3rd Step Test Sudy Guide

Question 1

Why do we have concentric around UG primary cable?

Answer 1

They protect the conductor by evenly distributing the electrical field around the conductor.

Question 2

What information needs to be on a UG primary cable tag?

Answer 2

1. Adjacent sectionalizing device position.
2. Adjacent sectionalizing device number.
3. Adjacent sectionalizing structure number.
4. Next adjacent structure number. (Thru structure)
5. Footage.
   6 direction.
6. Voltage.

Question 3

What information needs to be on an UG secondary cable tag?

Answer 3

1. Structure number.
2. Distance to structure.
3. Direction to structure.
4. Voltage.

Question 4

What is PILC?

Answer 4

Paper insulated lead cable.

Question 5

What are some factors that can make pulling cable difficult?

Answer 5

Clogged duct
Water logged duct
Sweeps and bends
Deteriorated duct
Pulling speed

Question 6

What’s the minimum SWEEP radius for all size conduits?

Answer 6

12 1/2 feet

Question 7

What’s the minimum BEND radius for conduit?

Answer 7

Varies from 36 to 60 inches, based on conduit size.

Question 8

How do you calculate straight pull length and pulling tension.

Answer 8

Take the straight pull length and multiple it by the equivalent footage of the sweep or bend, witch can be found in a chart in the DDS. Then take that number and the next straight pull length and add them together. And repeat as more bends or straight pulls occur.

Question 9

What’s the average normal pulling speed?

Answer 9

10 to 50 feet per minute.

Question 10

What are Operating bulletins?
Safety bulletins?
Hotline bulletins?

Answer 10

• Better work practices.
• Advance notification of a change to a manual.
• Close call.

*

Question 11

What are the approved methods of under ground grounding?

Answer 11

• Underground equipotential bracket grounding
• Underground bracket grounding
• underground isolation

Question 12

How is underground equipotential bracket grounding achieved?

Answer 12

By applying a set of grounds all phases between the work location and each source with a EPZ created at the work location.

Maintaining the concentric is imperative.

Preferred method.

Question 13

How is underground bracket grounding achieved?

Answer 13

By applying a set of grounds between the work site and each isolated source.

Question 14

What are the four underground grounding schemes?

Answer 14

• Cluster
• Parallel
• Balanced
• Unbalanced.

Question 15

What are the 4 conditions required to create a possible ferroresonance condition?.

Answer 15

1. Transformer connected with a phase to phase connection
2. Phases are energized or de-energized one phase at a time.
3. Length of cable run is greater than critical cable length in the chart in table 2-7 and 2-6 in DDS-2
4. Secondary load is insignificant compared to the primary cable length.

Question 16

What 6 things must be verified when spiking UG cable?

Answer 16

1. Circuit maps
2. Cable tags
3. Amp check
4. Cable size
5. Direction of cable
6. Structure number

Question 17

What are four reasons that spiking may be required?

Answer 17

1. A dig in
2. Adding components (hammers or j bars)
3. Blown components
4. Lead cable

Question 18

When installing a hand hole what’s the typical depth of the layer of rock at the bottom of the hole?

Answer 18

3” minimum

** UGS HP 205-1

Question 19

What are pull boxes used for?

Answer 19

They are used for pulling and racking primary cable only.

Question 20

What are vault blowers and vent pipes installed for?

Answer 20

Controlling the atmosphere inside the vault.

Question 21

What does an atmospheric gas tester test for?

Answer 21

Oxygen deficiency

Explosive gas

Hydrogen sulfide

Carbon monoxide

**DOM TE-13 pg 6

Question 22

What are the basic steps for eliminating ferroresonance?

Answer 22

• Use gang operated switches
• De-energize or energize cable separate from transformer.
• Add secondary load DOM TR-8 figured 2 and 3 tell you how much you need.

Question 23

What describes a RAM a switch?

Answer 23

• All positions are can only be open or close
• They can be both manual or spring operated
• Rocker arm

Question 24

What describes a RAC Switch?

Answer 24

• First position is only open or closed
• All the other positions can be open, closed ( bus ), or tie ( to other positions )
• Can be manually or spring operated

Question 25

What describes a RAK Switch?

Answer 25

- First position is solid to the bus - Second position can only be open or close ( bus ) - All other positions can be open, closed ( bus ), or tie ( to another position )

Question 26

What the minimum depth for conventional underground conduits?

Answer 26

Conventional 30" CIC 45"

Question 27

What is the purpose of the concentric wires in underground cable?

Answer 27

They evenly distribute the electrical field around the conductor evenly distributing the stress on the cable.

Question 28

What's the maximum voltage load break elbows may be used?

Answer 28

16kv

Question 29

When operating load break elbows: A. How many qualified employees are required? B. From where are theses components operated? C. After they are disconnected what must be done immediately?

Answer 29

A. 2 qualified electrical workers B. Above ground and outside the structure C. They must be safe needed.

Question 30

What 6 things do properly applied grounds protect from?

Answer 30

- Backfeed - Static charge - Induction - energized overhead crossings - lightning - Accidental energizing.

Question 31

That's the WLL on the rescue sling on the gantry good for? What are the two configurations?

Answer 31

350 WLL Choker and bridal sling

Question 32

What is the purpose of the "tie" attitude for a switch position?

Answer 32

To separate the position from the bus and to the nest position instead.

Question 33

What are the two types of fuses?

Answer 33

Expulsion Current limiting

Question 34

What the difference between an expulsion type fuse and a current limiting fuse?

Answer 34

Expulsion: as the fuse arcs it burns the material surrounding the fuse and gases created by the arcing are channeled to blow out the arc and interrupt the current flow. Current limiting: they use special sand which upon the heat from the arc turns the sand to glass and becomes a high impedance path for fault current.