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Bimetallic thermostat type
Temperature changes can cause a bimetallic strip to expand or contract in accordance with changes in temperature. These thermostats are designed for control of heating and cooling in air-conditioning units, refrigerated warehouses, hothouses, fan coil units, explosion coils, and similar devices. This type is used in most homes for management Central air-conditioning and Central heating.
Fig. 14-14 shows how a bimetallic strip thermostat works. Two metal, each of which has a different coefficient of expansion, welded together, forming a bimetallic unit, or blade. With the blade securely fastened at one end of the chain is formed and contact points closed. It allows the passage of electric current through the closed points. Because electric current and heat in its passage through the bimetallic paintings, metals in the blades begin to grow. Nevertheless, they continue to expand at a different rate. Metals in the blade so that the one with the large expansion ratio is placed at the bottom of the device. After some time, the operating temperature is reached and contact points are separated from each other.
This disables the unit from power supply.
After a short period of time, please contact your blade will again be cool to call a contact point to join, thereby restoring the chain and permissions the current time to bring in the chain. The cycle repeats again and again. Thus, bimetal thermostat temperature prevents grow too high or falling too low.
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