A customer fed by a secondary underground cable complains about erratic power. Voltage reading at the customers may show normal voltage. What else should be checked? - ️️A break in the insulation is often a high resistance fault, water gets in and turns into a high resistance fault
Distributio...
Lineman 74 Unlocking Potential Exam
Questions
A customer fed by a secondary underground cable complains about erratic power. Voltage reading at
the customers may show normal voltage. What else should be checked? - ✔ ✔ A break in the
insulation is often a high resistance fault, water gets in and turns into a high resistance fault
Distribution feeders tend to have a combination of resistive load and inductive load creating a lagging
power factor what equipment is installed to counter a lagging power factor - ✔ ✔ capacitors
How are the voltage and current of an incoming high voltage transmission line measured - ✔ ✔ The
voltage is measured from voltage transformers and the current is measured from circuit transformers
How can a boom tip winch break the boom of a digger derrick - ✔ ✔ The winch is stronger than the
boom and can hold more weight
How can broken strands cause problems when using an old conductor to pull in a new conductor - ✔
✔ Strand will break and unravel and then fall onto stuff under it
How can opening a ground connection in a substation be a hazard - ✔ ✔ Opening a ground can
interrupt current and create a high spark in voltage
How do we reduce rotation gear failure - ✔ ✔ Keep it below a 5 degrees slope, Don't pull a load
how does working on a 5 degree slope affect an aerial device - ✔ ✔ Gear failure, rolling hazard
How is corona loss minimized on a transmission line - ✔ ✔ Increase space between conductors and
smooth rough edges
how much current would a 240v heater with 20ohms of resistance draw - ✔ ✔ 12 watts
In relation to peak value of AC power, What value do an ordinary ammeter and voltmeter measure - ✔
✔ The effective value
Lifting with a digger derrick winch- when lifting materials and equipment and the weight is known the
lifting chart is to be used to prevent damage to the boom. What if we don't know the weight of the
materials? - ✔ ✔ Make all lifts by booming up first
Name 2 factors that influence the specification for the size of the conductor needed - ✔ ✔
Conductor must be large enough to keep voltage drop to an acceptable limit
Conductor must be large enough to limit line loss
, Name 3 methods used to extinguish arc in various switch gear - ✔ ✔ Oil, SF 6 gas and vacuum
Name 3 ways an operator can reduce the risk involved with operating, material handling and aerial
devices - ✔ ✔ No side loading, check capacity chart, maintain maximum approach distance
Name one advantage of using a preformed tie over a hand formed tie when trying a conductor on the
top of top tie insulator - ✔ ✔ It will be easier and more efficient than a hand form that is less
dependent on linemen making perfect ties
Name six segments that make up a distribution system - ✔ ✔ Sub transmission circuits, distribution
stations, primary feeder, distribution transformer, secondary systems, customer connections
Name the two forms of induction that make up electromagnetism - ✔ ✔ Electric field induction and
magnetic field induction
Name three elements that have the most direct influence on safe work - ✔ ✔ Lock out tag out,
Employee training, rules and regulations
Name two advantages for converting Delta to WYE circuit - ✔ ✔ Safer and more economical
Name two ways to positively identify a neutral wire - ✔ ✔ Ground wire attaches to the neutral wire.
Check position on pole for ground
There are 2 fundamental ways a person can be protected working around a vehicle when a boom makes
contact with an energized conductor. What are they? - ✔ ✔ Keeping a safe distance away from the
truck and grounding the truck
True/False Anytime a person is in a parallel with any load in a circuit, that person is exposed to some
voltage and some current regardless of the amount of resistance being offered to the circuit - ✔ ✔
True
True/False side loading a boom of an aerial unit while using material handler is hazardous, the operator
shall make vertical lifts only - ✔ ✔ True
True/False the strength of polymeric suspension insulator is in the core - ✔ ✔ True
True/False when a conductor is sagged too tight, the conductor can be subject to too much tension - ✔
✔ True
What act is required to generate power in almost all commercial generators - ✔ ✔ Electricity
involves the movement of wire coils in a magnetic field
What advantages are there for three phase versus a single phase circuit - ✔ ✔ Large generators and
large motors are more efficient and considerably smaller as three phase units compared to singe.
Magnetic field automatically rotates
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