Quote:
Originally Posted by bobatkins
Original posted on 04-01-2019, 14:11:
I have an original 30A SmartPlug that I purchased several years ago that I am very happy with! Sure, the original plug wasn't as robust but SmartPlug has stood behind their product well beyond any warranty and provided me with replacement parts and an upgraded plug when my original one failed due to the less than robust strain relief design. I'm even more pleased with the new version which seems to be beefier in all respects with much better and more robust strain relief and screw terminals inside the plug.
My unit has the built-in thermal breaker on the inlet and I'm bummed to read that this safety device has been removed. That said, I understand the reasoning behind the ABYC rules against a self resetting breaker.
May I suggest considering a thermal breaker with a reset button inside the center of the inlet in between the pins. The plug could have a small recess in the center to allow the breaker pin to pop up. If the thermal breaker pops power would remain off. The user would need to unplug the shore power cord and would have a visual indicator inside the inlet to check as the possible cause for the loss of power. Pushing the breaker in would reset it and you would have ABYC compliance and I think an even better product. |
I ended up regretting the above post in a major way. On Feb 15th, 2020 I
lost my boat to an electrical fire. I had personally installed the Smartplug on my boat about 6.5 years earlier and the receptacle externally showed absolutely no signs of degradation. The image below of the receptacle was AFTER the fire and even though there was a conflagration behind it - whatever they made the middle part from didn't show any signs of
distress - essentially fire proof. Yes, the dockside shore power breaker blew. Yes, it was the latest GFI protection on new docks. But overload breakers don't protect against heat caused by a high resistance connection - they only blow when the circuit load exceeds the breaker's load limit. GFI breakers only work to protect against live to ground current leakage. Only a thermal breaker at the point of the heat source will protect against a high resistance connection and this was one of the primary reasons that 6.5 years earlier, I purchased the SmartPlug to replace my old 30A Marinco receptacle that had started showing signs of thermal damage.
Unfortunately the back of the SmartPlug receptacle is made from material that can and did melt. That flaming melted goo went down the AC wire and stopped at the PVC conduit carrying the DC wires and set it on fire - all buried inside the back of my boat behind the
engine panel and the rest as they say was
history... Right before the start of the pandemic lockdown I
lost the boat I had since new, had maintained like my aircraft and dearly loved.
The pictures and the fire investigation clearly show that the fire started behind the Smartplug. As an
engineer I wanted to know how a fire could start behind what was supposed to be a thermally protected receptacle! You be the judge of the X-ray
images.
Here are the pictures:
This is what the receptacle looked like
Post fire!
Here are the X-ray
images of the burned receptacle:
This is the receptacle from another boat that almost caught fire!!
You can clearly see that the X-rays show that there is a direct connection between the inside wires and the lugs on the Smartplug that go directly through the housing.
The last picture is that of another Smartplug (also about 6 years in service) from another boat where the owner happened to be on board when he smelt electrical smoke and disconnected the shore power before an inferno started. You can clearly see where the problem started.
Why, after about 6+ years did this happen?
Well - first of all it is clear that the thermal protection advertised for this receptacle failed to do its job.
But why the melted wire - as shown in the last picture? Because the Smartplug receptacle has nickel plated
steel lugs/pins, unlike the typical Marinco (round 30/50A) receptacles that use copper lugs/pins. The AC wire inside the boat is copper. Need I say more? In a
marine environment, the dissimilar metals between the nickel plated
steel and the copper wire setup galvanic
corrosion whereas this won't happen with the typical copper lug/pin Marinco receptacles.
Unlike the Marinco which shows evidence of failure/overheating in the form of externally visible discoloration of the plastic in the receptacle - giving warning of failure, the Smartplug conceals such failure from view - behind it and out of sight! For some reason the materials used on the backside of the receptacle are nowhere near as fireproof as the middle of it!
For the last year+ I have been so angry. I have blamed myself for not being able to put out the fire - I was nearby when it started but it was already too far along by the time I got to the boat. My attempt to put it out by fighting it down below landed me in the ER. Thankfully the fireboat arrived quickly and prevented the boat from burning to the waterline which also preserved the evidence of how the fire started. Total time of the fire was about 10-15 minutes and the boat was totalled - burned inside from stern to bow!
I never in a million years thought that I would need to remove the 4 screws that secured the receptacle to the boat to look behind it to check for any potential issues!!
4 f***ing screws and I would still have my boat... :-(
But I am seriously pissed off at SmartPlug because they set me up for a total false sense of
security - the very reason that I installed their f***ing receptacle in the first place - to protect against the possibility of exactly what happened - a shore fire induced electrical fire!!
Everyone one of these receptacles are ticking timebombs - they are ALL suffering galvanic
corrosion and likely most, if not all of them have no internal thermal protection as advertised. Who knows how many boats have been lost already!
I hope one day to find another boat and I will no longer take any chances - I plan to install a
stainless steel junction box behind the AC receptacle into which I will also install a real thermal breaker with visible external status/reset. If it ever goes - it will not reset automatically. I will carry the internal main copper AC wires inside a stainless flex conduit to the main AC breaker which I will also enclose in a
stainless steel junction box with its own thermal breaker. Exposed AC wire and connections are not allowed in any building.
Commercial buildings require steel junction boxes and conduit for all AC wires! Why is this same standard not applied to boats???
And I will make a point of inspecting the back side of the shore power receptacle annually for any signs of failure.
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