Deck 9: Hazardous Location Wiring

Question 1

Describe type n equipment, and list its three subcategories.

Answer 1

Equipment that is provided with type n protection is permitted to be installed in Zone 2 locations.This type of equipment is designed in a manner such that it is not capable of igniting a surrounding hazardous vapor.Furthermore, type n equipment is broken down into three subcategories -nA, nC, and nR.The subcategories represent different design characteristics of the equipment or enclosures.

Question 2

An example of an enclosure marking may be Zone 1, AEx, d, IIA, T4, Gb.What is the meaning of 'Gb,?

Answer 2

'G' stands for gas, and 'b' indicates a high level of protection.

Question 3

What are the steps in wiring a hazardous location?

Answer 3

The first step for wiring in a hazardous location is to determine the type of material that makes the area hazardous.Next, determine whether the type of facility is considered to be a special occupancy, which is described in one of the articles of the Code.

Question 4

Type ____________________ is intrinsically safe equipment intended for use in Zone 0.

Question 5

Class I locations are characterized by flammable flyings and fibers.

Question 6

Class ____________________ is characterized by flammable dust.

Question 7

Equipment type ____________________ is purged and pressurized.

Question 8

Describe Type d equipment.

Question 9

As a result of major changes to the 2011 Code, equipment marking designations for protection may be a prefix or suffix letter to indicate D for dust, G for gas, and M for mining.

Question 10

Flameproof protection is identified by the letter ____________________.

Question 11

A Division 1 area is one in which, under normal operating conditions, a hazardous material is present in dangerous quantities only because of accidental spills or other unusual circumstances.

Question 12

Extra care must be taken to make sure the grounding path in a hazardous location is of ____________________ impedance.

Question 13

Class I is separated into which three zones?

Question 14

One of the major changes to the 2011 Code is that a new definition was added for ____________________ dust.

Question 15

The division line between hazardous and non-hazardous may be a physical barrier, or it may simply be a distance limit.

Question 16

Type ___________________ equipment is known as increased safety equipment.

Question 17

What is the meaning of 'Zone2/1'?

Question 18

What happens to ignition gases during an internal explosion?

Question 19

A Division ___________________ area is one in which the hazardous material is likely to be present.

Question 20

An area is considered hazardous because of the highly flammable nature of a vapor, gas, dust, or solid material that may be easily ignited to cause fire or an explosion.