Step 5 Flashcards
You are in the process of phasing two circuits, what is the first thing that should be checked?
Energized lines and a working phasing set.
The hands of a clock travels from 3:00 to 9:00 the hands has traveled how many degrees?
180 degrees
During a tailboard briefing a “no test”will be ______ prior to rubber gloving above7,500 volts
discussed
What voltage listed below are a delta connection?
120/240 single phase
240 three phase
What is a common neutral? Explain.
Its a Neutral conductor that is shared by primary and secondary
The ideal circumstance for trying circuits together is to have_______ across the disconnects
No voltage
The most important step in cable termination is
the restoration of the insulating system
Service wires must extend at least ___ inches from the weather head.
36
What is the purpose of a switched capacitor bank?and a fixed capacitor
increases power factor and reduces lagging components
switch banks can be taken in and out of service and fixed can not
Which of the following actions will cause a decreases in the amount of voltage drop in a circuit?
Increasing the size of the conductors
A megger is used to measure?
High resistance
What does G.O. 95 stand for?
California state overhead construction rules
The worker is “insulated” by using?
rubber gloves or rubber goods
The worker is “isolated” by using?
bucket truck or isolated platform
The scale on a set of blueprints is 1/8 inch equals 100 feet, how many feet would 3-3/4 inches be on the blueprint.
38=24
3/4=6/8 32=6 42=8
24+6=30
30100=(3,000)
A distribution transformer should be _____ before changing taps.
De-energized
According to OHM’s law, voltage is equal to ___?
current * resistance
I*R
Explain how you check & record rotation an a three phase service?
check with rotation meter and use phase tape to mark the phases or mark them 123
What is known as High,Wild,Stinger, or Power Leg
A leg of 4 wires that has voltage of 208/277
List the 6 Steps or parts of a tailboard
1) Purpose of the job
2) My Job
3) Others Job
4) Foreman’s method
5) Hazards of the job and how to overcome them
6) Location
Can you work bonding on 54.5 KV circuit with rubber gloves____?
No
List 3 conditions that would cause induced voltage on a line
1) Power lines
2) Lightning strikes
3) Wind static
The part of underground cable the equalized stress on the insulation is known as the________.
Semi-Conductor
Explain why is electrical power transmitted at high voltage?
The higher the voltage the lower the line lose
What two types of transformers are used for primary metering?
First- Current Transformer
Second- Power Transformer
you are going to use a mac on a single phase line to cut in a deadend before using the jumper it should be inspected. List 3 items you would check
1) Head is tight
2) Insulation is in good shape no cracks or cuts
3) Mac is big enough to to handle the amp
Your doing a transformer change out from a 25KVA to a 50KVA single phase, what will you do with the secondary leads before removing the old transformer?
Disconnect the secondary leads to eliminate back feed and mark your leads
What is the minimum distance a secondary service must clear a phone cable in the middle of a span in California?
24”
Explain how to test a transformer for polarity
put a jumper h1 and x1 put meter h1 and x4 or furthest to the right and apply 120 to h1 and h2 and if the voltage is higher than applied voltage it is additive and if the voltage is lower than the applied voltage it is subtractive
The primary purpose of the National Electrical Safety Code is________
to provide safety to the public and electrical workers
List the classes of burns
1st degree- redness swollen sunburn
2nd degree- swollen blistered watery
3rd degree- black and white charred
What is the minimum working diastase
above 15KVA
below 15KVA
Above 15 KVA- 2ft 4in
Below 15KVA - 2ft 1in
What does N.E.C.A. stand for
National Electrical Contractors Association
Hot hoist or strap are electrically rated and tested for how many volts?
zero
What is the phase to phase voltage of a 12,460 volt feeder?
12,460
Can we use a 4,160 volt rated transformer on a 7,200 volt line?
yes
Rubber gloves shall be given the ________ at least once a day while in use.
Air and water test
According to OSHA fiberglass rein forced plastic live line tools shall be tested at _______ volts per foot for 5 minutes
100,000
You must wear rubber gloves to repair a open neutral on a 4 wire 12KVA circuit?
Yes
At what voltage must you wear rubber sleeves in California?
7,500
Why should you check voltage across the open leg of a delta bank before making the final connection? What are you looking for?
Check for phasing to make sure they match
What is the function of an automatic re-closure?
A mechanism that can automatically close the breaker after it has been opened due to a fault.
In series street lighting circuit, the total circuit voltage is _____?
The sum of the voltage across them
In a transformer vector, the phases are how many degrees apart?
120 degrees apart
The most dangerous position to make a lift with a mobile crane.
Over the corner
