Deck 15: Flow Switches

Question 1

Figure 15-6


In the accompanying diagram, the circuit is designed to control the operation of a(n) ____________________.

Answer 1

air compressor

Question 2

Why are air flow switches often used in air conditioning and refrigeration circuits?

Answer 2

Air flow switches are often used in air conditioning and refrigeration circuits to give a positive indication that the evaporator or condenser fan is operating before the compressor is permitted to start.

Question 3

In the accompanying figure, what happens when the pressure switch contact closes?

Answer 3

When the pressure switch contact closes, power is supplied to the lube oil pump relay. The flow switch detects the flow of lubricating oil before the compressor is permitted to start.

Question 4

Figure 15-6


In the accompanying diagram, a(n) ____________________ controls the operation of the compressor.

Question 5

Figure 15-2



In the accompanying figure, a circuit like one for refrigeration or air conditioning is shown.  When the thermostat contact closes what happens?

Question 6

Air flow switches are often called ____________________.

Question 7

Figure 15-6


In the accompanying diagram, the red light indicates the flow of oil.

Question 8

Regardless of whether a flow switch is intended to detect the movement of air or liquid, the NEMA symbol for both is the same.

Question 9

The air flow switch is constructed from a snap action micro switch.

Question 10

Flow switches are used to detect the ____________________ of air or liquid through a duct or pipe.

Question 11

Flow switches are used to control high current loads.

Question 12

Figure 15-2



In the accompanying figure, why is there a dashed line around the condenser fan motor and overload symbol, and around the evaporator fan motor and overload symbol?

Question 13

Regardless of the type of flow switch used, a single pole double throw micro switch is generally contained.

Question 14

Explain how a snap action micro switch for an air flow switch works.

Question 15

The air flow switch is constructed from a(n) ____________________ micro switch.