3Rd Step Self Study Guide

Front 1

1. What is a distribution tap line?

Back 1

A DTL is a distribution voltage line section that has a single source of supply, and can be

isolated by a device having no more than once source and one load terminal.

Unless that are connected to a generating facility of any kind cannot be considered a DTL.

CAUTION: It must be specifically noted that a circuit section cannot be corisidered a DTL

if the device used to energize the section is equipped with more than one source and one

load terminal

Reference: SOB 301 3.3.1

Front 2

What information is required on a cable tag?

Back 2

1. Adjacent sectionalizing device position

2. Adjacent sectionalizing device number

3. Adjacent sectionalizing structure number

4. Next adjacent structure number {through structure)

5. Footage to next adjacent structure

6. Direction to next adjacent structure

7. Operating voltage

Reference: DUG, lC 130.4.1

Front 3

What does a "qualified employe" mean?

Back 3

An ernployee ·who by reason of experierlce of instruction is familiar vJith the operation to

be performed and the hazards involved.

Reference: APM Definitions

Front 4

What does a "qualified electrical worker" mean?

Back 4

A qualified employee who, by reason of a minimum of two years training and experience

with exposed high-voltage circuits and equipment; and who has demonstrated by

performance, Is familiar with the work to be performed and the hazards involved.

Reference: APM Definitions

Front 5

What is the maximum depth of a trench that can be entered without shoring?

Back 5

5 feet

Front 6

How many pipe straps are required per 10-foot section of riser?

Back 6

3 straps

Front 7

How many unistruts or kick blocks are required per 10' section of riser?

Back 7

2 - Above the 8 foot level

Front 8

How soon should hazards be reported?

Back 8

Employees shall immediately report any defective tool, apparatus, equipment or other

hazards condition or work practice to the most available supervisor.

Reference: APM Policy P-18-A

Front 9

How often should high voltage rubber blankets be dielectrically tested/inspected?

Back 9

Rubber gloves, sleeves, blankets, used on high voltage (above 600 volts} conductors and

equipment shall be dielectrically tested at least once every six months and before being

placed into service when received from the manufacturer. This equipment shall be

marked with the date the dielectric test was conducted.

Reference: APM Rule 131.h

Front 10

What should be done when using rubber blankets on the ground?

Back 10

Rubber blankets, when used on the ground, shall be protected from physical damage and

moisture by means of tarpaulin, canvas or protective mat.

Reference: APM Rule 131.f

Front 11

What is the minimum amount of time to wait before entering an underground structure

when new cable has been energized for the first time?

Back 11

5 minutes.

Reference: APM Rule 303.c

Front 12

According to the APM, what shall be done prior to and after moving or bending any ln-

service cable?

Back 12

The cable shall be carefully inspected before and after moving.

Reference: APM Rule 307.a

Front 13

When will the automatic circuit recloser on an underground circuit being worked be

made non-automatic?

Back 13

1. Testing, grounding, cutting, spiking, repairing cable or components normally energized above 600 V.

2. Disassembling cable components normally energized above 600 V.

3. Installing or removing electrical or communication cable.

4. Relocating energized high-voltage underground cable or equipment.

5. Filtering or replacing oil on energized high voltage underground equipment.

6. Operating energized loadbreak components.

NOTE

In addition to the above requirements supervisors in charge may make automatic circuit reclosers non-automatic whenever they deem it necessary for the safety of the employees performing the work or may consult with their manager to determine if a line section or piece of equipment should be de-energized.

7. Immediately following a high-voltage failure.

Front 14

Why is it necessary to use a live-line voltage tester?

Back 14

To test normally energized parts of a circuit (as being de-energized).

Reference: APM 141.a

Front 15

What is a clearance?

Back 15

A clearance is the formal authorization, officially issued to a qualified person, at that

person's request, to work on an electric line or some piece of operating equipment which

is inherently too hazardous to work on while in service, and has been de-activated or de-

energized, in a prescribed manner and placed in a safe condition to be worked on.

Front 16

When distribution personnel work inside a station, who takes the clearance?

Back 16

Except as noted in paragraph d., the only person qualified to take a clearance for work

inside a station from an operator, shift supervisor, or station electrician on duty at that

station is defined as a person who has been designated as qua lifted by the division

manager (or his/her authorized representative) having jurisdiction.

Reference: APM Rule 707.c

Front 17

Define a compound fracture.

Back 17

Compound Fracture: ln a compound fracture, the bone is broken and there is a

connecting wound usually caused by the bone breaking through the skin.

Reference: APM Rule 1005.a.2

Front 18

What is the objective when administering first aid to a burn victim?

Back 18

The objective of the first aid responder attending a burn victim is to relieve pain, prevent

infection and treat for shock immediately.

Reference: APM Rule 1006.c

Front 19

What are the specific symptoms of a first-degree burn?

Back 19

• Mild to moderate pain.

• Redness or discoloration.

• Mild swelling.

• Skin warm to touch.

• Rapid healing and little, if any, scarring.

Reference: APM Rule 1006.b.1

Front 20

Can 600 A plug-in terminations and components be removed by hand if they have been

tested de-energized with a High Voltage Tester?

Back 20

live line tools are required for removing and installing plug in terminations except when

complying with applicable sections of Rule 306.

Reference: APM Rule 312.a

Front 21

. Prior to a normal vaul~ entry, for what is the structure's atmosphere tested?

Back 21

All structures shall be tested for oxygen (02), combustible gas (LEL}, hvdrogen sulfide

(H2S), and carbon monoxide (CO).

Front 22

. Prior to a normal vault entry, for what is the structure's atmosphere tested?

Back 22

All structures shall be tested for oxygen (02), combustible gas (LEL}, hydrogen sulfide

(H2S), and carbon monoxide (CO).

Front 23

An SF6 gas switch - inside a vault - is suspected to have catastrophicaliy failed. What i

additional atmospheric monitoring is required prior to entering this vault?

Back 23

Testing for suifur dioxide (502) is required where it is likely to exist. Sulfur dioxide may

exist if a piece of SF6 equipment has failed catastrophically. Reference: DOM, TE~13 2.1

Front 24

Is it permissible to pull cable with a cable grip near conductors energized at more than 300 volts? Expiain.

Back 24

Yes, when observing the following:

When installing or removing underground cable in proximity to exposed conductors energized above 300 volts, adequate precautions shall be taken to prevent accidental contact between the cable, or metallic pulling devices, and exposed energized conductors.

Reference: APM Rule 308.a

Front 25

What depth should a CIC riser extend below grade?

Back 25

CIC shall be instalied with a minimum cover of 45 inches in commercial and residential

areas.

Reference: DUG, Figure CR 120-1

Front 26

Between grade and 8-feet high, what is the minimum size and schedule that is used for riser construction?

Back 26

2Yz inches, schedule 80.

Reference: DUG, Figure CR 110-1

Front 27

When working in or around underground vaults, what protection must be taken at the entrance?

Back 27

Adequate barricades or standard railings shall be used, unless the opening is constantly attended.

Reference: APM Rule 302.b.3

Front 28

After de-energizing and before proceeding with the work on alt power supply cables normally energized in excess of 600 volts, where should all conductors be short- circuited and grounded?

Back 28

l. or

Between the place where the work is being done and each possible source of supply,

at the work location, or

as close as practicable to the source of supply.

2.

3.

Reference: APM Rule 306.c

Front 29

How many bushings do 25 kVA BURD transformers used for ferroresonance mitigation have?

1. 6.9 kV BURD

2. 9.5 kV BURD

Back 29

a) 3 bushings

b) 3 bushings

Reference: DUG, Figure TX 300-14

Front 30

What are the formulas used to calcurate full load amps on both single- and three-phase transformers?

Back 30

KVA times 1000 divided by voltage

KVA times 1000 divided by voltage time 1.73

Front 31

identify the four conditions required to create a potential for ferroresonance.

Four conditions are required to create a situation where ferroresonance might occur. Unless all four are present, ferroresonance will not occur. The four conditions are as follows:

Back 31

The transformer or bank has phase-to-phase primary connections, or a wye primary with an ungrounded neutral (floating 1,vye).

Phases are energized or de-energized one phase at a time.

Combined secondary load on the radial is insignificant compared to the primary cable lengths being switched.

!f the primary cable will be energized or de-energized one phase at a time; and the length of the cable is greater than or equal to the critical length as shown in Table 1 (Page 9), a ferroresonant condition may exist. Cable length is the total length (of the run, not the sum of al! phases) of all cable in the circuit being energized/de-energized and is

measured from the connection point to the end of the radial. Reference: DOM, TR-8 Attachment 1

Front 32

. A switch may be considered de-energized for switching only when what conditions exist?

Back 32

1. The switch contains only one circuit and is in a dead section of line as verified through

the Switching Center. \

2. Rules 309 b., c., d., e., f., and g. have been complied with. Reference: APM Rule 309.a

Front 33

A switch may be considered de-energized for switching only when what conditions exist?

Back 33

1. The switch contains only one circuit and is in a dead section of line as verified through

the Switching Center. \

2. Rules 309 b., c., d., e., f., and g. have been complied with. Reference: APM Rule 309.a

Front 34

With regard to ferroresonance, describe and contrast the terms "cable length" and "critical cable length.

Back 34

Cable length is the total length (not the sum of all phases) of al! cable being energized/de-energized, and is measured from the connection point to the end of the radial.

Critical cable length is the total iength per phase that is just enough to make ferroresonance a possibility when switched with unloaded transformers.

!f the primary cable being energized or de-energized one phase at a time is of length greater than or equal to the critical cable length, then a ferroresonant condition may exist

For multiple transformers being switched on a radial, the critical cable length is based on the total kVA being switched; for instance 150 kVA if switching three 50 kVA units.

Reference: DDS-2, 5, 13

Front 35

Name the four ways to eliminate ferrnresonance, including design considerations.

Back 35

Use phase-to-ground primary connections prevent ferroresonance. Energize/De-energize transformers and cables separately.

Use secondary load as a means to eliminate switches.

Sectionalize using gang-operated switches, when necessary.

Reference: 005-2 5.13 B

Front 36

Explain company policy concerning locking stations and enclosures.

Back 36

Ali stations and gates to switch structures containing energized high-voltage equipment shall be kept closed and locked at all times except when a qualified employee has such station or structure under observation.

Reference: APM Rule 103

Front 37

Explain how and when to address backfeed.

Back 37

Before contacting the high-voltage (rated in excess of 600 volts) side of a de-energized transformer(s}, or conductors connected thereto, all possible sources of backfeed shall be eliminated by disconnecting with fln opening (opening primary or secondary jumpers, fuses, primary switches, cutouts, etc.}, or by grounding and short circuiting the low or

high-voltage side. Reference: APM Rule 149.a

Front 38

What are the two types of materials used for vault covers? When would either be installed?

Back 38

Cast-iron is used for traffic loading. RPM is used for parkway loading. Reference: UGS, 400.11.2

Front 39

What are the characteristics of a 400-amp RAC switch?

Back 39

The RAC switch will have four or more ways.

The RAC switch may be manually operated or spring operated. !t should be noted that the far left position has on!y two attitudes {Open-Bus) while the remaining positions have three attitudes {Tie-Open-Bus). This creates the capability of electrically tying two adjacent positions together without using the bus

Reference: DOM, SW<3 Attachment l

Front 40

According to the APM, when are blocking devices required during switching?

Back 40

1f switching on a "RAC" type switch, a blocking device or special handle must be used to

ensure c1at the switch is operated only to the desired position. Reference: APM Rule 309.f

Front 41

Per EN-1, if there is an oil spill who must be notified, and when?

Back 41

Supervisors must contact the on-duty TOBU Environmental Specialist for ALL spilis/

releases within one hour of the supervisor's knowledge of the event.

Reference: EN-1

Front 42

Under what conditions should a portable gantry be avaiiabie for use?

Back 42

Rescue apparatus shall be readily accessible when entering all underground structures

with a depth greater than 4 feet. Reference: APM 1024

Front 43

What are the characteristics of a 400-amp RAK switch?

Back 43

The RAK switch is afour-way, three-position switch with operating characteristics similar to the RAC. The difference being that the No. 1 wav is connected solid to the bus. There are, therefore, only three switched positions. The No. 2 position has only two attitudes

(Open-Bus). This switch will normally be applied to a 4 kV system (7.5 kV voltage class switch).

Front 44

What are the characteristics of a 600-amp RAM switch?

Back 44

The RAM switch may be a two-, three-, four-, five- or six-way switch. The RAM switch may be manually operated or spring operated.

Reference: DOM, SW-3 Attachment 1

Front 45

Describe the application of the RAG switch.

Back 45

RAG switches provide an internal grounding attitude on each switchable position. These switches were developed to simplify the grounding procedures utilized when crews work on underground conductors.

Reference: DOM, SW-5 Attachment 2

Front 46

How far should a BURD enclosure's top cap extend above finished grade?

Back 46

2 inches

Front 47

What is the purpose of spiking cable?

Back 47

Cable spiking is required to prove the cable de-energized when no other method of

testing exists at the work location.

Reference: UGGM, 3.5

Front 48

Under what conditions is it permissible for an employee to enter an underground

structure without anyone else in attendance?

Back 48

l. There are no energized cables or equipment in the structure, and;

2. Aprotective device is placed around the opening, and;

3. Forced ventilation is provided.

Reference: APM Rule 302.a

Front 49

What is a USA, and when would it be required? What company provides SCE with USA service?

Back 49

USA= Underground Service Alert. USA information is provided to SCE by DigA!ert.

State of California Government Code 4216 mandates that anyone doing excavation work shall call at least two working days prior to commencement of any excavation. If you are performing this type of work in California or Nevada, pfease call Underground Service Alert at (811) or {800} 227-2600.

Front 50

Describe what PME and PMH are. How are they different?

Back 50

The PMH is a 2- to 4-compartment cabinet 3-pole, 600 A, gang-operated load-break switches.3 single-pole 200 Air load-break fused disconnect switches, direct bus

terminations, or a combination of these devices. The switches and fuses disconnect switches are each.in separate compartments. Underground cable is used to connect the switches and disconnects.

PME switchgear is similar except that it ls completely dead-front construction and utilizes load-break elbows instead of single-pole disconnect switches.

Reference~ DOM, SW-6 1.0

Front 51

Is it possible to determine, from a circuit map, if entry into an underground structure is restricted? What is required to restrict entry into a structure?

Back 51

Yes. Restricting entry into a structure requires

(1) placement of two postings in the affected structure,

(2) notification of the Switching Center, and

(3} revision of the circuit map.

Front 52

Provide two examples of when spiking a cable might be required.

Back 52

Examples when spiking may be required but not limited to the following:

• A dig-in (main line, or tap line)

• Adding components (J-Bar, 600 amp T-Body [hammer]) • Blown component

• Lead Cable System

Front 53

List and describe the steps for grounding, when replacing cable after a dig-in. The damaged cable is between the pothead and the structure.

Back 53

Identify the circuit (using circuit map(s), cable tags, perform amp check, consider cable size, direction of cable, structure numbers).

De-energize, take clearance and eliminate backfeed.

Prove pothead(s) de-energized, and float the potheads and isolate the concentric.

At the other end of the cable, prove the cable de-energized, isolate cable and concentric.

If contact with the damaged cable/conductor is required, expose the area around dig-in location and remotely spike/cut the cable at dig-in location to prove it de- energized. If minimum approach distance cannot be maintained from exposed conductor, use a testing device (for example, approved high voltage tester/indicator, Wemco}, and test the cable de-energized, then use a spiking tool to prove the cable

de-energized.

6. Replace cable

Front 54

What is the function of a ground adapter device (GAD}?

Back 54

Provides a method of grounding a de-energized section of underground cable that is

equipped with separable 600 A components, using live line tools. Reference: UGGM

Front 55

Provide two examples of when conduit brushes or mandrels should be us

Back 55

Rough or rusty interior surfaces, sand, gravel or other foreign material in the conduit, or protruding grout at joints are tvpical unfavorable conditions.

Reference: DUG, IC 200.1

Front 56

When pulling multiple cables, whv should the pulling attachments be kept even?

Back 56

Do not stagger the cable ends or the pressure from the leading cables may cause the nose of the trailing cable to dig in and block the pull.

Front 57

When pulling multiple cables, whv should the pulling attachments be kept even?

Back 57

Do not stagger the cable ends or the pressure from the leading cables may cause the nose of the trailing cable to dig in and block the pull.

Front 58

What actions are taken following a spill of lubricant, during cable pulling evolutions?

Back 58

If cable lubricant is spilled, it should be washed, swept or squeegeed from the floor using wet mops. Outside, spills should be covered with sand, dirt or gravel. For more details, see the individual Material Safety Data Sheet (MSDS).

Reference: DUG, IC 200 2.2.H

Front 59

Describe what is meant by "slack pulling." ls it a preferred method of pulling cable?

Back 59

Slack pulling is where the pull is stopped and started to accumulate slack in the cable. Slack pulling is not recommended, but may be used as a last option.

Reference: DUG, IC 200 2.2.H

Front 60

For what type of street lighting system are constant-current (regulated output (RO)) transformers used?

Back 60

Series streetlight circuits are supplied by constant current or RegulatetlOutput (RO} transformers which deliver a constant current of 6.6 A.

Reference: DDS-5 5.6

Front 61

What is the specified loading range for RO transformers?

Back 61

RO transformers should be loaded to a minimum of 60 percent and a maximum of 100 percent of their nameplate rating.

Front 62

What is the range of wattages in which Mission Bell streetlight luminaires are available?

Back 62

70 - 400 watts.

Front 63

what situation, primarily, is EPR cable used? Why?

Back 63

PILC-substitute cable is a 3/C EPR-insu!ated1 copper cable designed for replacing failed or deteriorating 3/C PlLC (lead) cable in existing ducts. To minimize cable diameter, tape shields and solid copper ground conductors are used instead of the concentric neutrals common to other polymer {for example, CLP) cable designs.

Reference: DUG, IC 125.1

Front 64

is it permissible to construct a three-phase bank with three single-phase, fused, BURD transformers? Why or why not?

Back 64

Fused BURDs may be used in banks. However, do not use fused BURD transformers in closed delta banks.

Reference: DUG, PD 217 Note 2

Front 65

How often should gas and oxygen monitors be tested for calibration/certification? How are the calibration records handled?

Back 65

Monthly.

The calibration records for the monitor are included in the Foreman's Inspection Report. Reference: DOM, TE-6 and TE-13

Front 66

May PMHs or PM Es be used to de-energize capacitor banks? Explain.

Back 66

No. PMH and PME switches cannot be used for capacitor switching. A sign reading "Capacitor Bank No. Source-Open Capacitor Bank Switch Before Opening This Switch" shall be placed on the compartment door of ali PMH/PME switches used to feed capacitor banks.

Reference: DOM, SW-6 2.1

Front 67

What is the purpose of a ioad-break fuse cabinet {LBFC)? What type of fuses do they use?

Back 67

This fuse cabinet provides a method for fusing 6.9 kV or 9.4 kV residential radials with parallei current-iimiting fuses.

Front 68

After replacing the fuses inside a LBFC, what is the sequence for energizing the cabinet?

Back 68

After fuse replacement, the fuse cabinet shall be energized with the line side load-break

elbow first. Then the load side load-break elbow will be used to pick-up the load. Reference: DOM, PD-4 4.1.H

Front 69

The 4 kV o'd fuse cutouts have become obsolete in SCE circuits. Provide an example of when they should be replaced, and what types of fusing they should be replaced with.

Back 69

The obsolete oil fuse cutout should be replaced whenever an opportunity exists to do so. For example, during major construction work or during any planned power outages.

Oil-fuse cutouts may be replaced with MVS switches, MCAN fuses, or MCLF fuses. Reference: DOM, PD-5 1.0

Front 70

How tight should the basic insulating plug (BlP) be installed on a 600 A component?

Back 70

Use a torque wrench to apply 50 - 60 ft-lb of torque when tightening.

Reference: DUG, JJ 660 3.1

Front 71

How is a 600 A basic elbow connected to another 600 A basic elbow? How is a 600 A basic elbow connected to 200 A elbow?

Back 71

Connector plugs are used to connect 600 A components.

Reducing tap plugs are used to connect 600 A components with 200 A components. Reference: DUG, Figure JJ 660-1

Front 72

How is a 600 A basic elbow connected to another 600 A basic elbow? How is a 600 A basic elbow connected to 200 A elbow?

Back 72

Connector plugs are used to connect 600 A components.

Reducing tap plugs are used to connect 600 A components with 200 A components. Reference: DUG, Figure JJ 660-1

Front 73

When making up secondary Utilco connections, is there a torque specification for the setscrews? If so, what is it?

Back 73

Yes, a minimum of 25 ft-!b.

Front 74

What cable sizes are Utilco connectors featuring two setscrews designed to fit? How many ways are these connectois available?

Back 74

4/0 - 700 kcmil.

Available in 4-way and 6-way types.

Front 75

How many sizes are available of heat shrink sleeves for splicing CLP secondary cables?

For what range of cable sizes is each shrink designed?

Back 75

Two different sizes: 6-inch long type is used for #2 - 350 kcmi! cables; the 9-inch long

type is used for 350 - 750 kcrnif cables.

Front 76

What is the purpose of the Raychem wraparound sleeve repair/sealing kit? How are they applied?

Back 76

The?e kits are used for repairing cracks and splits in secondary cable, including direct buried, and in sealing secoRdary connectors in wet or congested structures. These "wraparound" sleeves may be installed without cutting the cable or disturbing the connector. The silicone gel seals on contact.

Front 77

lf splicing CLP is required, what is the preferred method? What is the alternative method, and when would it be used?

Back 77

Whenever possible, use pre-molded rubber splices in lieu of hand taping. Use taped splicing only if pre-molded components are not available.

Front 78

What color is the bushing that is installed - on J-bars and equipment-for landing 12 kV load-break elbows?

Back 78

Solid red. However, some older versions of this bushing insert may have a red, yeiiow, or gray color-band on the bushing insert surface that mates to the load break elbow. While same older units may not even have color-bands. Be sure to use the correct voltage load break bushing insert.

Front 79

When are ELR and RLR elbows used?

Back 79

ible. Repair (ELR) and Replacement (RLR) elbows shall only be used if standard elbows cannot be used. The ELR and RLR'elbows are not to be used for general elbow

replacement.

The ELR elbow provides an additional elbow iength of approximately 3 inches, and the RLR elbow provides an additional elbow length of approximately 10 inches. ELR and RLR elbows may be used as follows:

• ELR Elbows: Use for replacing damaged or blown standard load-break elbows.

• Replacement (RLR) Elbows: Use when a longer length elbow is required, such as when live-front equipment is replaced with dead-front equipment (for example, PME switches or minipad transformers).

Front 80

What color is the bushing that is installed - on J-bars and equipment - for landing 16 kV load-break elbows?

Back 80

latest version of the 25 kV Class bushing inserts are supplied in a solid blue color. Older versions of this bushing insert may have a red, yellow, or gray color-band on the bushing insert surface that mates to the load break elbow. Some older units may not have color-bands. Be sure to use the correct voltage load break bushing insert.

Front 81

Why must pad-mounted transformer casings be sealed to the pad-mount they rest upon?

Back 81

The gaps between concrete pads and pad-mounted equipment shali be sealed to prevent a wire from entering from the outside into the compartment with exposed live parts.

This will also prevent tampering, reduce moisture entry and deter rodents and vermin

from nesting inside the equipment after the equipment is closed and locked. Reference: DUG, TX 160 2.0

Front 82

What is the definition of a "confined space?"

Back 82

space that has all of the following:

l. ls large enough that an emplovee can bodily enter; and, 2. Has limited openings for entry or exit; and,

3. Is not designed for continuous employee occupancy.