Nevada C-7 Elevation & Conveyance Contractor
1. What does the Nevada C-7 contractor license specifically authorize a
contractor to perform?
ANSWER : The Nevada C-7 license authorizes a contractor to install,
construct, alter, repair, and maintain elevators, escalators, moving walks,
dumbwaiters, material lifts, platform lifts, stairway chairlifts, and other
conveyance systems. It also covers the associated structural and mechanical
components required for these systems to operate safely and in compliance
with applicable codes.
2. Which primary code governs elevator installation and inspection in
Nevada?
ANSWER : Nevada primarily adopts the ASME A17.1/CSA B44 Safety Code
for Elevators and Escalators. This code is published by the American Society
of Mechanical Engineers (ASME) and is the nationally recognized standard
for the design, construction, installation, operation, inspection, testing,
maintenance, alteration, and repair of elevators and escalators.
3. What Nevada state agency is responsible for elevator safety oversight
and licensing of conveyance contractors?
ANSWER : The Nevada Office of the Labor Commissioner, through its
Mechanical Compliance Unit, oversees elevator safety and conveyance
contractor licensing. This office enforces Nevada Revised Statutes (NRS)
Chapter 455 and Nevada Administrative Code (NAC) Chapter 455 related to
elevators and conveyances.
Page
, Nevada C-7 Elevation & Conveyance Contractor
4. What is the purpose of a Certificate of Operation for an elevator in
Nevada?
ANSWER : A Certificate of Operation is the official document issued by the
Nevada Labor Commissioner confirming that an elevator has passed
inspection and is authorized for public use. Without a valid Certificate of
Operation, operating an elevator is illegal. The certificate must be kept on
display in or near the elevator at all times.
5. How often must a standard passenger elevator in Nevada be
inspected?
ANSWER : Standard passenger elevators in Nevada must undergo a periodic
inspection at least once every twelve months. Annual inspections are
required to maintain a valid Certificate of Operation. If an elevator fails
inspection, it must be taken out of service until all deficiencies are corrected
and a re-inspection is passed.
6. What is the minimum traction required for a conventional elevator
hoisting machine?
ANSWER : According to ASME A17.1, the traction between the hoist ropes
and the sheave must be sufficient to stop the elevator car from the contract
speed with the car loaded at 125% of its rated load. The traction ratio must
satisfy the formula T1/T2 = e^(f*theta), where f is the coefficient of friction
and theta is the arc of contact.
7. Define 'counterweight' as used in traction elevator systems.
ANSWER : A counterweight is a weight assembly used in traction elevators
to offset the weight of the car and a portion of the rated load, thereby
reducing the energy needed to move the car. The counterweight typically
equals the weight of the empty car plus approximately 40 to 50 percent of
the elevator's rated load capacity, which balances the system at mid-load for
maximum efficiency.
8. What is a hydraulic elevator and how does it operate?
Page
, Nevada C-7 Elevation & Conveyance Contractor
ANSWER : A hydraulic elevator uses fluid pressure to raise and lower the
car. An electric pump forces hydraulic fluid from a reservoir into a cylinder,
which extends a piston or jack assembly to raise the car. To lower the car, a
valve releases the fluid back to the reservoir under controlled conditions
using gravity. Hydraulic elevators are commonly used in low-rise buildings
of up to six floors.
9. What is the function of a governor in a traction elevator?
ANSWER : A governor is a safety device that monitors the speed of the
elevator car. If the car descends or ascends at a speed exceeding the
governor's trip speed setting, the governor activates and trips the safety
device on the car. The governor rope then engages the safeties, which clamp
the guide rails and bring the car to a controlled stop, preventing a free-fall or
runaway condition.
10. What is an elevator pit and what are the minimum depth
requirements under ASME A17.1?
ANSWER : An elevator pit is the space below the lowest landing served by
the elevator, extending from the floor of the hoistway to the lowest landing
floor sill. ASME A17.1 requires the pit to have sufficient depth to provide
adequate clearance for the car buffer, pit ladder, stop switch, lighting, and
required working space. The minimum pit depth varies by elevator type and
speed, but typically ranges from 3 feet 6 inches to 6 feet or more for higher-
speed elevators.
11. What is an overhead clearance requirement in an elevator
hoistway?
ANSWER : Overhead clearance is the vertical distance from the top of the
elevator car to the underside of the overhead structure when the car is at
the highest landing. ASME A17.1 requires sufficient overhead clearance to
allow maintenance personnel to safely ride on top of the car and to allow the
car to travel beyond the top landing without crushing anyone on the car top.
Typical minimum clearances are at least 6 to 7 feet or more depending on
car speed.
Page
, Nevada C-7 Elevation & Conveyance Contractor
12. What is the purpose of car buffers in an elevator system?
ANSWER : Car buffers are devices installed in the pit below the elevator car
to absorb the kinetic energy of the car in the event the car descends below
the lowest landing. They reduce the impact forces during an emergency
descent. ASME A17.1 recognizes two types: spring buffers, suitable for
lower-speed elevators, and oil buffers, required for higher-speed elevators
above 200 feet per minute.
13. What is a safety device on an elevator car and how does it function?
ANSWER : A safety device (often called a car safety or safeties) is a
mechanical braking device mounted on the car frame that grips the guide
rails to stop the car in the event of rope breakage, governor overspeed trip,
or slack rope condition. The safeties are engaged by the governor rope and
bring the car to a controlled stop by friction. They are classified as
instantaneous or oil buffer (flexible clamp) type based on car speed.
14. What is the rated load of an elevator and how is it determined?
ANSWER : The rated load is the maximum load for which the elevator is
designed and built to safely carry. It is determined during design by
calculating the intended occupancy or use, and it is expressed in pounds or
kilograms. The rated load must be posted in the elevator car and all
components, including ropes, motors, brakes, and buffers, must be designed
to handle 125% of the rated load under test conditions.
15. What is the function of a hoistway door interlock on an elevator?
ANSWER : A hoistway door interlock is a safety device that prevents the
elevator from moving unless all hoistway doors are fully closed and locked.
The interlock also prevents the hoistway doors from being opened from the
landing side unless the elevator car is within the landing zone. This prevents
passengers from falling into an empty hoistway and prevents the car from
moving with doors open.
16. Describe the purpose and function of a car gate or car door on an
elevator.
Page
1. What does the Nevada C-7 contractor license specifically authorize a
contractor to perform?
ANSWER : The Nevada C-7 license authorizes a contractor to install,
construct, alter, repair, and maintain elevators, escalators, moving walks,
dumbwaiters, material lifts, platform lifts, stairway chairlifts, and other
conveyance systems. It also covers the associated structural and mechanical
components required for these systems to operate safely and in compliance
with applicable codes.
2. Which primary code governs elevator installation and inspection in
Nevada?
ANSWER : Nevada primarily adopts the ASME A17.1/CSA B44 Safety Code
for Elevators and Escalators. This code is published by the American Society
of Mechanical Engineers (ASME) and is the nationally recognized standard
for the design, construction, installation, operation, inspection, testing,
maintenance, alteration, and repair of elevators and escalators.
3. What Nevada state agency is responsible for elevator safety oversight
and licensing of conveyance contractors?
ANSWER : The Nevada Office of the Labor Commissioner, through its
Mechanical Compliance Unit, oversees elevator safety and conveyance
contractor licensing. This office enforces Nevada Revised Statutes (NRS)
Chapter 455 and Nevada Administrative Code (NAC) Chapter 455 related to
elevators and conveyances.
Page
, Nevada C-7 Elevation & Conveyance Contractor
4. What is the purpose of a Certificate of Operation for an elevator in
Nevada?
ANSWER : A Certificate of Operation is the official document issued by the
Nevada Labor Commissioner confirming that an elevator has passed
inspection and is authorized for public use. Without a valid Certificate of
Operation, operating an elevator is illegal. The certificate must be kept on
display in or near the elevator at all times.
5. How often must a standard passenger elevator in Nevada be
inspected?
ANSWER : Standard passenger elevators in Nevada must undergo a periodic
inspection at least once every twelve months. Annual inspections are
required to maintain a valid Certificate of Operation. If an elevator fails
inspection, it must be taken out of service until all deficiencies are corrected
and a re-inspection is passed.
6. What is the minimum traction required for a conventional elevator
hoisting machine?
ANSWER : According to ASME A17.1, the traction between the hoist ropes
and the sheave must be sufficient to stop the elevator car from the contract
speed with the car loaded at 125% of its rated load. The traction ratio must
satisfy the formula T1/T2 = e^(f*theta), where f is the coefficient of friction
and theta is the arc of contact.
7. Define 'counterweight' as used in traction elevator systems.
ANSWER : A counterweight is a weight assembly used in traction elevators
to offset the weight of the car and a portion of the rated load, thereby
reducing the energy needed to move the car. The counterweight typically
equals the weight of the empty car plus approximately 40 to 50 percent of
the elevator's rated load capacity, which balances the system at mid-load for
maximum efficiency.
8. What is a hydraulic elevator and how does it operate?
Page
, Nevada C-7 Elevation & Conveyance Contractor
ANSWER : A hydraulic elevator uses fluid pressure to raise and lower the
car. An electric pump forces hydraulic fluid from a reservoir into a cylinder,
which extends a piston or jack assembly to raise the car. To lower the car, a
valve releases the fluid back to the reservoir under controlled conditions
using gravity. Hydraulic elevators are commonly used in low-rise buildings
of up to six floors.
9. What is the function of a governor in a traction elevator?
ANSWER : A governor is a safety device that monitors the speed of the
elevator car. If the car descends or ascends at a speed exceeding the
governor's trip speed setting, the governor activates and trips the safety
device on the car. The governor rope then engages the safeties, which clamp
the guide rails and bring the car to a controlled stop, preventing a free-fall or
runaway condition.
10. What is an elevator pit and what are the minimum depth
requirements under ASME A17.1?
ANSWER : An elevator pit is the space below the lowest landing served by
the elevator, extending from the floor of the hoistway to the lowest landing
floor sill. ASME A17.1 requires the pit to have sufficient depth to provide
adequate clearance for the car buffer, pit ladder, stop switch, lighting, and
required working space. The minimum pit depth varies by elevator type and
speed, but typically ranges from 3 feet 6 inches to 6 feet or more for higher-
speed elevators.
11. What is an overhead clearance requirement in an elevator
hoistway?
ANSWER : Overhead clearance is the vertical distance from the top of the
elevator car to the underside of the overhead structure when the car is at
the highest landing. ASME A17.1 requires sufficient overhead clearance to
allow maintenance personnel to safely ride on top of the car and to allow the
car to travel beyond the top landing without crushing anyone on the car top.
Typical minimum clearances are at least 6 to 7 feet or more depending on
car speed.
Page
, Nevada C-7 Elevation & Conveyance Contractor
12. What is the purpose of car buffers in an elevator system?
ANSWER : Car buffers are devices installed in the pit below the elevator car
to absorb the kinetic energy of the car in the event the car descends below
the lowest landing. They reduce the impact forces during an emergency
descent. ASME A17.1 recognizes two types: spring buffers, suitable for
lower-speed elevators, and oil buffers, required for higher-speed elevators
above 200 feet per minute.
13. What is a safety device on an elevator car and how does it function?
ANSWER : A safety device (often called a car safety or safeties) is a
mechanical braking device mounted on the car frame that grips the guide
rails to stop the car in the event of rope breakage, governor overspeed trip,
or slack rope condition. The safeties are engaged by the governor rope and
bring the car to a controlled stop by friction. They are classified as
instantaneous or oil buffer (flexible clamp) type based on car speed.
14. What is the rated load of an elevator and how is it determined?
ANSWER : The rated load is the maximum load for which the elevator is
designed and built to safely carry. It is determined during design by
calculating the intended occupancy or use, and it is expressed in pounds or
kilograms. The rated load must be posted in the elevator car and all
components, including ropes, motors, brakes, and buffers, must be designed
to handle 125% of the rated load under test conditions.
15. What is the function of a hoistway door interlock on an elevator?
ANSWER : A hoistway door interlock is a safety device that prevents the
elevator from moving unless all hoistway doors are fully closed and locked.
The interlock also prevents the hoistway doors from being opened from the
landing side unless the elevator car is within the landing zone. This prevents
passengers from falling into an empty hoistway and prevents the car from
moving with doors open.
16. Describe the purpose and function of a car gate or car door on an
elevator.
Page
