Our new to us boat has only a 25 foot shore power cord. It is docked stern in. We would like to dock it bow in. I think that would require maybe 75 feet of cord lenght. Is it ok to connect the 25 ft cord to a new 75 ft cord? Do the connectors lock to each other ok?
Can shore power cords be connected to each other?
- Thread starter Njlarry
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Comodave
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Yes, I recommend a locking collar so they don’t come unconnected.
dhays
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I did that very think with my last sailboat. One power inlet on the boat in the stern. Docked bow in and the pedestal was on near the bow. Works well. Again, use dialectic grease for the connections then a sealing collar with Super Lube on the threads.
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AlaskaProf
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You'll encounter older marinas where power pylons are not conveniently located, (Shearwater, I'm looking at you) and you or they, or both have power cords snaking along the floats. Seems to work; but feel the cord for resistance heating.
tiltrider1
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I see no reasonable reason not to. However, doing so will not meet UL approval. The internal wires are sized for a 50' run. By connecting two power cords you now have undersized wires for the run length. Still the week link is the connection not the cord. Just understand, connecting two cords together reduces your safety margin.
It'll work fine, but you may see a voltage drop, and the increased resistance could lead to overheating. You shouldn't run a 30A cord continuously at 30A anyway, but for these extended lengths you want to be even more conservative. Maybe an electrical engineer will chime in with a rule of thumb.
dhays
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good points about the increased resistance with increased wire length. I never worried about it because the primary load was the charger and a few lights. If I was heating water and running 120v appliances, I'd be more concerned.
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Good advice and comments. I would minimize loads if having to use an "extra long" cord set up. I have seen people use electrical tape to help "seal" the joint where the 2 cords are joined. AlaskaProf, I first saw this in Shearwater.
Alaskaflyer
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The chart I have says that in order to stay below a 3% voltage drop, 10 gauge copper - which is what most 30 amp shore power cords use - is only listed for up to 50 feet. 8 gauge for up to 75 feet, 6 gauge for 100 feet, 4 gauge above that. This doesn't include resistance of any additional connectors such as when daisy chaining two or three cords.
Back to the OP, probably a better solution would be to install a new power inlet on the boat, closer to where you want to plug in at your home dock. Keeping the old one (with proper isolation switching) would allow you to connect at the most convenient outlet wherever you tie up.
dhays
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Agreed. If I had kept my sailboat, I would have eventually added a power inlet in the bow locker. So regardless if I was bow in or stern in, I would be closer to the power pedestal.
Maybe closer to the boat inlet and more convenient but wire run not much different if power distribution panel aboard is still a boat length away. Is there really a difference between power cord or installed wiring? To me it depends on length of run of a given wire gauge and amps carried... no!
I thought about this. I still come down in favor of the internal wiring. It can be a heavier gauge, which does away with the problem of cords not having adequate wire sizes for the 75' run. The inside section doesn't need weatherproof cladding and is protected from dock hazards like pinch points and having heavy things landing on it. The wires can be properly and permanently terminated in an enclosed space. The connection of the two cords, even with the proper connector, is nowhere near as reliable.
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10 gauge wire is still 10 gauge whether it is in a power cord or inside the boat. Have good connections on the cables and I don’t see much difference. With L5-30 connectors you should not exceed 80% of the 30 amps for any lenght of time.
dhays
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I was actually thinking about that as I typed my post. I was wondering that if I had installed a power inlet in the bow that I would need to upsize the wire from what was used in the stern to account for the distance as you mentioned.
However, I then realized that in my sailboat, the length of the wire run from the inlet in the stern to the panel in the boat, would be about the same as the run from a new inlet in the bow locker since the panel is located in the main cabin which is near the midpoint.
My current boat has a power inlet on the starboard side, just a few feet from the electrical panel in the pilothouse. However, the power inlet in the stern is quite a bit further. My guess is that the same gauge wire is used.
Comodave
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Just remember that ABYC recommendations are that there is a breaker within 10’ along the wiring from the inlet.
Thats true but easily accomplished with a surface mount, properly sized,, Wx tight CB designed for that exact purpose.
You should also install a transfer switch that selects the inlet to be connected and the one to be disconnected. That may be a little more work to accomplish.
CaptTom & dhays... you make excellent points about uprising wires that I agree with and are worth considering in the whole design / decision process.
The simple answer is, yes, you can connect two power cords together to make a longer cord. Remember though, the longer the power cord, the greater chance of a voltage drop and your air conditioner may receive the voltage it need to run properly. In any event, the shore power cable should be kept as short as possible to reduce voltage drop.
If this is a permanent slip, you could use a 50' 50 amp cable and then a 30 amp adapter and a 30 amp cord from there to the boat. This would reduce the voltage drop. (I am assuming a 30 amp boat here).
Adding an additional power inlet to a boat is not as simple as it might seem. First, you would need a three pole switch to switch from the original to the added inlet because without a switch, the pins on the unused inlet would be electrically "hot" and could kill somebody.
Second, you would have to install additional overcurrent protection within 10' (measured along the wires) of the inlet.
And of course, you would need to use ABYC electrical practices and appropriate cabling and boxes.
If this is a permanent slip, you could use a 50' 50 amp cable and then a 30 amp adapter and a 30 amp cord from there to the boat. This would reduce the voltage drop. (I am assuming a 30 amp boat here).
Adding an additional power inlet to a boat is not as simple as it might seem. First, you would need a three pole switch to switch from the original to the added inlet because without a switch, the pins on the unused inlet would be electrically "hot" and could kill somebody.
Second, you would have to install additional overcurrent protection within 10' (measured along the wires) of the inlet.
And of course, you would need to use ABYC electrical practices and appropriate cabling and boxes.
ProMaritime
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If he needs 75 feet of cord why would he connect a 75 foot cord to his 25 foot cord? Looks like a total of 100 feet to me.
ProMaritime
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I quote the original poster: "Is it ok to connect the 25 ft cord to a new 75 ft cord?" Still looks like 100 feet to me. RTFM brother.
Nepidae
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First, you should know that most boat fires start at the shoreside receptacle. With that in mind, you should be conservative with what you are planning.
25' shore cord is short and most are 50'. Did the previous owner make the cord up? I am not a fan of DIY made-up cords. To me, the cost of a manufactured cord is cheap insurance.
When we bought our boat and after some reading, I put SmartPlug boat side receptacles & cords (https://smartplug.com/) on our boat. Easy DIY project and with a twist lock shoreside end you can connect a standard shore cord to get up to 100'. I have 1 but haven't used it yet (about 10yrs of having it).
I didn't see if you had a 30 or 50A boat but with 2 -30A (1 for the house & 1 for A/C) we also carry a 50A splitter for those times a 50A is the only shoreside receptacle available.
I also carry a 100' 10g extension cord and used it in Canada once to connect to a 15A outlet that was on a dock. Couldn't run A/C but in Canada, even in the summer, A/C wasn't necessary. With adapters, you can set yourself up to connect to almost anything.
We are on the Loop & I wanted & needed to be able to meet and attach to just about any connection we might encounter.
In closing, I might also suggest that you consider the addition of an ELCI. Marinas are installing new pedestals that are ESD compliant and it would be a good idea (the 25' shore cord has me a little worried) to have your boat checked over before an ELCI is installed. Reverse polarities could cause you issues down the waterway.
BTW, we bow in all the time and usually do a port side tie due to our boarding gate.
I see you are in Rock Hall, an interesting approach to that spot. Been there several times.
Good luck with your boat projects, they never end. Let me know if I can be of any further help.
25' shore cord is short and most are 50'. Did the previous owner make the cord up? I am not a fan of DIY made-up cords. To me, the cost of a manufactured cord is cheap insurance.
When we bought our boat and after some reading, I put SmartPlug boat side receptacles & cords (https://smartplug.com/) on our boat. Easy DIY project and with a twist lock shoreside end you can connect a standard shore cord to get up to 100'. I have 1 but haven't used it yet (about 10yrs of having it).
I didn't see if you had a 30 or 50A boat but with 2 -30A (1 for the house & 1 for A/C) we also carry a 50A splitter for those times a 50A is the only shoreside receptacle available.
I also carry a 100' 10g extension cord and used it in Canada once to connect to a 15A outlet that was on a dock. Couldn't run A/C but in Canada, even in the summer, A/C wasn't necessary. With adapters, you can set yourself up to connect to almost anything.
We are on the Loop & I wanted & needed to be able to meet and attach to just about any connection we might encounter.
In closing, I might also suggest that you consider the addition of an ELCI. Marinas are installing new pedestals that are ESD compliant and it would be a good idea (the 25' shore cord has me a little worried) to have your boat checked over before an ELCI is installed. Reverse polarities could cause you issues down the waterway.
BTW, we bow in all the time and usually do a port side tie due to our boarding gate.
I see you are in Rock Hall, an interesting approach to that spot. Been there several times.
Good luck with your boat projects, they never end. Let me know if I can be of any further help.
