1. A flow switch either closes or opens a set of gates.
a. True
b. False
2. Typical applications of flow switches are commonly found in the chemical and petroleum industries.
a. True
b. False
3. The insulation of the wire leading to the switches must be adequate to withstand the high pressure of the liquid inside
the pipe.
a. True
b. False
4. You can consult the NEC®
for insulation temperature ratings.
a. True
b. False
5. Air condition and heating circuits often use timed contacts that are self-contained and do not require a coil for
operation. Their time delay is preset and cannot be adjusted.
a. True
b. False
Name: Class: Date:
Unit 12 Flow Switches
6. A flow switch is a device that can be inserted in a pipe so that when liquid or air flows against a part of the device
called a ____, a switch is activated.
a. pilot tube b. Bourdon tube
c. bulb d. paddle
7. In general, a flow switch contains ____ electrical contacts.
a. either normally open or normally closed
b. only normally open
c. both normally open and normally closed
d. only normally closed
8. A flow switch used with ____ may start a motor when flow occurs, and stop the motor when there is no flow.
a. on-off circuit b. short circuit
c. three-phase circuit d. single-phase circuit
9. A flow switch may be used to detect ____ over the refrigeration coils, stopping the refrigeration compressor and
starting a defrost cycle.
a. insufficient air movement b. insufficient refrigerant
c. excessive air movement d. excessive refrigerant
10. The electrical connections of airflow switches are ____ those of liquid flow switches.
a. very different from b. similar to
c. derived from d. identical to
Name: Class: Date:
Unit 12 Flow Switches