When a SmartPlug goes for a swim

[Hydraulicjump]

Have to believe others have dealt with this and am seeking advice. About four days ago our Tempest weather station went offline, which means the boat has lost power (we are thousands of miles from the boat right now). A friend went down to the boat in Elliott Bay Marina in Seattle to find that the power cord with a SmartPlug connection was detached and under water. Notably, the loss in power coincides with when a boat cleaning service was there ( I know, first world problems…). He rinsed the connection with fresh water, dried it, plugged it back in, and flipped the tripped switch on the dockside power and everything seemed to be OK. He also wisely scrounged a line and secured the cord so that if it came loose it would not go into the water again (you all want this friend).

my question for others who use SmartPlug cords (this is an original from SmartPlug), should I lose trust in the cord since it soaked for at least four days in salt water or just go with it and hope for the best?

Thanks. This is trivial compared to the rest of the questions on this forum. But I gotta say, after nearly burning up my previous boat, I switched to the SmartPlug with enthusiasm.

 

[Comodave]

I put SmartPlugs on our last boat and also this boat. I put them on existing power cords on the last boat and this one I bought the cords from SmartPlug so they are molded in. Which do you have? If they are molded in plugs then water probably didn’t get inside the plug. If they were retrofit ends then water probably got inside the plug. If they were molded in plugs I would rinse them well and probably WD40 the contacts and give them a try and check them frequently for any sign of corrosion or heating.

 

[Hydraulicjump]

Thanks for the quick reply. This is the molded in kind that comes from SmartPlug. Good advice, including the WD40. Won’t be back to the boat for another week and a half, but will jump right on this.

 

[Comodave]

Just keep a close eye on it. Get a non contact temp gun and use it to check for overheating of the plug.

 

[High Wire]

My bet is it will fail and when you are not there again. Do you leave the air conditioning on while away? Food in the fridge? Inverter on standby? Concider the costs of replacing a dead house bank, spoiled food or a fire compared to a new replacement cord. Keep the old cord as a spare if you must or just cut the end off and give it away.

 

[Jeff F]

Keep the old cord as a spare if you must or just cut the end off and give it away.

I think I'd be comfortable cutting a foot or three off and installing a replacement plug. When I went to Smart plug I lopped off the scorched NEMA(?) plug and used the old cord.

But yeah, I wouldn't continue to rely on it as is.

 

[Bacchus]

I'm with Dave on this one... rinse well... dry out, WD40 and monitor.
If a problem you might consider a replacement plug and after connection fill with silicone sealant.

 

[STB]

How did everything look coming out of the water? One can clean things up a bit, but not "polish a turd". Once rinsed well, dried, and treated with whatever protectant you'd like, how do the connectors look? How does the cord going back from it feel? Still normal?

Plug it in. Does itnstill go in smoothly and lock? If so, load it up steadily. As you do, does the connector end or the wire back from it a few inches to a couple of feet get hotter than normal immediately or after being loaded for some time?

I'd suggest checking voltage at both sides, and you can, but sometimes.ifnthere is corrosion it won't show up without the load or with a pointy probe scratching into it.

If all of this is good, the cord is performing well, so I'd feel confident using it.

For an extra bonus, you can bring the cord in and let it cool off overnight, then straighten that end out on the dock in the sun. Fromnthere you can use a thermal camera to watch it as it heats up. If it is waterlogged, then waterlogged part may heat up more slowly than good part of the wire.

But, really, if it generally looks good and works good I'd call it good.

 

[diver dave]

Was it a GFCI trip at the dock? If not, that connector is suspect for sure.

 

[Hydraulicjump]

Thanks all for you posts. I will be on the boat next week and get to monitor this more closely, including evidence for scorching of the plug and the temperature when drawing lots of amps. My friend reported no adverse symptoms, but the only draw on it is the battery charger and the fridge. And most important, the GFCI did trip (good to know). As all of us on this forum know, redundancy is a sound strategy (let’s not debate one vs two engines), so I am leaning toward biting the bullet and getting a second factory SmartPlug cord. Less than one boat buck but still damned expensive.

 

[Turtle Blues]

I fill plug heads with dielectric grease. Would suggest it after rinsing and WD 40 as suggested above. Have dropped them in accidentally and not even tripped the breaker.
Monitor temperature when you plug it back in. If it starts heating up you will know quickly.

 

[utclmjmper]

If it ain't broke don't fix it..>>>Dan

 

[Turtle Blues]

Well that program would bankrupt would the Preventative Maintenance Industry

 

[sunchaser]

Is this a 50 amp cord? If so, load it up so both legs get a workout. That said, your best advice on this is Dan at Emerald Harbor Marine - on the shore near you.

 

[Nick F]

I think that there are two possible problems -

1 Increased contact resistance. As mentioned above, check for this using a temperature gun while under load.

2 Internal electrical leakage (from pin to pin). This should trip a GFCI breaker. However, the real test for this is a "Megger Test". Borrow a megger (or get an electrician to do this). The megger applies a high voltage (over 1000 volts) and detects if any current flows - it displays in ohms of resistance. You should have at least 100 megohms (one hundred million ohms) from pin to pin on a good connector. To improve low resistance, flush copiously with clean water (to remove any salt), then with alcohol (to remove the water) and dry with heat (hair dryer?) and leave overnight. Check the cord again after some time (weeks).

 

[C lectric]

I will second the MEGGER suggestion. I have one and used it a lot. Not for this particular purpose but often at work to figure out what the problem was.

A DMM cannot duplicate their effectiveness, good as they are.

 

[diver dave]

Sometimes called a “insulation resistance” tester. I bought one that had options for 500 and 1kV. Fluke makes a small handheld one.

 

[kchace]

If it were me I think I might continue to use it but monitor it more closely and perhaps get a spare plug to replace when/if it fails. I would assume at least a tiny amount of salt got in and will shorten its usable life.

Ken

 

[Comodave]

Maybe, maybe not. SmartPlug does seem to use quality products in making their stuff. Hopefully it will survive.

 

[O C Diver]

Fresh or saltwater?

If saltwater, I think you have to cut the cord back till you get clean copper (don't think shore power cords use tinned wire). Given the period of time in saltwater, I just don't see the contacts surviving long term. While it may be fine now, I don't want a fire starting on my boat one night while I'm onboard. What's your life worth?

Freshwater may be different, but still not worth my life.

Ted

 

[Bmarler]

having the plug in the water for four days would lead me to think that salt water would have entered the wire under the insulation. i haven't cut open one of their moulded ends to see how the wire ends are done, but it's hard for me to believe they're completely impervious. i'd think it will degrade slowly and become unusable, maybe heating up enough to ruin the shore power inlet as well.
too bad it happened in the first place, those ends have great locking mechanisms but you do need to make sure they're properly set, including the secondary lock that a lot of people don't bother with.

 

[Comodave]

I always set the top latch along with the side latches. Not sure how it could come off by itself. Maybe somebody messed with it???

 

[Bmarler]

I always set the top latch along with the side latches. Not sure how it could come off by itself. Maybe somebody messed with it???

i think it was mentioned that a cleaning service had been to the boat. presumably the cord was in the way and not re-installed correctly.

 

[Comodave]

Then I would let them buy a new power cord.

 

[SteveK]

Then I would let them buy a new power cord.

Now since they did not own up to to it, how can they be made to do that. If brought to their attention an honest person would remember yes I unplugged it, then did I plug it back in? Let me buy you a new cord.
Those were the days when owning it meant something.

 

[Comodave]

Then I would take my cleaning business elsewhere and tell everyone about it. I complement people when they do a good job and tell everyone. I also complain when I get bad service and tell everyone too. The OP still has some leverage if he wants to use it.

 

[CharlieJ]

The correct thing to do is to cut back to cord until you find bright, shiny copper. Then reinstall the SmartPlug. Not worth it to not do it right.

 

[Hydraulicjump]

First update on this. As mentioned earlier, a friend went down, rinsed and cleaned up the cord and plugged it in. I think at least 2/3 of you expected this: it ran fine, until it didn't, tripping the dockside breaker. So I bit the bullet, ordered a new one from Fisheries in Seattle ($345!). He picked it up for me (I am still in California) and all is working to spec. I had him feel the connections with his hand (too hard to tell him where the laser temp is) and everything was cool as could be.

I will get back to the boat next week and will, for my edification, take the female connector apart. If it has good visuals I will take post them here. I will also check the boatside connection for any arcing.

I appreciate everyone's input on this. So I think the answer to the title of this post is, if your SmartPlug takes a prolonged swim (remember, four days) it is toast. Either get a whole new cord (1/3 of a boat buck) or get a new connector (1/10 of a boat buck but not factory sealed) and start over again.

Now, as for the cleaning crew, I cannot definitively prove that they are the ones who left the plug in the water, even if the power went out on the day they were cleaning. So I have to give them the benefit of the doubt (they have apologized profusely). And I had my friend rig a short line to a stanchion so that even if the plug comes out or is left out it stays out of the salt water. Hey, maybe THAT is the useful takeaway from this saga.

Again, thanks for the input. I appreciate you all helping me crowdsourcing answers to my problems.

Jeff

 

[STB]

Out of curiosity, did the old cablenwarm up near either end underload? That's usually the predictor for me (other than visual).

 

[Hydraulicjump]

Regrettably, I was not there to test it and my friend did not report it to me. But if I see scorch marks on the connector I most certainly will have my answer.

Lucky me to have a friend to run down to the boat and check on it.