GB2390692A - Faulty earth bonding system detector - Google Patents

Abstract

A device suitable for detecting a broken or damaged wire or a loose connection in an electrical circuit connection system is described. A multimeter is used to check the impedance of an earth bonding system and that it is in a serviceable condition. An indication needle and a red light on the multimeter may be used to indicate if the impedance of the system is high. A high impedance may indicate that the bonding system is faulty or that the energy level of the battery powering the multimeter is low. The device may be used to test the continuity of an earth bonding circuit for bonding an aircraft to earth potential during loading or unloading of fuel. This is to equalise voltage potentials between the aircraft and fuel delivery system to avoid the risk of sparks occurring.

Description

EL: 97246497

=FAX: +973 - 720200

_ "')))Mobile: +9739479393 Tartan Be lleHln' E _=,_,2390692

BONDING SYSTEM FAULT FINDER (B.S.F.F.)

INTRODUCTION

The movement of hydrocarbon liquid by pumping, mixing, filtration, or pouring causes the generation of an electrostatic charge. If enough charge has accumulated, a spark discharge may occur Whether or not the charge accumulates to a sparking potential depends on: The severity of the electrostatic generation mechanism.

À Conductivity of the liquid.

À Paths available for the charge to leak off or recombine with opposite charges. DEFINITION

Grounding is defined as the electrical circuit connection made between a unit of equipment and the earth surface. Grounding is used to mnize any electrical potential differences between the equipment and the ground.

Bonding is defined as the electrical circuit connection made between two units of equipment. It is used to minimize any electrical potential differential differences between them e.g. between quelling vehicle and aircraft.

REQUIREMENT

Grounding or bonding of certain equipment particularly between quelling vehicle and aircraft is necessary to safeguard personnel and equipment/aircraD against possible dangerous effects of faulty electrical facilities, lighting, or static electricity (See Attachment FIG.2).

All installations and operations, which are exposed to these electrical hazards, must be adequately protected.

Any static charges generated on aircraft or in equipment may be caused by atmospheric conditions or aviation product movements.

PREVENTION OF ELECTROSTATIC GENERATION

Ignition hazards Dom electrostatic sparks can be eliminated by controlling: À Electrostatic charge generation.

À Accumulation or discharge of electrostatic charge.

À Vapour - air mixture in areas where electrostatic spark discharges may occur. May/2001

GEL: +97246497

FAX: +973 - 720200

J Am_) Mobile: +979479393 _k E-Mail: al' redha43@}hotmar1 cam a 1. D ':F" D " 1bTó C! A - r =1 - The references given below are for understanding of how to prevent electrostatic generation/ignition: À NEPA-77 "Static Electricity" - National Fire Protection Association (USA).

À ASTM D4865 Standard Guide for Generation and Dissipation of Static Electncity in Petroleum Fuel System.

BONDING SYSTEM FUALT FINDING (B.S.F.F)

A. What is (B.S.F.F!? A. 1. It is a device to f nd any fault in the bonding system, from bonding reel mounting point to the bonding wire crocodile clip.

A.2. The device powered by 1.5Vx2 cells.

B. DESCRIPTION OF (B.S.F.F) (See Atrachmen' FIG 3)

B.1. B.S.F.F. consist ofa modified multimeter(A).

B.2. Bonding clip stowage point (C) (Normally f tied to allfuelling vehicle).

B. 3. A 3/d insulatorfiber O. Which isolate the bonding clip stowage point from the chassis.

C. How it works? (See Attachment -

C. 1. The main device is an ordinary multimeter Ohms (A) which has been modif ed to meet the objective and should he located in the Quelling cab (driver compartment) unclassif ed area (See FIG. 1) (Attachment FIGS 1 & 3).

C.2. A press "ON" release "OFF" button (B) has been added to the multimeter to meet this requirement Faultfinding).

C.3. One line connection (positive) is drawnfrom multimeter to the bonding clip stowage point (C).

C. 4. The other line (negative) connection is drawn from multimeter and connected to the vehicle chassis (L) or to bonding reel mounting point tD & E).

C. 5. Before use offuelling vehicle, the operator has to press the button (B) on multimeter to see the needle reading, which should read 0-102 Marc. simultaneously the red bulb on dial will light (K).

C. 6. If neither the needle reports any reading nor the bulb lights up this means: - Either the bonding wire is damaged (See FIG.4) (Attachment FIGS 2 & 4).

2 May/2001

At!. FUK:+973 - 720200 ))) Mobile:+973-g479393 11 - e ueRI E-Mail:all redha434ghotmalIcom OR - Bonding connections are loose.

OR - Some insulation has been developed between the chassis and bonding reel mounting area i.e. rust etc. OR - B.S.F.F. cells have been weaken and need replacement.

In file case of (C- 6) the vehicle is unsafe to be used on aircraft.

D. Why this device is required? D. 1. Experience revealed that the bonding wire get damaged (See FIG. 4) (Attachment FIGS. 2 & 4) un- noticeable because heavy equipment drive over it.

D.2. Connections on either side of bonding wire become poor /week.

D.3. The continuity between bonding wire reel and the spindle becomes weak and cannot maintain the continuity.

3 May/2001

Claims (1)

1. Claim plan M>. fits) This neater is desie<3L to trace any maltimetion

   within the bonding s;ysmm in the aircrad refueling vehcIe, as result of broken damaged wire or loose conrtion before commencement of my operation e.g. airet ah t efuelill defuellx,g, tFaDfer of products and or loading vehicle with product