Dockhand plugged my 30A 120 into 30A 250

[a64pilot]

Originally Posted by TeddyDiver

DIY electricians alot around there?

No, it was a professionally installed and correct pedestal, possibly the plug had some wear I don't know but I managed to plug my 30 amp cord into a 50 amp receptacle .
It wasn't anyone's fault but my own, I incorrectly assumed that it wasn't possible to do, so I didn't get a flashlight or anything, just plugged it in.

Only reason I bring it up it to be sure and look, they are supposed to be idiot proof, but I suppose I'm a superior idiot cause I managed to make it fit.
Thankfully the Magnum freaked out and disconnected, or more likely didn't connect power and didn't pass it on.

[stormalong]

Originally Posted by Time2Go

You do know that when you pulled the plug on the boat
You were dancing with a live wire in your hand?
I always pull the cord off the pedestal (shore power) BEFORE
disconnecting the boat.
Just Sayin
Cheers
Neil

That is precisely why the hot side of power cords are always female. To get electrocuted you would have to insert something metal into the plug. I connect the shore side of of my cord before the boat side regularly and have never had a problem in over 40 years.

[Cadence]

Originally Posted by HopCar

I just don’t see how it’s possible to plug a 30 amp 120V cord into a 250 volt outlet. The plugs are completely different to prevent just that. The wiring on the dock must be really screwed up.

I'm with you. The only other thing might be a meter failure. I like analog meters.

[masonc]

Originally Posted by jbinbi

Looked at instruments 30 sec after he plugged me and to my horror noticed it was reading 250 V. Shut down my ac and pulled the plug out of the back of my boat.

That's not possible, the only source of 240V would be a NEMA SS2-50R receptacle. A NEMA L6-30P can't plug into that, unless you have some screwball receptacles. If you do, don't allow anyone to plug anything in without checking the voltage with a meter. It may be that the marina choose to use L6-30 for both 120V and 240V but that illegal and highly dangerous, I'd be calling the electrical inspectorate on that one.

[phorvati]

If he did somehow plug it into 240V, things might not be that bad. If you did have an appliances ON at the time, and exposed to 240V there is a very good reason why nothing smoked. I know from designing various UL safety devices that many (if not all) UL standards require appliance/device to pass an Overvoltage test without blowing up, or otherwise creating an unsafe condition. This means that a 120V rated appliance is plugged into 240V for long enough time to establish thermal equilibrium. I think there is a cap of 7 hours or so. Device is draped with a cheese cloth which would easily stain or catch on fire.

Now I would not trust crap coming out of china with a UL label on this. We test competitors products all the time and find them to fail various UL tests. Some fail in rather spectacular fashion behind a 1/2" lexan box.

The complicated thing with the overvoltage test is that while 120V appliance is turned on, it could get damaged, and as long as it fails in a safe way that would still be a pass.

So if appliance has a UL label, and was turned on you might be all right. But things might stop working prematurely.

[smac999]

Originally Posted by stormalong

That is precisely why the hot side of power cords are always female. To get electrocuted you would have to insert something metal into the plug..

or drop it into the water...

[S/V Illusion]

Originally Posted by HopCar

I just don’t see how it’s possible to plug a 30 amp 120V cord into a 250 volt outlet. The plugs are completely different to prevent just that. The wiring on the dock must be really screwed up.

I suspect you are correct -it is impossible.

[Nicholson58]

Originally Posted by wsmurdoch

What style of plug was plugged into what style of socket?

These are the common NMEA plugs and sockets used in marinas in the US.


Was there a mismatch of plugs and sockets or was there a wiring mistake in the marina or on the boat?

good pictograph. I have never seen a 250 volt 30 amp and it’s not shown in the picture. I would be most worried about electronics, not AC wiring. Does your charger inverter auto switch to accommodate voltage?

Many marinas have a 250 split to feed two 120 volt 30 amp sockets. It’s possible this stand was mis wired to combine the 120 legs back together.

[Snore]

Originally Posted by a64pilot

——idiot proof——

Hmm, that is your problem. A memo was issued in 2014.

Due to advances in idiocy, the rating of ‘idiot proof’ has been retired. All items can now only earn a rating of ‘idiot resistant’.

Lesson learned check for wear on plugs and receptacles before plugging in!

[jbinbi]

Originally Posted by wsmurdoch

What style of plug was plugged into what style of socket?

These are the common NMEA plugs and sockets used in marinas in the US.


Was there a mismatch of plugs and sockets or was there a wiring mistake in the marina or on the boat?

here are pics of what the marina plugged me into.

[jbinbi]

This was in newport. Most boats on the dock between 75 and 200 feet. Most large boats have 200-400A service. This was a small converter box. As you can see, the plug is for 30A. I gave the dock guy my cord and said I have 30A.

I am VERY familiar with the picture of the different style plugs and until this event, didn't think there existed a 30A 120 male plug orientation that would go into anything but a 20 or 30 A 120V. Clearly this dock had a 30A 250V outlet that used a standard 30A plug.

I am assuming that this was a split 240V breaker panel like in a house, with 120 on each side?

[valhalla360]

If you zoom in, the outlet is rated at 250v and based on your experience is wired that way.

But that is not the standard 240v marine outlet. Makes you wonder how many people have had issues but just never tracked it to the outlet.

[masonc]

Originally Posted by jbinbi

This was in newport. Most boats on the dock between 75 and 200 feet. Most large boats have 200-400A service. This was a small converter box. As you can see, the plug is for 30A. I gave the dock guy my cord and said I have 30A.

I am VERY familiar with the picture of the different style plugs and until this event, didn't think there existed a 30A 120 male plug orientation that would go into anything but a 20 or 30 A 120V. Clearly this dock had a 30A 250V outlet that used a standard 30A plug.

I am assuming that this was a split 240V breaker panel like in a house, with 120 on each side?

That is an L6-30, a 30a 240v outlet. It would not have a neutral, just a ground. Your idiot dockhand forced the L5-30 plug into it by spreading the prongs, not easy to do. I have never seen anyone manage to get that done.
I can't imagine why the marina would provide an L6-30, there's no neutra in that connectorl. A boat would need a balancing transformer to derive a neutral, and it would be floating, not referenced to ground, so there would be a PD to ground. ABCY does not allow ground bonding onboard. If the marina wants to provide 240/120, an SS2-50p is available for that. I do not believe that connector is allowed in a marina.

[wsmurdoch]

Yes, it looks to be a L6-30 Nema receptical.

[jbinbi]

Originally Posted by masonc

That is an L6-30, a 30a 240v outlet. It would not have a neutral, just a ground. Your idiot dockhand forced the L5-30 plug into it by spreading the prongs, not easy to do. I have never seen anyone manage to get that done.
I can't imagine why the marina would provide an L6-30, there's no neutra in that connectorl. A boat would need a balancing transformer to derive a neutral, and it would be floating, not referenced to ground, so there would be a PD to ground. ABCY does not allow ground bonding onboard. If the marina wants to provide 240/120, an SS2-50p is available for that. I do not believe that connector is allowed in a marina.

Thanks for the input. Actually, after he plugged me in, he said, "Your pins were bent a bit, I had to spread them out".

After he plugged me in, on my panel I turned on the charger/AC outlets/Water heater. I had nothing in the outlets. I looked at the panel a few seconds later and saw the V at 240 and red light on indicating reverse pol. So I shut down all breakers and pulled out the plug and told him to do the same. Went to look at the recepticle on the dock and saw that it was 250 and was perplexed as I only knew 50A/240V and know those to have a different set of blades, you can't get them into the 30A and vice versa. I will have to look at the blades to see if they are damaged. Thanks again.