Chapter 7 Alternating current, Power Distribution, and Voltage Terms

Capacitive Reactance

A capacitor's opposition to the flow of current

Peak voltage

Alternating current reaches a peak at 90 degrees.

Power Factor

How efficiently equipment uses power. Also, ratio between the true power and the apparent power.

Effective voltage

In A-C this is 0.707 times the peak (Maximum) voltage.

Inductance

The fluctuation of the magnetic strengths in an AC circuit, and in conductors cutting through more than one magnetic field, induces a voltage that counteracts the original voltage.

Phase

an AC circuit is the number of currents alternating at different time intervals in the circuit.

3 phase

current with 3 phases

Single phase

current would have only a single current.

Sine wave

is often used a graphical representation of alternating current.

Inductive reactance

is the opposition to the change in flow of alternating current, which produces an out-of-phase condition between voltage and amperage.

Reactance

is the resistance that alternating current encounters when it change flow.

Delta system

is used in structures that require a large supply to motors and other three-phase equipment.

Wye

offers the versatility of using three-phase alternating current and the possibility of supplying many 120-volts for lights, appliances, and other 120-volts for equipment.

Alternator

sends an electric current to the battery to keep the battery charged and also powers the other electronic gadgets on your car when the engine is running

Frequency

the number of complete wavelengths that pass a point in a given time

Impedance

the sum of the resistance and reactance in an AC current