unit 13 controls

When a control is required to control space or product temperature, it is called a ____.

• safety device

• thermostat

• pressure control

• speed control

A thermal system overload may occur if a specific electrical or mechanical component is not cooled properly, resulting in ____.

• underload

• overheating

• failure

• explosion

The control that stops the condensing unit if the head pressure climbs too high is classified as a ____.

• safety control

• thermostat

• temperature control

• speed control

The automatic control of a system is intended to ____.

• maintain the working conditions of the equipment manually.

• maintain stable or constant conditions with a controllable device

• prevent overloading situations

• maintain unstable conditions with a controllable device

The overload device mounted in the compressor terminal box would be classified as a ____.

• safety control

• capacitor

• pressure control

• speed control

A thermocouple is a device that ____.

• converts heat to mechanical movement

• records temperature

• converts heat to electrical energy

• couples two temperature controls together

An example of a bimetal device is a ____.

• snap-disc

• mercury-filled tube and diaphragm

• thermistor

• Bourdon tube

The Bourdon tube ____.

• tends to straighten out with an increase in voltage

• tends to curl inward with an increase in vapor pressure

• tends to straighten out with an increase in electrical current

• tends to straighten out with an increase in vapor pressure

The most common control used to sense change in temperature is a ____________________.

• thermostat

• thermistor

• a mercury bulb

• a bimetal strip

The _________________________ relationship is applied to some controls that are partially filled with liquid.

• inverse

• pressure/temperature

• volts/amps

• love/hate