Reverse Polarity Light - Red

C

crowleykirk

New member
Hello y'all:-)
Have our '23'C-Dory Venture at a slip this week. Hooked up shore power tonight. She is a new boat. First times I've connected shore power.

On the double switch, at the panel I'm getting a green light and a red light on the Reverse Polarity.

I don't think that is normal. Tried a different slips shore power, same thing.

I beleive we should be getting 2 green lights. Maybe something is hooked up backwards.

Thoughts?

Thanks
Kirk
 
I would start by isolating the problem - is it your boat, your cable/adapter, or the marina outlet. The red light on your boat is connected between neutral and ground, which are bonded together at the shore power transformer, but not on your boat (while you are connected to shore power). If hot and neutral are reversed somewhere at the marina then you will have 120 V between neutral and ground on the boat and a well-lit red light. I would begin by unplugging your shore power cable from the marina outlet and using a voltmeter to measure the difference between neutral and ground at the marina receptacle you were plugged into. If it's close to zero then the problem is either on your boat or your cable or any adapter you have on your cable.
 
crowleykirk":39s5inkd said:
... I beleive we should be getting 2 green lights. Maybe something is hooked up backwards. ...
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Don't know about your panel, but usually it is just one green light if things are ok. The reverse polarity light (mine is red) should not be on.

Unless you made your own shore power cable, I'd bet that the problem is in your boat.
 
Be very careful.

There are situations where the polarity light is on (red light) that are not particularly dangerous and likely easy to fix (e.g., polarity light is wired wrong), but that light can mean, and often does mean, that there is 120v full power on the neutrals (white wires) in your boat. If so, then the switches in, or to, any appliance will not stop the power going to the appliance when the appliance is switch off. Therefore there can be power at the appliance and the user won't know since the user turned off the switch (note the appliance does turn off when the switch is off thereby "fooling" the user, but appliance components will is still be energized via the voltage on the neutral which is not switched).
 
This is a new 2021 Venture 23. Turns out it was not with the boat at all. I "borrowed" another boats shore power cord, looked like it had been thru the wringer. Plugged it in and NO reverse polarity light.

So, just a bad "brand new" shore power cord supplied by the dealer.

Mike at the factory also said they tested it for several days with their dirty old power cord and all was good. The new one must of come from China. No way to take it apart for a repair. So I'll have to get. anew shore power cord.

Thank you all for the replies.

We are really on the fence about keeping her here in SoCal. Our plans really changed this year from the PNW to SoCal to help my wife's dad. Just not having the time to use her like we had hoped. And I've done so many modifications. Been fun last few days though:-)
 
That Shower power should be covered by the factory if it is a new one supplied by the factory or dealer responsible if supplied by dealer.

You can just put a new end on it, if you want. It will be much cheaper. I have made up new shore power cords, using new fittings with longer cords. Marinco new plugs run $57. (wow--a new cord is about $87...So may not be worth it. I have adaptors from China which were fine.

I sure would want to see where the problem was in the cord--you can do that by measuring continuity in each wire from plug to plug.
 
thataway":1qtuxp2l said:
That Shower power should be covered by the factory if it is a new one supplied by the factory or dealer responsible if supplied by dealer.

You can just put a new end on it, if you want. It will be much cheaper. I have made up new shore power cords, using new fittings with longer cords. Marinco new plugs run $57. (wow--a new cord is about $87...So may not be worth it. I have adaptors from China which were fine.

I sure would want to see where the problem was in the cord--you can do that by measuring continuity in each wire from plug to plug.
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Depending on where the problem is, if you end up repairing the cord I'd look into SmartPlug. You can change the boat end of the cord and the boat receptacle. I find the SmartPlug way better than the Marinco twist type.
 
The SmartPlug is a good unit, I installed it on Journey On.

That said, let me comment on two issues. One is that you're only changing the boat end; the dock end is the same as before. I had most of my problems with the dock connection, so using a SmartPlug doesn't fix that. I usually tie the dock plug in.

Second, if one stores the boat at home, the normal thing (for me, at least) is to use a standard 15 amp house extension cord to power the boat. That means buying or making up an adapter. Since the adapter sells for ~$170, I made one. So, add in the cost of another SmartPlug at ~$90, cable and 115 connector.

Boris
 
Since the adapter sells for ~$170, I made one. So, add in the cost of another SmartPlug at ~$90, cable and 115 connector.
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A 15/20 amp male to 30 amp marine adaptor is only $24 at Amazon (I carried two of these and two of the 30 amp female to 14 amp adaptors also). To loan to other boaters...Just plug your 30 amp smart cord into the adaptor,. Yes, you have too tie a piece of line to hold all of this together, but I do that any way...Or tape over the connection..
 
journey on":z0qd60r3 said:
.... Second, if one stores the boat at home, the normal thing (for me, at least) is to use a standard 15 amp house extension cord to power the boat. That means buying or making up an adapter. Since the adapter sells for ~$170, I made one. So, add in the cost of another SmartPlug at ~$90, cable and 115 connector.

Boris
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Or you can just get a standard 3 prong male to 30 amp female adapter, put a SmartPlug on it (or not), and just use a 20 amp extension cord to the shore power post. Most power posts have 20 amp plugs (and CBs) on them. If necessary you can get a 3 prong female to 30 amp male connector to connect the extension cord to the 30 amp outlet on the post.

The only time my boat pulls more than 15 amps from shore power is if the battery charger is on (and batteries depleted) and the AC is running. Almost never happens.

The 20 amp extension cord is lots easier to handle and store than the standard 30 amp shore power cord. I can't remember the last time I used it.
 
The only time my boat pulls more than 15 amps from shore power is if the battery charger is on (and batteries depleted) and the AC is running.
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This triggers an issue in my mind that I've never fully understood. I've made some assumptions about the issue, but I'd love to get some confirmation that my assumptions are correct, or equally valuable, that I am full of s**t :wink: .

At C-Brat Gatherings, I've always wondered why I see all these 30 amp cords running from C-Dorys to the power pedestal on the dock. On my CD25 the main breaker on the AC panel is 15 amps. I can easily trip that breaker if I run 2 power hungry appliances (e.g., the microwave, and the hot water heater) since they add up to more than 15 amps. So why do we all have 30 amp cords? What would be wrong with 20 amps cords (or even 15 amp cords) since that 15 amp breaker limits the total draw to a measly 15 amps. My assumption has always been that docks tend to have 30 amp outlets available, and boat builders are just used to installing those ubiquitous 30 amp receptacles on boats.

Any ideas?
 
I can easily trip that breaker if I run 2 power hungry appliances (e.g., the microwave, and the hot water heater) since they add up to more than 15 amps. So why do we all have 30 amp cords? What would be wrong with 20 amps cords (or even 15 amp cords) since that 15 amp breaker limits the total draw to a measly 15 amps. My assumption has always been that docks tend to have 30 amp outlets available, and boat builders are just used to installing those ubiquitous 30 amp receptacles on boats.

Any ideas?
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Yes it is sort of a "standard"--the 30 amp cord. There are times one will exceed a 15 or 20 amp draw, in the Normal business of a C Dory. There are only lighter duty 15/20 amp plugs--made for trolling motor chargers--such as I have on my 18'CC catamaran. The factory buys these cords and fittings at 60 to 70% less than retail price. There are a few boats which are using the boat end of Smart Plug or the EEL of Morinco

Not all marinas have the 15/20 amp plug--but most do. The major issue however remains the power cord. The 30 amp is sized to carry the 30 amps. Most extension cords are #14 wire--few are 12 and even less 10. I have a 50' 10 gauge extension cord rated at 20 amps, for my RVl. But I had to hunt for that. Thus I feel that the 30 amp cord (even if many don't use it-I do especially with the 25.
 
There are times one will exceed a 15 or 20 amp draw, in the Normal business of a C Dory.
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Can't on my boat.....at least not through the AC panel because, as I said, there is a 15 amp main breaker in the panel. It trips pretty close to 15 amps too (I know from much experience :wink: :lol:)
 
thataway":5wx2f3zq said:
I can easily trip that breaker if I run 2 power hungry appliances (e.g., the microwave, and the hot water heater) since they add up to more than 15 amps. So why do we all have 30 amp cords? What would be wrong with 20 amps cords (or even 15 amp cords) since that 15 amp breaker limits the total draw to a measly 15 amps. My assumption has always been that docks tend to have 30 amp outlets available, and boat builders are just used to installing those ubiquitous 30 amp receptacles on boats.

Any ideas?
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... Most extension cords are #14 wire--few are 12 and even less 10. I have a 50' 10 gauge extension cord rated at 20 amps, for my RVl. But I had to hunt for that...
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Got mine at Home Depot. 20 amps is usually 12 ga. A number to choose from.
For a 22, 20 amps seems plenty. Maybe on a 25 you'll find higher loads.
 
20 amps is usually 12 ga.
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Yeah, when wiring a house 12 ga is rated for 20 amp circuits (and 14 ga for 15 amp; 10 ga for 30 amp). But the manufacturers always seem to rate these "construction" type extension cords lower. I assume that's because these cords typically come with household NEMA 5-15 connectors which are rated at 15 amps. Perhaps what Bob is talking about is a cord with NEMA 5-20 connectors; in which case, I think it would be quite hard to find such a thing.
 
You should always use a power cable that is rated for 30 amps if you are connecting to a 30 supply even if your internal main breaker will trip at 15 amps. The 15 amp main breaker only protects components 'downstream' of it, it does not protect your input cable. For example, if you had a short where the cable plugs into the boat (water intrusion) and that short did not except 30 amps, no breaker would trip and, if the cable or plug could not carry 30 amps, you would be risking an electrical fire.
 
Karl Konecny":291mwoa8 said:
You should always use a power cable that is rated for 30 amps if you are connecting to a 30 supply even if your internal main breaker will trip at 15 amps. The 15 amp main breaker only protects components 'downstream' of it, it does not protect your input cable. For example, if you had a short where the cable plugs into the boat (water intrusion) and that short did not except 30 amps, no breaker would trip and, if the cable or plug could not carry 30 amps, you would be risking an electrical fire.
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The Marinco plug where the cord plugs into the boat is the most common point of electrical boat fires. This is due to wiggling of the plug, and then minor arcing, which builds up carbon and increases resistance, which makes the situation worse, and eventually over heating. If you are continuing with the Marinco plug, always screw the black plastic (some are Chrome metal) ring into the threads on the inlet to prevent movement. Or get the Smart Plug input. (there is more surface area) thus less arcing potential.
 
The Marinco plug where the cord plugs into the boat is the most common point of electrical boat fires.
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Tosca had just such a fire under its previous ownership. It was while the boat was in storage at his home. He felt lucky that he caught it in time.
 
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