51-60 Definitions

Question 1

AC Overcurrent Relay

Answer 1

Functions when the current in an AC circuit exceeds a given value.

Question 2

AC Circuit Breaker or Contactor

Answer 2

One whose principal function is usually to interrupt, short-circuit or fault currents

Question 3

Exciter of Generator Relay

Answer 3

One which forces the building up of the DC machine field during starting and/or functions when the machine voltage has built up to a given value.

Question 4

High Speed Circuit Breaker

Answer 4

A circuit breaker that starts to reduce the current in the main circuit after the occurrence of DC overvoltage, or an excessive rate of current rise

Question 5

Power Factor Relay

Answer 5

Operates on a given power factor in an AC circuit.

Question 6

Field Application Relay or Device

Answer 6

Used to control automatically the application of AC motor field excitation at some predetermined point in the slip cycle

Question 7

AC Overvoltage Relay

Answer 7

Functions on a given value of AC overvoltage

Question 8

Voltage Balance Relay

Answer 8

Operates on a difference in voltage between two circuits