how the grounding is done in ships and aeroplane

ErnieM

Joined Apr 24, 2011
8,377
Sorry for the flippant answers Rohit, and welcome to the forum.

Obviously you cannot ground an aircraft when it is in the air, but it is important to keep the frame and such grounded when it is on the ground and being refueled. All you need is a cable and a clip. During construction the pieces of metal that make the air frame, and even instruments and other equipment is tightly connected electrically (or bonded) in case there is a large static build up or even a lighning strike: by bonding the metal together there is no way for a significant voltage to build up and damage people or equipment.

A metal hulled ship at sea is grounded by the huge piece of metal (the hull) sitting in the conductive fluid (seawater).

Small craft with fiberglass hulls will often have a grounding plate affixed to the bottom of the hull as a ground. This plate will (must!) be connected to any lightning rod to give the charge a known place to exit.
 

SLK001

Joined Nov 29, 2011
1,549
Just remember that ground is a potential. On a ship, the main ground is the steel hull. On an airplane, it will be the chassis. On both, every piece of equipment will have a common ground wire that eventually gets connected to the metal part of the hull/chassis.
 

atferrari

Joined Jan 6, 2004
4,764
Hola Rohit,

Aboard vessels, not all circuits have their neutral, electrically connected to the hull. The neutral is isolated. It is related to them being essential to safety / their voltage.

The excerpt below is from the .pdf I have attached to this post.

Electrical excerpt.png

Not as a seaman, I had the chance to do some work on board of two or three "wave piercing" ferries (fast ferries sailing at around 55 knots in open waters). Their hull is made of Aluminum and the builders took lot of pain to keep the electrical systems isolated from it to avoid corrosion due to undesired currents. They do have a quite sophisticated system to measure any leakage to the hull.

Vessels going to dry dock once they stop their generators, take power from the mains ashore which is connected through an specific location, usually going straight to the main switchboard in the Engine Room.

Not to confuse you but for tankers (oil - LPG), prior loading / discharging ashore or transferring to another vessel, they are "earthed" (their hull, I mean) simply to eliminate the chances of static buildup always before connecting any hose to the manifold.
 

Attachments

absf

Joined Dec 29, 2010
1,968
Hola Rohit,

Aboard vessels, not all circuits have their neutral, electrically connected to the hull. The neutral is isolated. It is related to them being essential to safety / their voltage.

Not as a seaman, I had the chance to do some work on board of two or three "wave piercing" ferries (fast ferries sailing at around 55 knots in open waters). Their hull is made of Aluminum and the builders took lot of pain to keep the electrical systems isolated from it to avoid corrosion due to undesired currents. They do have a quite sophisticated system to measure any leakage to the hull.
I should have read this 8 years ago. My friend asked me to design a simple earth-leak meter and told me it was for 24V DC system. Later he told me that it was used in a small ship sailing along the rivers.

The project was unsuccessful as the op-amp on the front end was always get toasted and I don't know the reason why. Now I know it was due to the AC voltage leak from the generator that was not neutral-grounded.

Allen
 

absf

Joined Dec 29, 2010
1,968
But I join AAC 2 years later; after the incidence.

I was hanging around in the google groups sci.electronics and comp.sys.spple2 then....:D

Allen
 
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