Has anyone ever cut off and replaced the end of their power cord?

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No one has mentioned the anti-corrosion goo you can use in connections. Formulations come in many flavors and for various dissimilar metals.

Ditto the comments about checking both sides of a plug-receptacle when one side is exhibiting distress.
 
I will probably :( go ahead and buy 2 new 25ft 30amp cords and 2 new power inlets for the boat. After looking closely at the circuits, it's time to replace. As I sit here running both A/C units I can't help but think about those old plugs and outlets :facepalm:
 
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In my case, I am religious about spraying both ends of the cord with CRC 656 at every use. When I saw the inlet temperature rising. I applied a very light coat of Kopr-Shield conductive paste. It did not help. then i took the hull inlet out. two of the clamp screws were loose. So I took the unit off, applied Kopr-Shield to the tinned 6 ga. boat cables and reconnected it all. Still had a 25 degree delta. So I replaced the hull inlet with a new Marinco inlet. again Kopr-Shield as above. Now the delta was 19 degrees. I was at this time pulling 26-28 amps through the cord for 30 minutes before I recorded the temperature after each change in the system. When my new smart Plug inlet was installed the temperature differential dropped to 3.5 degrees. That is pretty convincing data as far as I am concerned.
 
tadhana said:
How do you see power at a glance?
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Smart Plug cords have a LED in the boat end that lights up if the shoreside power is on.

I have Smart Plug systems on both boats and find that they are easier to use.
 
tadhana said:
In my case, I am religious about spraying both ends of the cord with CRC 656 at every use. When I saw the inlet temperature rising. I applied a very light coat of Kopr-Shield conductive paste. It did not help. then i took the hull inlet out. two of the clamp screws were loose. So I took the unit off, applied Kopr-Shield to the tinned 6 ga. boat cables and reconnected it all. Still had a 25 degree delta. So I replaced the hull inlet with a new Marinco inlet. again Kopr-Shield as above. Now the delta was 19 degrees. I was at this time pulling 26-28 amps through the cord for 30 minutes before I recorded the temperature after each change in the system. When my new smart Plug inlet was installed the temperature differential dropped to 3.5 degrees. That is pretty convincing data as far as I am concerned.
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Don't know what would be the upper limit of your normal load, but if I were pulling much above 20 amps I would be switching to a 50 amp service from the panel out. Wouldn't need to change the main panel or the breaker. I like the smart plug design, but as mentioned, it does nothing for the power pedestal connection. In a better world, boat manufacturers should switch to building with the 50 amp connection and appropriate wiring to the boat panel.

Ted
 
O C Diver said:
Don't know what would be the upper limit of your normal load, but if I were pulling much above 20 amps I would be switching to a 50 amp service from the panel out.

Normally when we are on one single 30 cord, we are pulling about 15 amps or even less. In this case I was intentionally pulling a heavy load for a long time. I ran the batteries down to 70% SOC, then turned on the AC and the water heater and then slowly cranked up the output of the charger so that I could achieve and hold a heavy load near the upper design limit of the connections. I want to know that my hull inlet is not going to burst into flame one night when I am sleeping. When we are living on just one cord, we do have to manage our loads becasue short term loads like the micro wave can easily push it over 30 amps and then a beaker shuts off. I wanted to see what the equipment could take and what sort of temperature differential it would create. As a general rule a 10 degree differential is worth noting and a 20 degree differential is telling you something has to change. I initially saw 30 degrees on the inlet using the load i had intentionally created.
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bcam said:
Smart Plug cords have a LED in the boat end that lights up if the shoreside power is on.

So you are connecting the dock to the hull inlet with the dock breaker turned on? If the boat's inlet breaker is on then you will draw a spark as you connect the cord. Over time doing that you will build up resistance in that connection. We always advise to turn off the power at both ends of the cord and make the connections with a dead cord. Then turn on both connections once the connection is made. The hull inlet breaker will light up and tell you the connection is power is on. Also some cords have an LED in the plug end so once the boat connection is made the shore pedestal breaker can be turned on and you will see that blue or red led indicating power is on.
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Smart plugs are far too expensive and will never take over .

The cheapest concept is to install a 50A240V plug and inlet on the boat and keep the std 30A 120v power cord and dock end.

When you overload/or corrode, the dock CB should blow or at least the fire will be at the dock , not at your power inlet.

240V 50A inlets and plug ends can be found used.Avoid SS pins if you can.

There is an ancient 120V 50A plug and socket style that could work for the boat inlet , but IF you are going to buy it new , might as well spring for the 240 /50 as eventually it may be needed for an upgrade.
 
Ohms law dictates, double the volts then half the amps for the same load and visa versa. Whack a mole.

Amps is where the heat comes from. 50 Amps at 240 is like 100 amps at 110, right? so I think you are on to something here FF, at an affordable price. Just go to home depot and pick up a dryer plug, male and female.

Now for the fly in the ointment. How will this play for the surveyor and insurance company? Electrically you are solid.
 
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Mule said:
Ohms law dictates, double the volts then half the amps for the same load and visa versa. Whack a mole.

Amps is where the heat comes from. 50 Amps at 240 is like 100 amps at 110, right? so I think you are on to something here FF, at an affordable price. Just go to home depot and pick up a dryer plug, male and female.

Now for the fly in the ointment. How will this play for the surveyor and insurance company? Electrically you are solid.
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Actually the 50A 125/250 circuits are just 2 legs of 110 Volts each.

If your boats electrical panels aren't set up for it, it may not be easy or cheap to take advantage of the additional power available.

All I think FF is talking about is using the heavier duty common plug versus a Smart Plug.
 
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Nomad Willy said:
I just mangled the male end of my power cord. Again. This time even one of the metal connectors was missing. Every now and then I untie the mooring lines and back out w/o thinking about the power cord. Too many years of running smaller boats w/o power cords I guess.
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O C Diver said:
Might be time for a departure check list.

Ted
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Eric, one is only allowed so many 'senior moments' then questions need to be asked, my friend...:D
 
psneeld said:
Actually the 50A 125/250 circuits are just 2 legs of 110 Volts each.

If your boats electrical panels aren't set up for it, it may not be easy or cheap to take advantage of the additional power available.

All I think FF is talking about is using the heavier duty common plug versus a Smart Plug.
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Yes, I agree. The 50A/240V twistlock plugs and receptacles are very robust. The only place a Smart Plug makes any sense is when replacing a 30A plug set. But to me, going non-standard is a huge down-side. The North American standard plugs are available pretty much anywhere if you need to replace one, you can get a replacement power cord pretty much anywhere, and you can use any combination of different length cords, including those borrowed from friends. With any non-standard plug set on your boat, you are now limited to one cord, one length, carried by you. You just created a single point of failure.

Going to a 50A/240V inlet on your side of the boat, even if you only use one leg of the 120/240 circuit, and even if you use adapters to get back to a standard 30A cord, you have accomplished all the same things as a Smart Plug, but done so using standard parts.

Oh, and getting back to the original question.... I've generally found that it's only a small amount more to just replace a whole 30A cord vs replacing the end plug. It depends a bit on the cord length, but $70-$90 for a whole cord set and probably half that for one cord end. And the factory made cord sets usually have molded plugs so better water intrusion protection. 50A cords are a whole different story where the cord set costs $500-$700, and a plug end costs $90.
 
." Just go to home depot and pick up a dryer plug, male and female."

That works just fine INSIDE for changing the boat from shore power to noisemaker power to inverter power.

INSIDE is the key.

A 240V 50A MARINE plug and socket is water proof if you do it properly.Hubbel is always my only choice.

The 30A power cord will not over load the 50A 240V marine unit , esp if you split the load and wire both pins to operate together.

The 50A pins and socket should be pretty cool with 15A as a max load..

The use of dryer items inside the boat should not bother your insurance guy , as it is an excellent simple system to use.
 
Mule said:
Gimme some guidance here. I have 30 amp service. Looking on line at "smart plugs" it appeared the plug pattern was different than my standard, locking Marinco cord and female on boat side. Also the replacement plugs are EXPENSIVE. On sale I find 30 amp cords +- $70. What am I missing?
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See my earlier post re insurance co rebates. Made my conversion cheaper than buying one new end by Marinco.

I now have one cord with a smart plug female end to the boat that has the smart male end. That cord has a standard Marinco plug on the other end, that I will replace when it starts to show deterioration from sparky dock fittings. I have spare cords for longer runs, that are only fitted with standard Marinco ends.

I always make sure the boat breaker is off when connecting or disconnecting, at the dock. Likewise I always disconnect at the dock before I disconnect at the boat, and vice versa for reconnecting. This will save my smart ends from sparks and limit the dock end damage.

At my YC Moorage, we have a display board with several badly burned cord ends, both male and female. So far nobody has burned a Smart end to add to the display. Hope it stays that way.
 
FF said:
Smart plugs are far too expensive and will never take over

The cheapest concept is to install a 50A240V plug and inlet on the boat and keep the std 30A 120v power cord and dock end.

When you overload/or corrode, the dock CB should blow or at least the fire will be at the dock , not at your power inlet.

If you are going for the cheapest solution, the cheapest and most reliable solution is to have a permanent bolted connection inside the boat.

If you have corrosion and resistance in the connection, the circuit breaker will not trip. You can have a fire while drawing 20 amps through a corroded 30 amp plug connection. The breaker trips on current overload and not heat in the inlet.
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stanfromhell said:
Bacchus is 100% on the right track. You don't need to just change the discolored connector, you need to resolve the problem that caused it, which was too many amps going thru one or all of the terminals or connections at one of the plugs. High amperage draw is caused by corrosion, broken wire strands or loose connections. ............
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High amperage draw is not caused by corrosion, broken wire strands or loose connections. High amperage draw is caused by using too much current. And, the amount of current is the same for the hot and neutral conductors and connections. The ground connection should see no current unless there's a fault.

Corrosion, broken wire strands or loose connections will cause excess heat and possibly arcing which will destroy some of the metal the connections are made of.

Quite often, corrosion or signs of arcing on your shore power cord's male end are caused by worn out connections on the dock pedestal.
 
koliver said:
See my earlier post re insurance co rebates. Made my conversion cheaper than buying one new end by Marinco.

I now have one cord with a smart plug female end to the boat that has the smart male end. That cord has a standard Marinco plug on the other end, that I will replace when it starts to show deterioration from sparky dock fittings. I have spare cords for longer runs, that are only fitted with standard Marinco ends.

I always make sure the boat breaker is off when connecting or disconnecting, at the dock. Likewise I always disconnect at the dock before I disconnect at the boat, and vice versa for reconnecting. This will save my smart ends from sparks and limit the dock end damage.

At my YC Moorage, we have a display board with several badly burned cord ends, both male and female. So far nobody has burned a Smart end to add to the display. Hope it stays that way.
Click to expand...


On my sailboat when I made the switch I bought a Smart Plug cord (standard 30 amp male and for the dock and a Smart a Plug female end for the boat) then I changed out the female end of my existing cord for Smart Plug female. I always like having two power cords, one to leave on the dock and the other in the boat that goes with me. This is not only for convenience, but I consider it a safety factor as well. The dock pedestal at my old slip had a very worn 30amp female plug. It didn't have locking ring threads and didn't fit tight. I ended up using some small stuff to tie the cord tightly the pedestal so there was no movement and used dialectic grease on the connection. Plugging and unplugging a 30amp cord causes wear over time. That can lead to a poor connection and that can lead heat. I want a solid connection that remains untouched other than for inspection a couple times a year.

I did like the led at the female end of the smart plug. There are some docks where it can be hard to tell if the breaker is on at the pedestal. If you plug into the pedestal and the led lights up, then you know it is live. If you can't find where to turn it off, then you can unplug it and then plug into the boat first, turn off your boats breaker,then plug into the dock carefully.
 
tadhana said:
FF said:
If you have corrosion and resistance in the connection, the circuit breaker will not trip. You can have a fire while drawing 20 amps through a corroded 30 amp plug connection. The breaker trips on current overload and not heat in the inlet.
Click to expand...

This is true. A 30 amp breaker will not trip at 31 amps, it takes a significant fault current above 30 amps to trip it.

I put my hand on the plug body to check the temperature and wiggle it to make sure the clamping ring is still tight. Sorta like checking trailer hub bearings for heat when you stop to fill up for gas on the freeway, quick look at the tires, etc.

Regarding amps: I got one of these and it has turned out to be one of the most used tools on the boat, it measures AC and DC amps up to 100 amps, and is so sensitive to 2 or 3 decimal places, making it useful for tracing down small currents too. Compact and fits into the small spaces on the electrical board...

Uni-T UT210E True RMS AC/DC Current Mini Clamp Meters w/ Capacitance Tester

Cut and paste that into Amazon or your favorite site.
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HopCar said:
It is a very easy job. The terminal screw heads are color coded so it's hard to get it wrong. .
Click to expand...

Most of my career involved electricity and repairing things that were often screwed up by the owner or used. They can and do get it wrong.
 
tadhana said:
How do you see power at a glance?
Click to expand...

Touch it and you see stars. ;)


I'm guessing that the boat end has a pilot light but some "standard" cords do as well. Of course, to be safe and follow the directions, one would never turn on the dock breaker before plugging in the boat end so any though of using the light to find the socket on the boat would be a very bad idea.
 
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FF said:
Smart plugs are far too expensive and will never take over
Click to expand...

I'd like to ask those who posted that they prefer Smart Plugs: Why?

I'm not trying to start an argument. And I'll accept the possibility that I'm just being cynical about it. But frankly, I don't see a huge benefit to ME. I see lots of benefit for the company which wants to replace every dock and vessel power inlet and outlet in the world.

And yes, I've seen overheated connections, and even caused one once. I know it can and does happen. I'm not convinced it can't happen with a Smart Plug.

To me a truly "smart" plug would (1) work with existing dock outlets and boat inlets, (2) be easy to connect without stripping threads or coming unlocked, and (3) reduce the possibility of overheating.

If I could phase in the implementation, I'd certainly pay extra for these qualities. But I'm not scrapping every component I already own, and I'll be very upset if I pay for a slip at a marina that requires me to buy something new before I can plug in. I have too many adapters already!
 
CaptTom said:
I'd like to ask those who posted that they prefer Smart Plugs: Why?
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Significantly larger contact engagement surface.
Better locking system
Easier to connect

While I really like the system, I probably won't be changing my 50 amp connectors over to them. 50 amp 240 twist lock marine plugs are far better than their 30 amp cousin.

Ted
 
CaptTom said:
I'd like to ask those who posted that they prefer Smart Plugs: Why?
Click to expand...

These are the reasons I did it. Again, they were reasons important to me and not everyone would find them sufficient reasons to change.

1. Increased safety.
2. More solid connection (very tight and secure)
3. More convenient and faster to plug in, even in the dark.

It isn't cheap, but then I have a lot of things on my boat that are a lot more expensive that are there to add safety and/or convenience.
 
O C Diver said:
Significantly larger contact engagement surface.
Better locking system
Easier to connect

While I really like the system, I probably won't be changing my 50 amp connectors over to them. 50 marine plugs are far better than their 30 amp cousin,
Click to expand...

Great minds.....

I haven't yet changed out my 50amp/120v plugs on my current boat for the same reason.
 
CaptTom said:
I'd like to ask those who posted that they prefer Smart Plugs: Why?

I'm not convinced it can't happen with a Smart Plug.

If I could phase in the implementation, I'd certainly pay extra for these qualities. But I'm not scrapping every component I already own, and I'll be very upset if I pay for a slip at a marina that requires me to buy something new before I can plug in. I have too many adapters already!
Click to expand...

CaptTom
Have you looked at the Compass Marine comparison?
Best 3rd party review I've seen.
I believe the benefits... haven't switched yet but will when I need a new inlet.
You can "phase in" w/o scrapping everything! Smart plug is for boat end not marina pedistal and you can get plugs to retrofit ypur cords.
It sounds like your mind is made up and that's ok. I've had & seen too many bad cord boat ends that I would rather mnimize the chance of a meltdown or fire on my boat. ..
 
For 30 Amp ends.....

Let's be fair to the whole discussion....
 
Every now and then I untie the mooring lines and back out w/o thinking about the power cord.

It's called the yellow spring-line for a reason
 
Our primary power inlets are 50A, and I see zero benefit to change them. As others have pointed out, they already have all the positive attributes of a Smart Plug, cost less, and most important, are a standard.

But we also have a 30A inlet that converts on-board to 240V so we can run at reduced power off 30A/120V is that's all that's available. But I also don't see a compelling reason to change that to a Smart Plug. I get the benefits of a Smart Plug and don't dispute them, but don' think the down-side is worth it. First, the boat-side connection is the one that I can control and prevent from becoming damaged by hot plugging, not twisting to lock, overloading, etc. Of the two ends of cord, to me, it's not the problem end. And if it does become a problem, I'll just replace it. The problem-end is at the dock, and more importantly the dock receptacle. And like it or not, I have to live with that, Smart Plug or not.
 
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