NJATC Apprentice Lineman Outside 2nd Year Level IV Exam Review

Flashcards covering key concepts and exam questions from the NJATC Apprentice Lineman Outside 2nd Year, Level IV test material.

What are the lines or waves of magnetic force produced by an inductor called?

Lines of flux

What term describes the ability of a moving or changing magnetic field to induce a voltage into a conductor?

Inductance

What happens to the voltage drop if the current to the load is increased?

It will increase.

What is the voltage drop per $1,000\text{ feet}$ of $1/0$ copper wire (resistance = $0.122\text{ ohms per }1,000\text{ feet}$) when $40\text{ amperes}$ of current are flowing through the wire?

$$4.88\,V$$

In the equation $E_{VD} = \frac{K \times I \times L}{A}$, what does the variable $K$ represent?

Resistivity constant of material

Which number on a residential meter's faceplate refers to watt-hours per turn of the disc?

$$K_h$$

What causes the metal disc in electromechanical meters to turn due to induction from the potential coil?

Eddy currents

Power factor is the ratio between which two peak values?

kW peak and kVA peak

What is the overall demand a customer puts on a system over a given period known as?

Maximum demand

Power factor is a ratio of peak ____ to peak ____.

kW to kVA

What two main types of faults, other than lightning surges, cause circuit breakers to operate on transmission systems?

Ground and phase

Which low voltage switches are responsible for circuit breaker activation?

Relays

How many types of faults, or combinations of faults, can show up and be measured at a terminal where relays detect them?

$$5$$

What does the acronym BIL stand for in relation to insulator flashover voltage?

Basic impulse level

If so equipped and properly interrogated, SCADA systems and OCR controls can give what information about a fault from the breaker?

The mileage

How are many FCIs built to prevent tripping due to back-feed currents?

With a high degree of immunity

With directional FCIs on overhead lines, where will the fault be located?

Between the last green indicator and first red indicator, unless the FCI is set on an unfused lateral tap

To prevent false readings, many FCIs have a high degree of what to back-feed currents?

Immunity

What is one method used to ground a transmission steel tower?

Counterpoise

When backfilling an excavation, what compaction to relative density is required for granular soil?

$$70\%$$

When a helicopter is building a tower in sections, what are placed on the tower?

Temporary brackets

Before another section of a steel tower is placed, what minimum percentage of the bolts must be in place and tightened on the previous section?

At least $50\%$

Besides socket wrenches, what other tools are normally used on steel tower construction?

Spud wrenches

What do manufacturers use to protect steel after a tower has been cut and drilled?

Dip galvanizing

When joining copper and aluminum conductors, what rule must always be followed?

Always put aluminum on the top

When checking conductor sag on an existing line, what is the best method to use?

Return wave method

What can a phasing tester be used as?

A potential, insulator, or Hipot tester

What should be prepared in case of a worker's faulty memory, ensuring the tester is removed from the line and not left hanging?

Phasing diagram

When testing corresponding energized lines, what reading should the tester indicate?

$$0$$

What must be done to voltage regulators prior to closing in disconnects that will tie in two circuits?

Set on neutral position and locked out

What percentage of their nameplate rating capacity are transformers designed to hold for a short period?

$$125\%$$

How does overload capacity benefit a customer?

By sparing them from paying for the equipment they do not need

Overload capacity is a feature that allows power companies to offset what to some extent?

Cost and labor

Every piece of equipment has what type of built-in capacity that far exceeds its kilovolt-ampere rating?

Short-term

What action will reverse the rotation of a 3-phase motor?

Interchanging any two leads

What phase designations and markers are used by utilities?

ABC, XYZ, 123

When should phase rotation be known?

When a service is taken down to repair or replace a 3-phase bank

How do you verify that a rotation meter is working correctly?

Swap two leads and verify the meter is turning the other direction

Through what mechanism can back-feed occur?

Load-supplied power

If a meter has been pulled due to nonpayment, what should be done prior to setting a new meter?

Perform a proper voltage check.

If a main line neutral must be cut, what safety precaution must be taken?

A jumper must be in place before cutting the neutral.

What equipment will take longer to reset in cold weather or if not properly maintained?

Sectionalizers

What should be removed when working on a downed line fed from a single-phase OCR?

Primary leads

Why should Qualified Electrical Workers never assume the operating handle of an OCR is correct?

The operating handle is a mechanical device, which may be defective.

What capacitor-discharge device operates by building up a capacitor charge and discharging it through the cable?

Thumper

What are the two most popular types of primary fault locators?

Thumpers and radar

A thumper operates by building up what type of charge?

Capacitor charge

Once the sectionalizing device has de-energized the fault line, what is the next step?

Conducting a drive-through patrol

Since thumpers are capacitor-discharge devices, what two safety protocols are extremely important when using this device?

Grounding and barricading

What type of circuit is created when one or more conductors have separated and are usually laying on the ground?

Open circuit