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14 Cards in this Set
- Front
- Back
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An advantage of an electric control system over pneumatic systems is that: a) the controllers can accept a wide variety of inputs b) they provide better control c) they are simple and easy to install d) the controllers can be used outdoors |
c) they are simple and easy to install |
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In a capacitor type control motor, the rotor and gear train are sealed inside a housing that is partially filled with? |
oil |
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Which of the following types of switching devices are used in conjunction with bimetal strips to control electric circuits? a) open-contact switch b) mercury bulb switch c) snap switch d) all of the above |
d) all of the above |
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A heat anticipator gives a thermostat timed ___________ position action to prevent the room temperature from overshooting. |
two |
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What is the sensing element of a remote bulb thermostat filled with? a) air b) high boiling liquid c) volatile liquid d) heavy oil e) hot water |
c) volatile liquid |
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Which of the following is a controlled device? (choose all correct answers) a) a temperature controller b) a three-way mixing valve controlling the water temperature to a heating system c) a damper motor operating air louvers d) the fuel valve in the supply line to the burner on a boiler e) a pressure controller |
b) a three-way mixing valve controlling the water temperature to a heating system c) a damper motor operating air louvers d) the fuel valve in the supply line to the burner on a boiler |
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One of the essential parts of an electric control system is a/an: a) electric-pneumatic relay b) pneumatic-electric switch c) damper d) compressor e) controller |
e) controller |
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The sensing element of a thermostat reacts to a a) change in room pressure b) change in room temperature c) change in room humidity d) change in room air flow rate e) change in room relative humidity |
b) change in room temperature |
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On/off thermostats are equipped with a/an a) open contact switch b) high temperature switch c) low temperature switch d) high voltage switch e) low voltage switch |
a) open contact switch |
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A humidity controller responds to a change in a) absolute temperature b) barometric pressure c) air moisture content d) air flow rate e) temperature and pressure |
c) air moisture content |
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A device used to give the thermostat a timed, two-position actiaon (to prevent air temperature overshoot) is a a) controller b) heat anticipator c) three-way valve d) bellows e) motor |
b) heat anticipator |
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Pressure controllers can be divided into two classes a) high and low temperature b) high and low pressure c) high and low flow d) inside and outside mounting e) on and off control |
b) high and low pressure |
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Electrical control systems provide control by: (choose all correct answers) a) changing voltage b) a continuous signal c) a digital signal d) changing current e) an analog signal |
a) changing voltage d) changing current |
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In a basic electrical control system the device that senses a drop in air temperature is called the: a) final controlled device b) pneumatic temperature sensor c) humidistat d) thermostat e) regulator |
d) thermostat |
