Replacement Shore Power Cord

[hiflight]

I decided to replace my tired power cord, ordering one from Marinco via Amazon. When installed, it showed a (weak) "reverse polarity" light on the panel. I broke, and remade the connection several times, and made sure all connections were proper, with no improvement.
I contacted Marinco tech support and was told that has happened sometimes and might be a false indication as the light was showing weak. I'm reluctant to press on with it in this mode as I don't know what other issues I might be looking at if I'm wrong.
Does anyone know how to check this out to be sure if the new cord is OK or defective? Thanks.
Mike

 

[Jerry VB]

Buy an inexpensive "plug in AC receptacle tester" from your local store - $10-$15. Home Depot example. Plug in your shore power cable and then plug in the "receptacle tester" into an AC outlet on the boat. Instant second opinion!

Marina power pedestals typically have two outlets to service two slips. If you can "borrow" your neighbor's outlet, see if it gives you a different result. If so, your outlet is likely broken/miswired. If you can reach a different pedestal, check plugging into that - tests if your pedestal is broken/miswired.

Based on a dim light, I would be concerned that the neutral wire (cord, on your boat, or in the pedestal) is faulty (perhaps higher than normal resistance) so that there is current flowing through the safety ground wire. That is unsafe! You can use an ohm meter to measure the resistance of each of the wires end-to-end in your new cable. They should be nearly identical and nearly zero.

Good Blue Sea references:

• Reverse Polarity Indicators
• AC Reverse Polarity

 

[hiflight]

I should have mentioned, in my opening, that I removed the new cord, and put my old one back on, with no indication of any problem.
Thanks for the repluy.

 

[Jerry VB]

I should have mentioned, in my opening, that I removed the new cord, and put my old one back on, with no indication of any problem.

Good. That pretty strongly implicates the new cord but it could be a weak or bent connection on the pedestal or on your boat's inlet which contacts your old cable's contacts OK but not the new cable.

I am really wary of a "weak reverse indicator light is a false indication" response. If the light is on, there is current flowing where it ought not to flow.

 

[markvone]

I would check the wire connections on the boat socket side. Mine showed reverse polarity "for no reason" one day for the old cable and socket. See thread below.

Shore power?

Visited the boat on Sunday and found I had no shorepower. Cord is connected and solid, but no "service" light on the AC panel. Cycled the breaker, no joy. Called the marina office and asked them to check the power pole. They called back this morning and said power at the pole is fine. So...

ericsonyachts.org

The old Marinco shore power cable and socket design is horrible and living on borrowed time. If anyone in the past has been a big power user, i.e. running enough loads for over 20 amps for any length of time, I'll bet there is damage due to heat. I'd return the new cable and apply the funds toward a new Smart Cord and Plug. Just my 2 cents.

Shore Power Cords - SmartPlug vs. 1938 by Compass Marine How To

www.pbase.com

Mark

 

[G Kiba]

Same 2 cents from me. I sleep better aboard plugged in with my Smart Plug. Although all around me at my marina, Home Depot extension cords seem to abound? I am surprised that marinas don't have rules about shore power cords.

 

[Nick J]

The importance of the SmartPlug can't be overstated. I installed one on my previous boat, but thought I could wait on the new one. At inspection, the cord looked fine, a year later I found this:



I've posted this before, but I don't think we can have too many reminders of how dangerous these plugs can be. The article Mark posted above says it all.

 

[toddster]

Well... it's true that my cord is getting pretty old. And I did just receive the annual admonition newsletter on this subject from the marina manager... Maybe today's the day. I can't help but think though, that the other end of the cord is still the same "old fashioned" connector.

But that sounds like a pretty flaky response from customer service.

 

[gabriel]

https://www.bluesea.com/resources/84