Special occupancies: Texas Journeyman Electrician Practice Questions

Which NEC article covers swimming pools, spas and hot tubs?

Pools, fountains, spas and hot tubs are in Article 680.

A Class I hazardous location is one where the hazard comes from:

Class I is flammable gases or vapors; Class II is combustible dust; Class III is ignitible fibers and flyings.

A grain elevator with combustible dust in the air is classified as a:

Combustible dust puts a location in Class II.

Which NEC article covers health care facilities?

Health care facilities are in Article 517. 511 is commercial garages, 518 is assembly occupancies and 547 is agricultural buildings.

Legally required emergency systems (such as exit and egress lighting) are covered by:

Emergency systems are Article 700; 701 is legally required standby, 702 is optional standby, 705 is interconnected power sources.

Which NEC article covers marinas, boatyards and docking facilities?

Marinas and docking facilities are in Article 555; 550 is mobile homes and 551 is recreational vehicles and RV parks.

In the hazardous location system, what separates Class I, Division 1 from Class I, Division 2?

Under 500.5(B), Division 1 locations have ignitible concentrations under normal conditions; Division 2 locations have them only through abnormal events such as leaks or ventilation failure.

A textile mill has easily ignitible fibers and flyings in the air. Which hazardous location class applies?

Section 500.5(D) defines Class III locations by ignitible fibers or flyings; Class I is gases and vapors and Class II is combustible dust.

Gasoline and propane vapors belong to which Class I material group?

Section 500.6(A) places gasoline, propane and similar materials in Group D; acetylene is Group A, hydrogen Group B, and Group E is a Class II (metal dust) group.

Grain dust and flour dust belong to which Class II group?

Section 500.6(B) puts grain, flour, starch, wood and plastic dusts in Group G; Group E is metal dust and Group F is carbonaceous dust such as coal.

What does the temperature class (T-code) marked on hazardous location equipment tell you?

Section 500.8(C) requires a temperature class marking that shows the equipment's maximum surface temperature, which must stay below the autoignition temperature of the gas or dust present.

Which protection technique is typical for equipment in a Class II, Division 1 location?

Section 500.7 lists dust-ignitionproof equipment for Class II, Division 1; explosionproof is the Class I, Division 1 technique and nonincendive is a Division 2 technique.

Threaded conduit joints in a Class I, Division 1 location must be made up with at least how many fully engaged threads?

Section 500.8(E)(1) requires NPT-threaded conduit and fittings to be made wrenchtight with at least five full threads fully engaged.

According to the NEC, what is required in each conduit run that leaves a Class I, Division 1 location?

Section 501.15 requires a sealing fitting in each conduit run that leaves a Class I, Division 1 location, so gases and vapors cannot travel through the conduit into the unclassified area.

In Class I, Division 1, how close to an enclosure containing arcing devices must the conduit seal be?

Section 501.15(A)(1) requires seals within 18 in (450 mm) of enclosures that contain arcing or high-temperature devices.