IDA-201 Unit 19 Flashcard 1

Front

What does N.O. stand for in electrical terms?

Back

N.O. stands for Normally Open, which refers to a contact that is open when not energized.

Front

What is the primary function of contactors in electrical systems?

Back

Contactors are designed to control loads that draw more than 20 A of current.

Front

What can happen if contactor contacts are badly pitted?

Back

Badly pitted contactor contacts can cause the motor to burn out.

Front

What is the most common material used on the surface of electrical contacts?

Back

The most common material used on the surface of contacts is silver.

Front

What is the role of a fuse or circuit breaker in an electrical circuit?

Back

A fuse or circuit breaker protects individual components, not the entire circuit.

Front

What does it mean if a contact is described as 'normally closed'?

Back

A normally closed contact is one that is closed (conducting) when not energized.

Front

What is the difference between a fuse and a circuit breaker?

Back

A fuse is a one-time use device that melts to break the circuit, while a circuit breaker can be reset after tripping.

Front

Why is silver commonly used in electrical contacts?

Back

Silver is used in electrical contacts due to its excellent conductivity and resistance to corrosion.

Front

What is the significance of contactor ratings?

Back

Contactor ratings indicate the maximum load they can safely control without damage.

Front

How does a contactor operate?

Back

A contactor operates by using an electromagnet to open or close contacts in response to an electrical signal.