Deck 17: Commercial and Industrial Air-Conditioning Control Systems

Question 1

Low voltage (24 volts) will not effectively energize some of the large control components that are used in larger systems; therefore, line voltage control systems are used.

Answer 1

True

Question 2

Direct digital control uses a(n) ____________________, which acts as a digital controller.

Answer 2

microprocessor

Question 3

Some commercial and industrial systems use ____________________ to cool water and supply it to chilled water coils in the air flow.

Answer 3

water chillers

Question 4

Many commercial and industrial complexes use a(n) ____________________ to heat water that is supplied to heat transfer devices that condition the air in a structure or zone.

Question 5

The ____________________ packaged unit is built in one unit, much like the air-cooled packaged unit with a remote condenser, except that the condenser is also mounted with the unit.

Question 6

In pneumatic control systems, the ____________________ is the device that senses the desired temperatures and relays them to the controller by supplying specific air pressures representing a specific temperature.

Question 7

What are the different sections of multi-zone roof top units?

Question 8

Water chillers require a(n) ____________________ in the chiller control circuit to ensure that the chilled water pump is operating before the water chiller refrigeration unit operates.

Question 9

Almost all control systems use a(n) ____________________ to control the temperature within a given structure, space, or zone.

Question 10

Why do water-cooled condensing units require an interlock in the condensing unit control circuit?

Question 11

The pressure switch is used to start the compressor on most systems.

Question 12

The ____________________ system uses air to transmit the signal from the sensor to the controller and on to the controlled device.

Question 13

Most large commercial and industrial conditioned air systems use large ____________________ to supply the air flow that is needed to condition the structure.

Question 14

How are elements represented in the direct digital control process?

Question 15

What two methods are used to start three-phase compressors on large systems?

Question 16

An across-the-line type of motor starting requires several contactors.

Question 17

What did early commercial and industrial control systems use to maintain the temperature in a structure, zone, or room?

Question 18

The multi-zone roof top units are usually custom manufactured for a specific application with a specific number of zones.

Question 19

____________________ is the method that is used to vary the capacity of the compressor as the load increases and decreases.

Question 20

Commercial and industrial air-cooled packaged units can be mounted on the outside of a structure on ground level and through an air delivery system supplying conditioned air to the structure.