Chapter 16

A(n) ____ element opens an electrical circuit when the temperature rises

Below-atmospheric-pressure

Which type of bimetal device expands or contracts and tilts a mercury switch that serves as the electrical contact between wires?

Bourdon tube

The term for the present condition in a conditioned space is the ____

Control point

A control system's ____ is the difference between the cut-out value and cut-in value

If affects a systems average temperature

Which type of pressure motor control regulates compressor operation to maintain a specific evaporator pressure?

Low pressure motor control

If the low side pressure drops below a safe limit due to refrigerant loss or an evaporator freeze up, a(n)______switches off the compressor motor.

Low pressure safety control

Sometimes called error, the deviation between set point and control point is the ___

Offset

Which of the following device does not operate on electromagnetic principles?

PTC relay

The set of numbers between and including a control system's cut-in and cut-out values is called the systems

Range

In control systems, the desired condition is called the ____

Set point

The type of circuit diagram that shows the components and connections arranged in the order that they activate during circuit operation is a ______ diagram

ladder

The type of circuit diagram that show the approximate physical location of components in relation to each other is a _____________ diagram

pictorial

The temperature or pressure value at which a device begins operation is it

Cut-in

The temperature or pressure value at which a device ceases operation is it

Cut-out

A____relay is operated by the change in current flow through a motor run winding

Current

Sensing bulbs typically use a bellows or ___ to open and close contact points as their internal pressure changes

Diaphragm

A control system's ____ is the difference between the cut-out value and cut-in value

Differential

Reducing a systems cut-out temperature without changing its cut-in temperature is an example of ____.

Differential adjustment

If a cooling system 's cut-in temperature is decreased, but its cut-out temperature stays the same, which of the following is true?

The average temperature decreases

The three main components used in a HVACR control system

controlled device, controllor, and sensor

Which of the following devices is not used as a temperature sensor in thermostatic motor controls?

fuse