HVAC Control Circuits Quiz Objective 2

What is a common feature between HVAC controllers and refrigeration controllers?

• 24 hour, 7 day internal timer

• Use of a semiconductor sensor

• Higher voltage 120/240VAC

• More user friendly interface

Answer explanation

The correct answer is the use of a semiconductor sensor, which is a common feature between HVAC controllers and refrigeration controllers.

What is a difference between HVAC single zone thermostat and refrigeration thermostat?

• More user friendly interface

• 24 hour, 7 day internal timer

• Use of a semiconductor sensor

• Higher voltage 120/240VAC

Answer explanation

The difference between HVAC single zone thermostat and refrigeration thermostat is the more user friendly interface.

What is the purpose of an Integrated Modular Controller (IMC) in HVAC systems?

• To provide demand ventilation to a zone or building

• To control the unit on a single PCB

• To measure the space temperature

• To operate the economizer

Answer explanation

The purpose of an Integrated Modular Controller (IMC) in HVAC systems is to control the unit on a single PCB.

What do LED's indicate in an Integrated Modular Controller (IMC)?

• The space temperature

• The status of various components

• The outdoor air sensor

• The mixed air sensor

Answer explanation

LED's in an Integrated Modular Controller (IMC) indicate the status of various components, not the space temperature, outdoor air sensor, or mixed air sensor.

What is the function of an Economizer Module in HVAC systems?

• To measure the space temperature

• To control the unit on a single PCB

• To operate the economizer

• To provide demand ventilation to a zone or building

Answer explanation

The function of an Economizer Module in HVAC systems is to operate the economizer.

What adjustments are normally found in an Economizer Module?

• The change over set point in enthalpy gradients

• The mixed air sensor

• The status of various components

• The outdoor air sensor

Answer explanation

The adjustments normally found in an Economizer Module include the change over set point in enthalpy gradients.

What is the likely voltage used in HVAC thermostats?

• 48VDC

• 12VDC

• 120/240VAC

• 24VAC

Answer explanation

HVAC thermostats likely use 24VAC as the voltage.

What is the likely voltage used in refrigeration thermostats?

• 120/240VAC

• 48VDC

• 24VAC

• 12VDC

Answer explanation

Refrigeration thermostats typically use 120/240VAC as the likely voltage.

What is the purpose of relay contact points in a single zone thermostat?

• To interface with the electrical control system

• To control the unit on a single PCB

• To provide demand ventilation to a zone or building

• To measure the space temperature

Answer explanation

The purpose of relay contact points in a single zone thermostat is to interface with the electrical control system, allowing the thermostat to control the HVAC unit.

What is the purpose of dip switches in an Integrated Modular Controller (IMC)?

• To provide demand ventilation to a zone or building

• To configure the unit

• To control the unit on a single PCB

• To measure the space temperature

Answer explanation

Dip switches in an Integrated Modular Controller (IMC) are used to configure the unit, allowing for customization and adjustment of settings.