Unit 2 Personal and Equipment Protection

Question 1

• conductive path between earth and grounded object
  – Functions

Answer 1

Grounding

Question 2

Diverts dangerous currents to earth and activates protective devices (such as fuses and
circuit breakers) that shut down affected circuit

Answer 2

Personnel Safety

Question 3

– Prevents transient voltages and currents from reaching levels that could damage
equipment

Answer 3

• Equipment

Question 4

– Reduced by reducing voltage potential difference between equipment– Other measures such as shielding or filtering of local noise sources

Answer 4

Electrical Noise Reduction

Question 5

what are the 3 functions of grounding

Answer 5

Personnel safety, Equipment, Electrical noise reduction

Question 6

• Provides conductive path between earth and grounded facility
  Composed of three subsystems: earth electrode, fault protection, and
  signal reference

Answer 6

– Facility Ground System

Question 7

– Provides connection between earth and other subsystems in facility ground system;
consists of network of buried conductors such as ground rods, wires, water pipes

Answer 7

• Earth Electrode Subsystem

Question 8

Protects personnel and equipment from voltages caused by faults in electrical circuits
– Sometimes called “safety ground”
– Enable protective devices (e.g., fuses, circuit breakers, or ground-fault interrupters) to
operate when circuit fault occurs

Answer 8

• Fault Protection Subsystem

Question 9

– Establishes voltage reference for signal circuits and controls electrical noise and static in
a facility

Answer 9

• Signal Reference Subsystem

Question 10

what are the 3 subsystems of Facility Ground Systems

Answer 10

Earth Electrode Subsystem, Earth Electrode Subsystem, Signal Reference Subsystem

Question 11

Establishment of low-impedance path between two metal surfaces
“Bond” refers to both mechanical interface between joined
conductors and to bonding straps used to interconnect two
separate conductors

Answer 11

Bonding

Question 12

total opposition to current flow

Answer 12

• Impedance

Question 13

Types of bonding

Answer 13

• Direct, * Indirect

Question 14

Types of direct bonding

Answer 14

Direct permanent, Direct semi-permanent

Question 15

Direct Bonding

Answer 15

Formed by direct contact of the metal mating surfaces
» Expected to remain intact throughout the life of the system.

Question 16

Direct semi-permanent

Answer 16

» Metal surfaces rigidly held together by bolts, lock-washers, nuts, pins, clamps, or
other devices

Question 17

– Bonding straps used as interconnecting conductors when direct bonds are not practical
– Bonding straps are solid, braided, round, or flat metal conductors
– Example, signal reference bonds normally are indirect bonds

Answer 17

indirect Bonding

Question 18

Permanent direct bonds Techniques

Answer 18

– Made by welding, brazing, or silver soldering; best for providing mechanical strength and
low impendence
Example, exothermic welding is used to attach permanent direct bonds to earth
electrode subsystem

Question 19

Semi-permanent direct bonds Techniques

Answer 19

Metal surfaces rigidly held together by bolts, lock-washers, nuts, pins, clamps, or other
devices
– Contact areas must be clean and all protective coatings removed before bonding
– Must be protected against mechanical damage and corrosion
– Example, the signal reference subsystem normally uses direct, mechanical bonds (such
as crimps connectors and bolts)

Question 20

Bonding straps held in place by bolts, rivets, welding, or brazing
– Junction areas must be clean and protective coatings removed before bonding
– Mechanical bond must be mechanically strong
– Bonding strap must resist deterioration through looseness, stress or corrosion

Answer 20

• Indirect bonds Techniques

Question 21

• Corrosion introduces impedance in the bond
• Bonds between unlike metals (e.g., copper to steel, nickel to zinc)
  susceptible to corrosion
• Metal surfaces must be cleaned of all corrosion prior to bonding

Answer 21

Corrosion Control

Question 22

Sudden flow of electricity between two electrically charged objects

Answer 22

• Electrostatic Discharge

Question 23

• Caused by buildup of electrical charge (static electricity) on one surface
  suddenly transferred to another surface when they touch

Answer 23

• Electrostatic Discharge

Question 24

• Can be caused by friction between dissimilar materials, and transferred
  through difference of potential (difference of electrical potential between
  two points)

Answer 24

• Electrostatic Discharge

Question 25

Electrostatic Discharge Failures

Answer 25

Catastrophic, Intermittent, * Latent

Question 26

Total failure of the component(s) or electronic circuit(s)

Answer 26

Catastrophic

Question 27

– Irregular failures of the component(s)t or electronic circuit(s) – May cause minor damage to components within equipment

Answer 27

Intermittent

Question 28

– Delayed failure of the electronic component(s) or circuits(s)

Answer 28

Latent

Question 29

Be sure all personnel handling ESDS devices are grounded – Place all ESDS items on the workstation prior to opening – Ensure all hand tools are properly grounded – When removing ESDS from equipment, ensure you are the same potential as equipment

Answer 29

True, Handling Precautions

Question 30

– Do not remove ESDS items from packages until ready for use – Do not handle ESDS devices by their leads

Answer 30

True

Question 31

Security concerned with active and passive measures designed to prevent unauthorized access to any Air Force resource such as personnel, equipment, installations, material and documents

Question 32

– Security concerned with active and passive measures designed to prevent unauthorized access to any Air Force resource such as personnel, equipment, installations, material and documents

Answer 32

Physical Security

Question 33

Physical Security (cont.) – Requirements

Answer 33

– type and level of the information handled in a facility, – type of equipment – mission of the unit to which assigned – duty hours of the facility * Must be addressed and approved before construction of the facility

Question 34

– Requires some form of identification to get access – Examples would be base, medical pharmacy and server room in the communications squadron

Answer 34

* Control Area

Question 35

Restricted by both a special access badge and a “purpose” for being there – Examples of restricted areas would be flight line, security forces dog kennel, or a classified facility, like the National Security Agency (NSA)

Answer 35

* Restricted Area

Question 36

Personnel required to be accompanied by a companion – Example is classified burn or shred area; two people required in attendance while burning or shredding classified documents – Main role is know the requirements for unit of assignment and apply common sense security practices

Answer 36

No Lone Zone