side of the plug mounted on the boat. I understand the concept of the galvanic isolator, and that is the ONLY thing after the circuit breaker and the panel that is suspicious.
It's also likely to be an original on my 1998 Marlin.
All AC breakers except the main breaker are turned off, and the reverse polarity is still lit.
There is no voltage across the hot black wire and the neutral white wire, but there is voltage across the black wire and the ground (green) wire in the panel.
Even as recently as 2013, old gavanic isolatoers were being changed out for ones that meet newer standards of the ABYC.
In this area, we've had a lot of lightning lately, including the day that my shorepower started acting up.

 

[raefordbrown]

Here's the latest. From the shore power outlet input, a 10-2 w/ground cable runs to a box with a circuit breaker. The difference between the Grady and house wiring for AC is intereesting and upon analysis, totally understandable. My issue was that the HOT black wire was connected all the way to the AC panel on the boat, but the NEUTRAL white wire had no connectivity. This produced a REVERSED POLARITY fault at the panel.
Turns out, the circuit breaker under the starboard gunwale is not a SINGLE pole breaker, it is a DOUBLE pole breaker, with both the hot and neutral wires running through the breaker.
The neutral side of that breaker was defective.
Double fuses are often used in DC connections, especially for high powered DC supplied radios, and even some Marine VHF radios.
In the AC supply side, it's a safety precaution, as boaters traveling from marina to marina may encounter "unusual" connections on the shore power supply.
Good for Grady White. Smart move, even back in 1998 for my Marlin 300.
Information for you just in case things aren't acting as you thought they should.

 

[seasick]

Interesting finding. Good to know.