Another power plug mishap.....
- Thread starter Redhook98
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Comodave
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Why not go ahead and fix the problem instead of going back to the same type of plug that you are having trouble with now? Why put money into 1930s technology that will go bad again?
Comodave
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Ok, so fix it all at the same time. But why put another plug that has know problems back on? I don’t want to be asleep on my boat when the L5-30 plug catches fire. On a previous boat there was a fire caused by one of the old plugs which fortunately went out by lack of oxygen.
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Are the male prongs on the boat inlet clean, no corrosion or pitting?
If none of the above, then I would just install a new standard 30 amp female plug on the cord. Make sure to install the locking collar boot that comes with the kit.
With clean contacts and a locking collar, standard 30 amp shore inlets are fine. The locking collar on the Marinco 30 amp cord on the boat end has tabs instead of threads. The inlet fittings has corresponding notches so only a 1/4 turn or less to securely tighten.
If you want an easier connection, Marinco's EEL (Easily Engaged Lock) offers a one handed clamp design similar to Smart Plugs.
Whether you have a standard or Smart Plug inlet on your boat, I would mount the inlet on a metal plate with a metal enclosure behind it.
With either type of 30 amp connection, clean contacts are still essential. Many boaters never disconnect the boat end.
If none of the above, then I would just install a new standard 30 amp female plug on the cord. Make sure to install the locking collar boot that comes with the kit.
With clean contacts and a locking collar, standard 30 amp shore inlets are fine. The locking collar on the Marinco 30 amp cord on the boat end has tabs instead of threads. The inlet fittings has corresponding notches so only a 1/4 turn or less to securely tighten.
If you want an easier connection, Marinco's EEL (Easily Engaged Lock) offers a one handed clamp design similar to Smart Plugs.
Whether you have a standard or Smart Plug inlet on your boat, I would mount the inlet on a metal plate with a metal enclosure behind it.
With either type of 30 amp connection, clean contacts are still essential. Many boaters never disconnect the boat end.
Andy G
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This thread is a great source of information, obviously quite a few knowledgeable types posting here.
One question though. A lot of posters here seem to be doing their own electrical work, not just on the 12 volt side but the AC as well. Over here(OZ) is is illegal to do any work on the AC side of supply if you are not a qualified electrician. Any non authorised electrical work also potentially voids you insurance as well. What are the rules in the US?
One question though. A lot of posters here seem to be doing their own electrical work, not just on the 12 volt side but the AC as well. Over here(OZ) is is illegal to do any work on the AC side of supply if you are not a qualified electrician. Any non authorised electrical work also potentially voids you insurance as well. What are the rules in the US?
O C Diver
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Electrical wiring laws for buildings are written by individual states, counties, and cities etc. Federal laws for boats apply for commercial applications or inspected vessels. ABYC regulations are maybe described as best practices as they have no criminal standing if violated. With regard to insurance policies, there isn't a standard for recreational boats.
Ted
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In the US, doing work for hire would be an issue. But doing it for yourself is fine. In the case of a house, if it's part of any significant house modification it would need to be inspected at the end of the job. But for small stuff, no such problem.
angus99
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Some of us who do our own electrical work do so under the guidance of an ABYC-certified electrician. In my case, I had him redesign the system from the battery banks to the distribution panels, engines and—in some cases—beyond. He helped me determine loads, size the wiring and breakers/fusing and make sample crimps before I got started. He also did a full inspection before we energized. Many, many phone and email consults and the job took forever, but I learned more about our wiring than I ever would have otherwise.
sunchaser
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TF and many other online sources suggest a myriad of DIY fixes for wiring issues. Some are correct but not all. The genesis of this thread is a DIYer wiring job.
The approach used by Angus 99 seems spot on - use a pro to assist or otherwise check things out. Three years ago we had a top notch marine electrician go through all our 110/250 volt systems. Not all were in order especially grounding systems to deal with the new 30ma kGFCI dock codes.
The approach used by Angus 99 seems spot on - use a pro to assist or otherwise check things out. Three years ago we had a top notch marine electrician go through all our 110/250 volt systems. Not all were in order especially grounding systems to deal with the new 30ma kGFCI dock codes.
I would definitely change out my old dual 50’ twist lock 30 amp power cords for Smart Plug cords and boat inlet receptacles IF they offered a dock power station twist lock to Smart Plug adapter. I don’t want to spend $700 +- on Smart Plug power cords with the old style dock power station twist locks. So if and when Smart Plug offers adapters or marinas start installing Smart Plug in the pedestals I will be cleaning and servicing my old cords and plugs.
I’ve seen plenty of cord ends burnt because of resistance problems. The only dock power cord fire I ever witnessed was caused by loose internal power wires in the boats power inlet receptacle. That’s worth taking loose and inspecting. I saw one boat that the ground wire had come loose on, it was caught by a good surveyor. The wire end had dust on it indicating it had been loose for a long time.
I’ve seen plenty of cord ends burnt because of resistance problems. The only dock power cord fire I ever witnessed was caused by loose internal power wires in the boats power inlet receptacle. That’s worth taking loose and inspecting. I saw one boat that the ground wire had come loose on, it was caught by a good surveyor. The wire end had dust on it indicating it had been loose for a long time.
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TexasBryan
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I was having intermittent electric problems and found that one of the legs of the Marinco power cord was fried and almost welded to the boat.
I took the opportunity to replace the Marinco with the Smart Plug. The 50A 125/250 inlet and connector kit was ~$270. Other than difficulty dealing with the heavy gauge wire, the swap-out was easy and only took about an hour.
I am pleased with how securely the Smart Plug connects and it seems to have resolved the electrical issues.
I took the opportunity to replace the Marinco with the Smart Plug. The 50A 125/250 inlet and connector kit was ~$270. Other than difficulty dealing with the heavy gauge wire, the swap-out was easy and only took about an hour.
I am pleased with how securely the Smart Plug connects and it seems to have resolved the electrical issues.
I have no idea why, but it seems that the boat end of the cord seems to experience the lions share of the issues. I suppose it’s as simple as that end simply moves more. Also always interesting how different the experiences between the east coast/PNW. I would have figured that while there are fewer heaters being left running in the winter, you would have made it up with AC. In the Seattle area, we have a major boat fire pretty much every winter and with my boat under cover, I’m necessarily paranoid.
Here was the Marinco cord directly across from me this winter and it was not yet hot to touch, but the securing ring was the usual mess. Still trying to get him to replace this old cord.
Codger2
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I find these posts that people are switching to Smart Plugs to be quite interesting. When Smart Plug first came out I bought & installed one on my 32' Halvorsen Gourmet Cruiser. It worked great and I wrote about it here, on TrawlerForum. The responses to my post were anything but positive. Guys came out of the woodwork to extol the virtues of the old style plugs. I felt bad for the Smart Plug people as their product was obviously superior to the 40 year old design that continues to plague boat owners to this day. It makes me happy to see that the old style is being replaced in increasing quantities as the days & weeks roll on. No, I don't have a financial interest in Smart plug, I'm just a very happy user!
Comodave
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I am not sure why people defend the L5-30. It’s not like they invented it. The Smart Plug has obviously better contact. Oh well, you can take the camel to water...
FoxtrotCharlie
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If we had 30 amps I would have already changed to Smart Plugs, but we have 50 amp, and have no issues, as the old style 50 amp plugs are very robust and much more secure with the grounding ring. Our boat inlet is below our hand rails, so I always support the cord with a small line tied up to the hand rail, taking all weight off of the plug/fitting.
I remember. It was a bit of a turd show, with one poster specifically bullying, then sniping on other threads to harass. Pretty effective at shutting down any constructive discussion.
TexasBryan
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Comodave
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Definitely time to upgrade...
diver dave
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Some temperature rise is inevitable. You have the total pseudo color range set to only 9 deg.
I do the whole dock. It’s pretty apparent when you get one that is different than the others. What’s interesting about this one is not the rise at the connection, but the rise deep in the cord. Like I said, this one was not hot to the touch yet. But I’d bet you money you will find corrosion wicking through the cord if you peeled the insulation back.
The whole point is to find the issues before they get to be a problem.
The whole point is to find the issues before they get to be a problem.
It's an 80 year old design, created so aircraft factories during WWII could move equipment around the shop floor.
rslifkin
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It's hard to say if this one is just under more load than the others. Realistically, if the hottest point on it is still only a few degrees above ambient, I wouldn't call it a problem. It might be worth cleaning the contacts to see if that improves it, but a little bit of heating is normal in any connection being run close to its rating. Feel the plug from your vacuum cleaner after 15 - 20 minutes of vacuuming and I bet you'll find it warm, even if it's brand new and plugged into a new outlet.
diver dave
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Intelligent use of IR thermos are a great aid to find bad wiring and connections. Note that when a manufacturer rates current capability for their connectors, they also spec a wire size. Most always, the connector will dissipate heat that needs to be sunk by the attached wire. Of course, the wire itself also has power loss and temperature rise. So, you can ALWAYS expect a temperature rise in the cable, with a hot spot at the connections. The question is what temperature rise is permissible. IR guns that I have used are sensitive enough to show footsteps on carpeting, for about 20 seconds after the person has walked by, even with shoes on. So, dialing up the scale factors to very sensitive settings should be done with caution. THe danger point is the softening temperature, or Tg of a rigid plastic and the melting point of the flexible plastic. This precedes further destruction of the assembly.
Has anyone using SmartPlug 30 amp 50’ cords experienced problems with the marina power stand plugs. As I understand the SmartPlug at the marina end still uses the twist lock 80 year old design but with stainless steel contacts. My experience has been the marina power station plugs wear out and burn the plug contacts, maybe because of wear and tear, weather, etc.
diver dave
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Going with SS contacts has interesting consequences. Stainless is not a common high current conductor. Why? Because it has about 40x more resistance than electrical copper. And, that doesn’t account for surface passivation, that will climb that even higher, much higher. So, in a non corrosive world, materials like phosphor bronze, yellow brass and beryllium copper are used for contacts. That is the base metal. Platings include alloys of silver.
Now, you throw in corrosion factors, and fatigue life of repeated contact mating cycles, and you will find this to be a challenging design.
Now, you throw in corrosion factors, and fatigue life of repeated contact mating cycles, and you will find this to be a challenging design.
I agree, but SmartPlug says there plug contacts give more contact surface than twist lock types. Of course the straight contact design is only on the boat end. I would guess they over come the stainless steels added resistance by having more contact area.
Another question is the SmartPlug cord coils into a smaller size ? is that because the insulation jacket on the cord is thinner ? I would think 30 amp 50’ is still #10 wire.
Another question is the SmartPlug cord coils into a smaller size ? is that because the insulation jacket on the cord is thinner ? I would think 30 amp 50’ is still #10 wire.
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GoneFarrell
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dd, that is good info IMHO, thanks!
I did "spring house cleaning" on my cord connectors, boat receptacles, major loads, looked at all the pins, bright light/vacuum into the sockets. All looking good, clean with a brass brush/toothbrush and back in service.
The one thing I did find and needed serious attention was not the wiring or connectors, but the 1500 watt electric cabin heater. It was choked with dust and required a major cleaning down to/through the shaded pole motor. Now it runs like new and is a no-worry part of the boat again.
I would encourage users to inspect their electrical cabin heaters that have been running all winter for dust and dirt load, at least blow the things out with compressed air or vacuum. Coffee makers too, I've seen those start cooking themselves more than the coffee!
When I got this boat I bought 2 used portable cabin heaters. I had to completely disassemble & clean both of them of dust/dirt load to get them to work properly.
I did "spring house cleaning" on my cord connectors, boat receptacles, major loads, looked at all the pins, bright light/vacuum into the sockets. All looking good, clean with a brass brush/toothbrush and back in service.
The one thing I did find and needed serious attention was not the wiring or connectors, but the 1500 watt electric cabin heater. It was choked with dust and required a major cleaning down to/through the shaded pole motor. Now it runs like new and is a no-worry part of the boat again.
I would encourage users to inspect their electrical cabin heaters that have been running all winter for dust and dirt load, at least blow the things out with compressed air or vacuum. Coffee makers too, I've seen those start cooking themselves more than the coffee!
When I got this boat I bought 2 used portable cabin heaters. I had to completely disassemble & clean both of them of dust/dirt load to get them to work properly.
Northern Spy
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The pins are not stainless steel. They are nickel plated brass. Just like Blue Sea components.
From their website: https://smartplug.com/resources/faq/
"What materials are used in the SmartPlug?
All external metals are highly polished Marine-Grade 316 Stainless Steel, the electrical pins are nickel-plated brass for maximum conductivity, and plastics are UV and heat resistant resins made right here in the USA. And last but not least the internal electrics are fully encased in thermal epoxy making them 100% weatherproof."
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