Electrical Level 2 Module 10

In residential applications, the available fault current is seldom higher then

10,000 amps

What is normally the highest short circuit current in residential applications?

10,000A

Every circuit breaker must have its interrupting rating shown on the circuit breaker, unless it is rated for

5,000A

What is the highest voltage rating for circuit breakers used on DC systems that UL recognizes?

600V

Which of the following best describes a dual element fuse?

A fuse having an overcurrent limit and a time delay before activation

Each group of circuit breakers are classified by the largest

Ampere rating

What color is printed on the labels of standard interrupting capacity circuit breakers?

Black

The organizations that test and list circuit breakers are

CSA and UL

Which of the following is defined by UL as a device that trips when a fault current to ground is 6mA or more?

Class A

At current below threshold of about 1000 A, the current limiting circuit breaker performs in a manner similar to

Conventional thermomagnetic circuit breakers

The name given to the time-current relationship among a number of overcurrent devices connected in series, such as fuses in a main feeder, subfeeder, and branch circuits.

Coordination

NEC section 240

Covers overcurrent protection

Circuit breakers are classified according to the given

Current range

This type of circuit breaker has an interrupting rating of 65,000 A symmetrical at 240 VAC

FH-type circuit breaker

What are the two types of GFCI receptacles?

Feed-through and Non feed-through

Which of the following best describes where the NEC allows the use of Edison base fuses?

For replacements in existing installations

These are types of automatic overload devices that are normally used in electrical circuits to prevent fires and the destruction of the circuit in its associated equipment.

Fuses and circuit breakers

When a common molded case circuit breaker trips, in what position will the operating handle be?

Halfway between the On and Off postion

Where is the ampere rating normally marked on circuit breakers?

On the handle

Where is the amp rating of a circuit breaker located?

On the handle of the device

These type of drawings do not have to be detailed

Single Line Schematic drawings

______________ have a very high speed of response to overcurrents.

Single element fuses

Which of the following is the most important consideration when working with overcurrent protection devices?

The correct interrupting capacity

On renewable cartridge fuses, which part of the fuse is normally renewed?

The link

What must be used in conjunction with Type S plug fuses when they are installed in a fuse holder?

Type S adapter

Cartridges fuses used for branch circuit protection must be marked with the

ampere rating, voltage rating and the Interrupting rating.

The interrupting rating of a circuit breaker is as important in application as the voltage and current ratings and should be considered

each time a Breaker is applied