Deck 12: Ventilating Air Conditioning and Other Facilities

Question 1

In most instances, the rated-load current is at least equal to 64.1 percent of the hermetic refrigerant motor-compressor's ____ current.

A) maximum continuous
B) direct drive
C) branch-circuit selection
D) oscillating

Answer 1

A

Question 2

The current draw of a precipitator is ____.

A) zero
B) very low
C) very high
D) widely variable and dependent on level of pollution

Answer 2

B

Question 3

The manufacturer determines the ____ by multiplying the rated-load current, or the branch-circuit selection current of the hermetic refrigerant motor-compressor, by 125 percent.

A) maximum continuous current
B) maximum overcurrent
C) maximum circuit ampacity
D) minimum circuit ampacity

Answer 3

D

Question 4

What precautions must be taken when installing drive belts?

Question 5

When hermetic refrigerant motor-compressors are designed to operate continuously at currents greater than 156 percent of the rated-load current, the nameplate is marked with ____ current.

A) maximum continuous
B) direct drive
C) branch-circuit selection
D) oscillating

Question 6

The correct tension for a belt in the cooling unit drive can be determined from the ____.

A) maximum continuous current
B) rated-load current
C) motor manufacturer's literature
D) nameplate

Question 7

Low-pressure refrigerant flows through the ____ to provide cooling for the motor of a hermetically sealed compressor.

A) valves
B) rotor
C) load
D) stator winding

Question 8

Whenever the specific area is cooled to the desired temperature, a(n) ____ opens the control circuit to the motor controller and the air movement stops until the area again requires cooling.

A) fan coil
B) thermostat
C) fin tube coil
D) overload protector

Question 9

How are pollutants actually trapped by the precipitator?

Question 10

The exhaust blower unit consists of a three-horsepower, three-phase, 208-volt motor driving a propeller-type fan through a(n) ____ drive.

A) V-belt
B) direct
C) O-ring
D) conveyer

Question 11

The ____ current is determined by the manufacturer of the hermetic refrigerant motor compressor by testing at rated refrigerant pressure, temperature conditions, and voltage.

A) maximum continuous
B) direct drive
C) rated-load
D) oscillating

Question 12

In the precipitator, wires made of which metal give the particles a positive charge?

A) aluminum
B) palladium
C) tungsten
D) silver

Question 13

What is the basic construction of a precipitation unit?

Question 14

The main parts of a precipitator are the ____, collector cells, and power supply.

A) fin tube
B) ionizer
C) cooler
D) oscillator

Question 15

What overload protection is required for the motors of the fan coil units in the cooling equipment?

Question 16

One method of removing oil mist is by the use of ____ units.

A) precipitation
B) coolant
C) rotor
D) stator

Question 17

What is the maximum deflection force in pounds for a belt in the cross-section class D?

A) 2.5
B) 6
C) 13
D) 25

Question 18

What is oil mist and why is it detrimental?

Question 19

A(n) ____ converts high-voltage ac into high-voltage dc.

A) rectifier
B) transistor
C) capacitor
D) inductor

Question 20

The ____ protective device is determined by multiplying the rated-load current, or the branch-circuit selection current of the hermetic refrigerant motor-compressor, by 225 percent and then adding all concurrent loads such as electric heaters, motors, and so on.

A) branch-circuit
B) rated-load
C) maximum continuous current
D) maximum overcurrent