Grounded Outlets?

[hcazrat]

Wondering if anyone knows whether or not the Emerald Princess has grounded electrical outlets in the rooms and if so, whether an earthing half sheet would be allowed. I'm doing some research for a friend who uses one for mobility issues who will be cruising in a couple of months. Thanks.

[redtogo]

Hummm, don't know. Can you truly ground an outlet on a ship?

 

The ship I am sure has a surge protector, of sorts, to protect their equipment and TVs, etc.

 

Maybe we will have an electrician answer.

[tserface]

I'm sure they didn't drive a stake into the ground and you wouldn't be able to use that feature unless you have a really long cord, but the outlets near our desk on the Star Princess have three prong receptacles and the ground works. They likely ground it to something metal like we did in the old days with house electrical upgrades :)

 

I've never used one of these devices specifically so I don't know if you'd get the same effect as on land.

 

Tom

 

Wondering if anyone knows whether or not the Emerald Princess has grounded electrical outlets in the rooms and if so, whether an earthing half sheet would be allowed. I'm doing some research for a friend who uses one for mobility issues who will be cruising in a couple of months. Thanks.

[Dudleydog73]

Interestingly I had to google this product to see what it was. It states that the ship may very well be grounded as salt water seems to facilitate that, however I would be hesitant to plug anything like this into the outlets on the ship.

 

There have been reports that simple devices like surge protectors cause grounding fault indicators on the ship's control equipment and they will come to investigate. This I would imagine would cause even more of a ground fault than a surge protector would, but I have no first hand knowledge.

[chengkp75]

Wondering if anyone knows whether or not the Emerald Princess has grounded electrical outlets in the rooms and if so, whether an earthing half sheet would be allowed. I'm doing some research for a friend who uses one for mobility issues who will be cruising in a couple of months. Thanks.

 

I'll admit, I had to look up what you were asking about. I still don't know the benefits this is supposed to give, so I really can't answer your question fully. The outlets are three prong, but the ship uses a "floating" ground, where the wiring ground is all connected together but not really "grounded" to the earth. Your house has not only the ground wire, but the neutral wire (the larger of the two flat blades) connected to the copper post driven in the ground. So there is current running in the neutral wire that is at the same potential as the ground wire.

 

A ship would have problems with this set up, as the steel hull is the ground, and any current flowing in the hull would create a battery using the sea water as electrolyte and cause corrosion of the hull. Therefore, both the hot wire and the neutral wire in a ship's 110v system are above ground. This is why surge protector power strips cause problems onboard, and are more likely to be confiscated than cheaper non-surge protector power strips.

 

If the benefit of the earthing half sheet is derived from being earthed to ground, I'm not sure there will be any benefit. Okay, looked a little further into the benefits and requirements of earthing. Not sure that there will be any benefits, but I don't understand it enough to say for sure, but the sheet will definitely not be at "earth" potential.

 

Apologize if I was too technical, but this is a bit of a strange situation, and maybe my info can help inform someone who knows more about "earthing".

Edited October 15, 2014 by chengkp75

[satxdiver]

The ship's electrical outlets are grounded both large prong and the round one are tied to the ship's ground which is not tied to the metal hull. An earth ground is not needed since the generators that crate the power are aboard the ship. So the generator ground and the various grounded outlets are all tied together on a common bus. Their electrical system can sense current on the case ground (little round prong) and take appropriate actions. This is what GFI/GCFI does in your home.

 

The reason earth ground is not needed on the ship and is needed on land is that the land based generation equipment is tied to earth ground. Your home therefore has to be tied to earth ground as well so that both of you are using the same reference point. If your home is not tied to ground, then your home is "floating" meaning the power in your home is no longer referenced to the same point the electrical generation equipment is using. What may happen is that the voltage that you are getting may be more or less and can change depending on conditions over time.

[Essiesmom]

Emerald Princess A724: Outlets at desk

Outlet behind TV is the same, and they are the same as on other Princess ships. EM

[chengkp75]

The ship's electrical outlets are grounded both large prong and the round one are tied to the ship's ground which is not tied to the metal hull. An earth ground is not needed since the generators that crate the power are aboard the ship. So the generator ground and the various grounded outlets are all tied together on a common bus. Their electrical system can sense current on the case ground (little round prong) and take appropriate actions. This is what GFI/GCFI does in your home.

 

The reason earth ground is not needed on the ship and is needed on land is that the land based generation equipment is tied to earth ground. Your home therefore has to be tied to earth ground as well so that both of you are using the same reference point. If your home is not tied to ground, then your home is "floating" meaning the power in your home is no longer referenced to the same point the electrical generation equipment is using. What may happen is that the voltage that you are getting may be more or less and can change depending on conditions over time.

 

Pretty close. A GFCI measures the current in the hot wire and the neutral wire, and trips whenever there is an imbalance (meaning current is flowing in the ground wire), but does not sense current in the ground.

 

The ship's power is generally "wye" connected, which means that instead of 120v between the hot wire and ground, and zero volts between the neutral and ground, there is 60v between both the hot and "neutral" wires and ground. Marine wiring does not really use a neutral wire in the sense that land wiring does.

[satxdiver]

I was trying to keep it simple and tell them why a ground rod driven into the ground is not needed or why the hull does not enter into it etc. I doubt many on here know why a wye or delta connection is used and how it works or even care for that matter. My description may have been a bit too simple but hopefully got the point across.

[chengkp75]

I was trying to keep it simple and tell them why a ground rod driven into the ground is not needed or why the hull does not enter into it etc. I doubt many on here know why a wye or delta connection is used and how it works or even care for that matter. My description may have been a bit too simple but hopefully got the point across.

 

Yeah, you were getting the point a bit better than I was. I was sort of stuck on the concept of earthing yourself to promote health, and thinking whether or not the ship's systems would do what was necessary. Still don't know.

[beg3yrs]

Chengkp75 and Saxtdiver, y'all gave great descriptions of the grounding systems. Even with my BSEE and MSEE though (fell asleep in power classes mostly) it took me a while to wrap my head around your descriptions. However, as I (and Tony the Tiger) said, they're great.

 

Now we're talking about earthing half sheets and if they'll do the job while on a ship. Here's an informative link: http://www.skepticblog.org/2010/08/12/are-you-a-grounded-person/

 

My guess is that while on a ship, OP's friend should not bother with a sheet but just keep one bare foot on the floor while sleeping. ;)

[Kartgv]

...My guess is that while on a ship, OP's friend should not bother with a sheet but just keep one bare foot on the floor while sleeping. ;)

 

After all the technical details, finally something I can relate to! The old college remedy for "too much to drink/room spinning"!

[PenguinLife]

If what has been described above is true I would not try it since there is a chance that under a fault condition the ground plug could be at a higher voltage potential than the hull. Therefore there could be a chance of electrical shock if you were to touch the sheet while it is plugged into the "grounded" outlet and anything else metal on the ship at the same time.

[chengkp75]

If what has been described above is true I would not try it since there is a chance that under a fault condition the ground plug could be at a higher voltage potential than the hull. Therefore there could be a chance of electrical shock if you were to touch the sheet while it is plugged into the "grounded" outlet and anything else metal on the ship at the same time.

 

No more so than any other electrical device. I checked some more sites, and the wiring in the sheet, while it does plug into a 3 prong outlet, only connects to the ground prong. There is no connection to the two current carrying conductors. They provide you with an "outlet checker" which is a device that tells you whether or not the 3 prongs of the outlet are wired correctly, to protect you from accidentally connecting the sheet to a hot conductor. While the ship's ground connection is not connected to the hull, there is virtually no voltage difference (a few millivolts) between them. There are circuits on the ship that detect whenever there is current flow between the hot conductors and the hull, which is why surge protectors cause problems.

 

I also see that the sheets come with an earthing rod to stick into the ground if an outlet is not handy. You could tape this to the steel cabin walls to see if this provides the necessary benefits.

[chengkp75]

Chengkp75 and Saxtdiver, y'all gave great descriptions of the grounding systems. Even with my BSEE and MSEE though (fell asleep in power classes mostly) it took me a while to wrap my head around your descriptions. However, as I (and Tony the Tiger) said, they're great.

 

My guess is that while on a ship, OP's friend should not bother with a sheet but just keep one bare foot on the floor while sleeping. ;)

 

Yes, I unfortunately tend to get a little technical. There are many things onboard ships that are far different from what most folks are used to ashore, from firefighting techniques to electrical systems, water systems, and food safety, so I try to explain the differences, and sometimes I even confuse myself. :p

[thinfool]

I'm doing some research for a friend who uses one for mobility issues who will be cruising in a couple of months. Thanks.

 

Interesting. Can you elaborate as to the relationship between an earthing device and mobility?

[chengkp75]

Interesting. Can you elaborate as to the relationship between an earthing device and mobility?

 

From the little research I've done yesterday, it would appear that it is mainly for joint pain relief. First I've ever heard of it, though.

Edited October 16, 2014 by chengkp75

[beg3yrs]

Yes, I unfortunately tend to get a little technical. There are many things onboard ships that are far different from what most folks are used to ashore, from firefighting techniques to electrical systems, water systems, and food safety, so I try to explain the differences, and sometimes I even confuse myself. :p

 

Yes, and the techno-geek in me loves to read your posts. Thanks so much for taking the time.

[hcazrat]

Thank you all for your responses. I won't even pretend that I understood much of it, but got enough to know you answered my question.

[MandD]

Wondering if anyone knows whether or not the Emerald Princess has grounded electrical outlets in the rooms and if so, whether an earthing half sheet would be allowed. I'm doing some research for a friend who uses one for mobility issues who will be cruising in a couple of months. Thanks.

 

The earthling sheets come with an outlet checker. Plug it into an outlet and it will indicate if there is a proper ground.

 

Also from the earthling.com web site:

Q. Can you connect an Earthing sheet to the electric outlet on a cruise ship?


A. You may want to check with the cruise company first. It is likely that a cruise ship would be well grounded and the use of in-cabin outlet grounds should work well.

[chengkp75]

The earthling sheets come with an outlet checker. Plug it into an outlet and it will indicate if there is a proper ground.

 

Also from the earthling.com web site:

Q. Can you connect an Earthing sheet to the electric outlet on a cruise ship?


A. You may want to check with the cruise company first. It is likely that a cruise ship would be well grounded and the use of in-cabin outlet grounds should work well.

 

The outlet checker only tells whether or not the hot, neutral, and ground wires are connected to the proper holes in the outlet. It will not tell if there is a "proper ground" (i.e. zero ohms to ground).

[thinfool]

Chengp...

 

I am a Master Electrician and have been following this thread closely. Some of it is amusing and some is very informative.

 

So I would ask...the 120 volt power onboard....is it derived from a transformer that is similar to one on land, or is it a particular configuration designed for marine use?

 

IOW, on land the voltage to ground/neutral is 120volts. From an earlier comment I got the idea that on a ship a center-tapped transformer, 60 volts on each side of a grounded center tap is used.

Edited October 16, 2014 by thinfool

[scott4020]

If I could come up with an idea like that to separate the gullible from their money I would spend a lot of time in the owners suite!

[chengkp75]

Chengp...

 

I am a Master Electrician and have been following this thread closely. Some of it is amusing and some is very informative.

 

So I would ask...the 120 volt power onboard....is it derived from a transformer that is similar to one on land, or is it a particular configuration designed for marine use?

 

IOW, on land the voltage to ground/neutral is 120volts. From an earlier comment I got the idea that on a ship a center-tapped transformer, 60 volts on each side of a grounded center tap is used.

 

Yes, the 220/110 transformer is a wye connected (center tap) transformer.

[scott4020]

Yes, the 220/110 transformer is a wye connected (center tap) transformer.

 

So how would the outlet checker they provide read with this type of wiring?

 

Now you guys got me wanting to bring my Fluke on a cruise :)