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LADWP Electric Station Operator
Certification Exam 2026/2027 |
Comprehensive Exam Review | Practice
Questions, Answer Rationales &
Electrical Station Operations Prep
Please list the 6 major categories of discussion for any tailboard.
a. Methods of emergency notification
b. What is our job plan?
c. What is energized? What is not? What are the clearance points?
d. What are the hazards associated with the job?
e. What are the assignments, groups or individuals?
Special precautions, special equipment, PPE?
g. Does everyone understand/ask questions?
What are the major categories of a Substation Maintenance switching tailboard?
a. Methods of emergency notifications
b. What is our switching assignment?
c. How will we accomplish the switching?
d. Have I verified equipment to be operational?
e. What are the hazards involved/ PPE required?
f. What are my clearance points?
g. Are grounds installed? If so, where?
,….,,,./.,./.,./../../../…./././././.,.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,.,.,.
What are the basic safe work practices observed in a 230KV or 500KV receiving station?
Check in to station upon arrival, close and lock gate after entering. Maintain MAD for personnel
and equipment as well as safe working clearances at all times 500KV- PTG 11'11"PTP
19'9"230KV- PTG 5'8"PTP 9'2"115KV- PTG 3'4" PTP 4'7" 69KV- PTG 2'11" PTP 3'9" PWalk
down yard and visually inspect for damaged equipment or missing/broken grounds.tailboard with
other crews in working in the same area. Maintain speed limits and follow roadways.
What insulating mediums are used in EHV breakers?
SF6 gas, ultra-dry high pressure air, polymer, ceramics, air, epoxy, silicone
What does a WIKA gauge measure?
WIKA is a brand. Usually, it is measuring gas pressure.
What is the minimum % of gas density that SRP allows in an EHV breaker?
98% on all new breakers,98% on Palo Verde Breakers, 97% on all other voltage class breakers
including older 500KV breakers.
Is SF6 gas harmful and or a hazardous material?
Yes, it displaces oxygen and can create a toxic substance when used to suppress an electric arc. It
is invisible, odorless, and tasteless.
Explain the difference between a live tank and a dead tank breaker.
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A live Tank breaker has external energized tanks that are isolated from ground. These tanks
contain the interrupting contacts, which are above ground potential.
A dead tank breaker has their interrupting contacts enclosed in tanks that are at ground potential.
What type of EHV breaker has a free standing C.T.?
A live tank breaker.
Preventative breaker maintenance consists of what?
Tailboard and be working under a grounded clearance. Power factor test, ductor/micro-ohm test
(the resistance of closed contacts, timing test ( opening and closing) , checking moisture, purity
and density of SF6 gas (and content of SO2 if any), pressure switch settings, service the
compressors (oil change and belt checks, pump times), check heaters, mechanism travel
measurements, alarm checks ( low gas and low gas lock outs, motor trouble/fail) , and an
inspection of the overall condition of the breaker.
Name the different types of operating mechanisms and explain the safety hazards associated with
each.
Air Hazards include: pressurized containment vessel, air leaks are not visible, fittings, hoses,
regulators and air tools need to be rated for the pressure to be applied, beware of moving parts,
drain air pressure before performing maintenance.
Hydraulic hazards: pressurized containment vessel, containment vessel has a nitrogen pre-charge
pressure even after hydraulic pressure has been drained, hydraulic oil is flammable, beware of
moving parts, drain hydraulic pressure before performing maintenance.
Spring hazards: beware of moving parts, discharge spring pressure before performing
maintenance, spring can be charged in both open and closed breaker positions.
LADWP Electric Station Operator
Certification Exam 2026/2027 |
Comprehensive Exam Review | Practice
Questions, Answer Rationales &
Electrical Station Operations Prep
Please list the 6 major categories of discussion for any tailboard.
a. Methods of emergency notification
b. What is our job plan?
c. What is energized? What is not? What are the clearance points?
d. What are the hazards associated with the job?
e. What are the assignments, groups or individuals?
Special precautions, special equipment, PPE?
g. Does everyone understand/ask questions?
What are the major categories of a Substation Maintenance switching tailboard?
a. Methods of emergency notifications
b. What is our switching assignment?
c. How will we accomplish the switching?
d. Have I verified equipment to be operational?
e. What are the hazards involved/ PPE required?
f. What are my clearance points?
g. Are grounds installed? If so, where?
,….,,,./.,./.,./../../../…./././././.,.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,.,.,.
What are the basic safe work practices observed in a 230KV or 500KV receiving station?
Check in to station upon arrival, close and lock gate after entering. Maintain MAD for personnel
and equipment as well as safe working clearances at all times 500KV- PTG 11'11"PTP
19'9"230KV- PTG 5'8"PTP 9'2"115KV- PTG 3'4" PTP 4'7" 69KV- PTG 2'11" PTP 3'9" PWalk
down yard and visually inspect for damaged equipment or missing/broken grounds.tailboard with
other crews in working in the same area. Maintain speed limits and follow roadways.
What insulating mediums are used in EHV breakers?
SF6 gas, ultra-dry high pressure air, polymer, ceramics, air, epoxy, silicone
What does a WIKA gauge measure?
WIKA is a brand. Usually, it is measuring gas pressure.
What is the minimum % of gas density that SRP allows in an EHV breaker?
98% on all new breakers,98% on Palo Verde Breakers, 97% on all other voltage class breakers
including older 500KV breakers.
Is SF6 gas harmful and or a hazardous material?
Yes, it displaces oxygen and can create a toxic substance when used to suppress an electric arc. It
is invisible, odorless, and tasteless.
Explain the difference between a live tank and a dead tank breaker.
, ….,,,./.,./.,./../../../…./././././.,.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,./.,.,.,.
A live Tank breaker has external energized tanks that are isolated from ground. These tanks
contain the interrupting contacts, which are above ground potential.
A dead tank breaker has their interrupting contacts enclosed in tanks that are at ground potential.
What type of EHV breaker has a free standing C.T.?
A live tank breaker.
Preventative breaker maintenance consists of what?
Tailboard and be working under a grounded clearance. Power factor test, ductor/micro-ohm test
(the resistance of closed contacts, timing test ( opening and closing) , checking moisture, purity
and density of SF6 gas (and content of SO2 if any), pressure switch settings, service the
compressors (oil change and belt checks, pump times), check heaters, mechanism travel
measurements, alarm checks ( low gas and low gas lock outs, motor trouble/fail) , and an
inspection of the overall condition of the breaker.
Name the different types of operating mechanisms and explain the safety hazards associated with
each.
Air Hazards include: pressurized containment vessel, air leaks are not visible, fittings, hoses,
regulators and air tools need to be rated for the pressure to be applied, beware of moving parts,
drain air pressure before performing maintenance.
Hydraulic hazards: pressurized containment vessel, containment vessel has a nitrogen pre-charge
pressure even after hydraulic pressure has been drained, hydraulic oil is flammable, beware of
moving parts, drain hydraulic pressure before performing maintenance.
Spring hazards: beware of moving parts, discharge spring pressure before performing
maintenance, spring can be charged in both open and closed breaker positions.
