Unit 16

A ____ reacts to stop, start, or modulate the flow of water, air, or refrigerant to the system or conditioned space

• controlled device
• sensor
• controller
• none of the above

All control systems can be subdivided into ____, no matter how many controls there are.

• control loops
• throttle loops
• control segments
• sensor segments

____ control systems were used before electronics.

• Pneumatic
• Manual
• Digital
• Mechanical

Pneumatic controls must have a permanent air supply that is ____.

• clean and dry
• warm and dry
• clean and moist
• clean and warm

Most system compressors provide ____ psig of air pressure to the storage tank.

• 100 to 125
• 90 to 100
• 90 to 125
• 100 to 150

In most system compressors, the compressors are controlled with a ____.

• pressure switch
• heat switch
• limiter
• governor

A ____ is either in the pressure reducer or in the downstream side of the system to ensure that the control air pressure does not exceed about 30 psig.

• relief valve
• blowback valve
• pulldown valve
• pressure valve

In a(n) ____ loop, all changes happen within the loop.

• closed
• open
• modified-closed
• modified-open

A device called a ____ is used to control the large volume of air in an air conditioning system.

• pilot positioner
• pilot lockout
• pilot fixator
• pilot engagement

The pilot positioner has a main air supply that is governed by the ____.

• internal diaphragm
• internal switch
• internal lockout
• internal float