Question About Alternating Current Side

[DennisM]

Maybe some kind, experienced person can answer what might turn out to be a dumb question. Yesterday I connected to shore power with a cord that didn't work. I threw the circuit breaker, and the AC light did not come on. I then went and got a patch consisting of a marine 30-amp connector to standard 110v connector, back to marine and then into my shore power cord.

This lit my AC light okay, but when I threw my battery charger breaker several times, I either got no light indication or a brief flicker on the reverse polarity light. When I threw my water heater breaker, nothing happened. The AC outlets switch seemed to work fine, though, as did the "spare," whatever that is.

Obviously, what I was hoping to do was charge my batteries using shore power. This has worked fine in the past with the same source and the same patch arrangement. It didn't work this time. Anybody got a clue? Did I damage my battery charger by using the bad cord first? I'm mystified.

[S/V_Surya]

Although your discription looks good its time to get a voltmeter and start checking voltage and polarity. I doubt you damaged your battery charger. It sounds like a bad cable. Did marina change anything do any work on electrical systems?

[DennisM]

Thank you, Surya's skipper. I'll find out about the electrical work, and I'll finally purchase the voltmeter I've been putting off. I'm relieved that you believe I probably didn't damage my battery charger. Thanks again.

[David M]

Good choice Dennis, getting a quality digital multimeter is a where I would start. You can't do a proper diagnosis without one. You do not want to be guessing at this risking damaging equipment.

With the boat unplugged, I would start at the shore power outlet checking the polarity and voltage. If that checks out, then put the shore power outlet under a load, such as plugging in a space heater, and see if the voltage holds. There should not be more than about a 5% drop with say a 12 amp space heater. You will need a 30 amp to 15 amp adapter which are much less expensive at a good hardware store than at places like West Marine.

Then plug in your boat with all the AC loads off and gradually work your way to your boats AC panel. If that checks out then put each of your AC loads online one at a time testing each load individually. Check again for polarity and a voltage drop.

Also get yourself one of those 15 amp outlet polarity testers at the hardware store which could come in handy for future use as well.

Let us know what you find.

[DennisM]

Thank you for the details and procedure, David. I'll let you know what I find out.

[skipmac]

Hi Dennis,

David's advise is right on. One thing to keep in mind as you follow his procedures is that even with a very bad connection you may see voltage in the system with no load (like showing only the AC light on the electric panel) but as soon as you add any real load the voltage can disappear or at least drop significantly. That's the logic behind adding AC loads a step at a time to the system.

Skip

[DennisM]

Thanks, Skip. I believe what you're describing is exactly what I'm seeing. I didn't know about that phenomenon. I'm definitely going to buy a meter...and a polarity tester.

[btrayfors]

Dennis,

Check the shore cord connections carefully. If they show ANY sign of blackening around any of the three connecting pins, they will need to be REPLACED, not cleaned.

Also check the shore power outlet. Ditto...any sign of blackening it will need to be replaced.

Also check the inlet on your boat. Ditto....any sign of blackening it will need to be replaced.

Also, check the screws inside the connector which tighten on the three wires -- be sure you're unplugged from shorepower when you do this. They often need tightening -- they should be really tight. While you're at it, check the condition of the wires inside those clamps.

Bill

[Mule]

I want to apologize before I do this, but I just cannot help myself.

Alternating Current. Is that kindda like a tide change?

Again...sorry.

[DennisM]

Thanks, btray. I will check all that stuff, too. Can't be too thorough, I'm discovering.

Mule, I'm shocked.

[DennisM]

I just had to come back to this thread and thank EVERYONE!! I followed David's, skipmac's and btrayfors' advice and found that it was indeed the connection that was the problem. I bought a new patch cord, tried a different connection on the shore power pedestal and triple checked the tightness of all elements, and voila! The panel behaved properly, the battery charger worked fine, and so did the water heater.

Thank you again!

[skipmac]

Congratulations. Glad it was not something more complicated or expensive.

You are now designated an expert third class and certified to give free advise to all and sundry on the forum.

[DennisM]

Hahahaha! Thanks skipmac. I tried giving advice about dripless connectors, because I am so happy with mine, compared with the old stuffing box I had. I soon learned that I still have a LOT more to learn.