問題一覧
1
Oil buffers are required below:
Both car and counterweight for rated speed over 200 ft./min.
2
The final switch:
only operates if other controls fail
3
The purpose of the governor is to:
cause the power to be removed and the safety to set when overspeed occurs.
4
The purpose of the compensating ropes is to:
Compensate for the change in balance due to the weight of the suspension robes .
5
The brake on the driving machine:
is released, electric power is removed and applied by spring force.
6
The selector serves to:
Provide signal to the controller on car position
7
The governor rope tension sheave:
Is located in the machine room
8
The modern hydraulic elevator receives hydraulic pressure from:
an electric motor driven pump
9
A roped-hydraulic elevator is:
Required to have a car safety
10
The driving machine of a hydraulic elevator is considered to be:
both a and b.
11
The rated speed of modern hydraulic elevator is:
usually less than 200 ft/min.
12
A Direct plunger hydraulic elevator has the plunger connected:
to the car
13
The purpose of the motor generator is to:
provide DC power from AC power
14
If a traction elevator has a sheave on top of the car and counterweight, it is said to be roped:
2:1
15
A roped hydraulic elevator has a maximum ratio of:
1:2
16
‘A’ type safety:
none of the above
17
Standing inside, the elevator at the door jam is on the right it is considered:
right hand application
18
According to the accessibility standard A117.1 a door must reverse and reopen if:
a person or object comes within its path
19
If the closing speed of a horizontally sliding door system is increased:
the kinetic energy will increase
20
The maximum allowable clearance between swinging hoistway doors and car gates is:
4 inches
21
A retractable safety edge (shoe) on a horizontal sliding door:
requires contact to cause the door to stop and reopen
22
Freight elevators usually have:
vertically sliding hoistway entrance doors and vertically sliding car gates.
23
Retiring cams are usually:
must lift before the elevator can move away from the landing
24
The purpose of the traveling cables is to:
provide power and signal to the elevator car
25
The door operator for hydraulic passenger elevators is located:
on the car top