7-4.Temperature Control
Operating principle |
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A temperature control is used on all refrigerators and | Put the probe of the ohmmetor to the terminal | ||||
freezers to regulate the operation of compressor and | of the temperature control, and check for the | ||||
thus maintain desired food temperatures. | opening and closing of the contacts by turning | ||||
The temperature control consists primarily of a | the knob ON and OFF. | ||||
capillary and billows assembly , a set of normally |
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closed contacts, and a mechanical linkage. |
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Pressure within the gas- charged capillary | tube and |
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billows assembly responds to temperature | sensed |
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at the sensing bulb. |
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Rising temperature causes the pressure to | increase |
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and expand the |
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The expanded billows actuates the linkage which |
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allows contracts to close. |
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When the temperature drops , | the billows contacts |
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due to a decrease in pressure | and the |
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of the linkage opens the contacts. |
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