Grounding

Question 1

How much fault duty is 4/0, 2/0, and 2str grounds good for?

Answer 1

4/0= 30,000

2/0= 18,000

2str= 9,000

Grounding Manuel page 3-3

Question 2

What are the 5 steps of testing conductors de-energized before applying grounds?

Answer 2

1. Clean location where you will be testing.
2. Put testing device on proper voltage range.
3. Before testing conductor de-energized make sure testing device is working by testing on an energized conductor first or by means of test switch on testing device.
4. Test each conductor/phase of the circuit de-energized before applying grounds.
5. After testing all conductors de-energized, retest testing device again.

Grounding manual page 3-14

Question 3

What are the 5 reasons we ground?

Answer 3

1. Accidental energizing
2. Induction
3. Static
4. Lighting
5. Backfeed.
6. Crossings

B.A.S.I.C

Question 4

What are 3 allowable ways to splice overhead primary conductors from the ground?

Answer 4

• use primary rubber gloves
• install a ground rod and ground on each side, within ten feet of work area.
• using a live line tool bond an EPZ mat to conductor at a single point.

Grounding manual pg 4-38

Question 5

When preforming overhead equipotential bracket grounding on main line with open source on each side of your work location, how must it be done?

Answer 5

• you must apply grounds on the open side of both open sources.
• and install a pole band and a shunt to one conductor at your work location.
• if your are within 1250’ of your bracket grounds you only need to shunt one conductor at your work location but if you are further than 1250’ you must shunt all conductors at work location.

Grounding manual pg 4-50

Question 6

When bracket grounding mainline what the maximum distance both sets of grounds can be from one another? What’s the maximum distance a set of the grounds can be from your working location?

Answer 6

2500’ max from one set of grounds to another.

1250’ max from your

Grounding manual pg 4-89

Question 7

List the overhead grounding schemes in order of preference.

Answer 7

1. Parallel
2. Balanced
3. Unbalanced

• overhead grounding manual 3.6.12

Question 8

Within how many feet from the sub are you required to use the station ground grid?

Answer 8

40 ft

OGM-3 pg 3-17

Question 9

How should de-energized wire down be handled?

Answer 9

Epz mats must be used or or the wire must be grounded to temp ground rods but can only be handled in rubber gloves

OGM step 6 ph 3-36

Question 10

When the hazard of induction is present is bracket grounding allowed?

Answer 10

No only epz grounding is allowed

Question 11

When do induction hazards exist?

Answer 11

Induction hazards exist when conductors (within minimum approach distance) are located within transmission/sub-transmission corridors, or support energized line(s) which are in parallel with the circuit being worked on for more than 600 feet.

Question 12

How do you inspect grounds before use?

Answer 12

Ground cable inspection

• check for cuts, nicks, or abrasions that may have gone all the way through insulation
• check for kinks that may have damaged cable strains.
• make sure ground cable is not flattened.
• check for swollen cable jacket or soft spots indicating internal corrosion or cable strand damage.
• verify GARP date is current.

Ground clamp inspection

• insure all components are in place and tight
• make sure threaded ferrule connections are tight
• insure ferrules and clamps are not cracked or broken.
• visually inspected crimped ferrule for broken strands or corrosion.
• inspect for corrosion on any threaded, hinged, or any other surface of clamp.

Grounding manual page 3-12