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7 comments
Participant

Join Date: Jul 2008
Posts: 1

Earthing in Aeroplane and Ship

07/02/2008 2:32 AM

Dear Sir,

I want to know how elctrical earthing provived in the aeroplanes and ship. and how it works.

With Regards

Sandeep dhiman

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Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain - possibly to become "South Scotland" or "Non-Caledonia" from September 2016. Kettle's on.
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Good Answers: 591
#1

Re: Earthing in Aeroplane and Ship

07/02/2008 7:55 AM

In the case of an aeroplane, the structure is likely to become charged during flight, particularly in atmospheric conditions adjacent to thunderstorms. Airport procedures include earthing the plane upon arrival, by attaching an earthing cable to the fitting provided on the aircraft. This conductor returns the aircraft to local earth potential and discharges any static, an important consideration prior to refuelling activities.

Ships do not require an earthing conductor per se, as the body of water in which they float is sufficiently conductive to enable a proper earth connection to be provided without supplementary conductors.

In both types of vehicle, the structure is considered a common earth ground for the purposes of protective circuit device operation within them.

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Participant

Join Date: Jul 2008
Posts: 2
#7
In reply to #1

Re: Earthing in Aeroplane and Ship

07/16/2008 4:53 AM

hey bro thanx so much for ur comment it was very helpful. if u could send me some more info or a link from where i can have the info ill be garteful to u. my email is akshayemonga@hotmail.com.

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Power-User

Join Date: May 2008
Posts: 232
Good Answers: 10
#2

Re: Earthing in Aeroplane and Ship

07/02/2008 11:43 PM

Earth and ground are not the same. If you consider ground as 0V, then all should make sense. Earthing the plane before/after take-off equalizes the ground potential between the plane ground and the earth ground point.

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Anonymous Poster
#3

Re: Earthing in Aeroplane and Ship

07/03/2008 7:46 AM

Airplanes have devices on the wings, stabilizers, rudder, elevators and ailerons, called STATIC WIGS that discharge the static electricity produced by the friction of the air during flight.

Wires attached to the landing gears come in contact with the ground upon landing and continue to produce a path for the static electricity. finally a wire is attached to the aircraft and ground, this is specially mandatory for fueling operations.

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Anonymous Poster
#6
In reply to #3

Re: Earthing in Aeroplane and Ship

07/06/2008 12:46 AM

my frnd.

Ur suggestion and statement is very clear . very nice it is. Normally how the flight will take off .wat s the principle behind this and how it works. my mail id is ktva361_eee@yahoo.co.in

Thank u

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Anonymous Poster
#4

Re: Earthing in Aeroplane and Ship

07/03/2008 8:31 AM

On ships we use what is called a floating ground. In the case of 440 3 phase, the supply is not bonded to the hull so there will be a capacitive ground and measuring from any phase to the hull will give ~270 VAC. Each phase is then monitored for ground.

The advantage of an ungrounded system is, especially in the case of a ship, if one phase becomes grounded it will not cause a fault that will disrupt the power to the circuit. For example, if A phase becomes grounded, voltage to ground from B and C will be 440 VAC, but the load will still see full voltage and the breaker will not trip. If one phase was bonded to the hull, a ground on one of the other phases would cause the breaker to trip.

This system does require monitoring and grounds should be cleared as soon as they appear on the system.

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Anonymous Poster
#5
In reply to #4

Re: Earthing in Aeroplane and Ship

07/03/2008 1:51 PM

The High Resistance Ground system is also being applied to industrial power systems nowadays. ( simply search the Internet for "High Resistance Ground ").

Most major electrical equipment manufacturer offer retrofit panels allowing you to convert solidly grounded systems to HRG.

They come with a built in pulser and fault locating facility.

It give you the ability to continue to operate even though you may have a solid phase to "ground" fault.

On the DC side , since ships and planes do have DC battery systems, the DC systems are not grounded but do have a ground fault monitor which will indicate a ground fault.

The reason for not grounding either positive or negative side of a DC system is the increased reliability it offers.

If a solid ground fault develops on one side , the ground fault monitor will give you an alarm or indication which alows you to troubleshoot and correct the problem before a second one develops on the other polarity which will result in a short circuit.

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