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ET1 U2 L2
How to verify proper grounding of electronic equipment
Question | Answer |
---|---|
What is the length and diameter of a typical grounding rod? | 10 feet long by 3/4 inch diameter |
Which ofthe following metals should NOT be used in the construction of down conductors? | Tin |
The metal framework of a building should have a resistance of less than _____ ohms? | 10 |
Which class of bonding involves welding of two pieces of metal together? | Class A |
DC resistance across bonding and grounding junctions shall NOT exceed _____ ohms? | .1 |
When installing an eath electrode subsystem, which wire color denotes the grounding conductor? | Green |
Which of the following references is NOT used when inspecting a fault protection subsytem? | Civil engineering manual |
To protect a structure, such as abuilding, vessel, mast, etc... from lightning damage; the grounding cable should be _____ AWG? | 0000 |
List the primary advantage of using a floating ground subsystem | Prevents noise from being coupled to signal circuits |
What is the recommended frequency range for a single-point ground configuration? | Up to 300Khz |
Which sybsystem should NOT be considered an option when developing the earth electrode subsystem? | A direct bond between two similar metals on top of the soil |
RF impedance across bonding and grounding junctions shall not exceed _____ ohms? | 25 |
Should zinc be used when grounding an electrode? | No |
If a lightning strike produces 220Kv approximately how much voltage will subsequent strikes produce? | 110Kv |
Does VHF use a signal reference grounding system? | No |
What class bond uses bolting or clamping? | Class B |
What class bond uses bridging using a cunductive strap? | Class C |
Measure the resistance every ____ months of the earth electrode subsystem | 12 |
electrode conductors may be | solid, stranded, insulated, covered, bare wires |
fault protection devices include | fuses, circuit breakers, ground fault sensors, ground fault circuit interrupters (GFCI) |
fault sensors do what? | monitor current |
GFCI does what? | monitor the current supplied from the source and are very sensitive. |
effects by lightning strike include | thermal, mechanical, electrical, conductor impedance, induced voltage |
air rterminal does what? | attracts lightning away from building |
air termainal mounting on a flat roof? | on the corner edges |
air terminal on a pitched roof | within two feet of redged ends |
air terminal mounting on a sloping roof | on corners and edges with terminals less tjan 24" are spaced at a max 20' apart; equal or greater than 24" in height spaced at a maximum 25 ft apart |
bends of down conductors | not less than 90 degrees or radius of 8 inches |