Refrigerator includes two most thermostat (thermostat), are arranged in different ways, functions are performed differently. The first monitors overheating of the compressor, the second - the evaporator temperature. Why certainly apply relay? Simple, reliable. Today we see the mechanical, electrical variety. Thermostat for refrigerator performs call role, triggering a complex mechanism. A signal is heard, the system will remain dead, frost forget!
Where to look for the refrigerator thermostat
The owners of refrigerators with mechanical controls for the thermostat were taken by hand. Not everyone knew. The handle, which installed the temperature mode switch, is mounted on the swivel mechanism thermostat. Formed by two main components that make difficult to mix kit:
- Box with a capacity of executive, control mechanisms.
- Long thin capillary tube (inner diameter of the metal tube of 0.5 mm).
Inside the box in the sealed housing is bellows. Metal bellows cylindrical track changes in ambient pressure change in linear dimensions. To better understand the shape, imagine a metal corrugated hose short length. Unlike the measuring bellows: sealed at both ends, thus sealed. outside the sensing element is compressed when the pressure increases. The design includes a spring, bellows-changing reaction at the applied pressure.
To better understand the purpose, we will make a short excursion into the production processes. Bellows considered measuring elements refrigerators. Element found many uses. In pipelines bellows serves damping element. The ambient temperature rises, the oil transfer line begins to expand in length. The gap is dangerous fire. Vygnet arc line. On-assistance segment of the bellows comes. The accordion is compressed, nothing particularly at elevated temperatures with the conduit does not occur. The situation is repeated, sensing frost.
Manufactured giant bellows (several meters in diameter) made of stainless steel. First extends cylindrical segment. Interesting happens next. The cylinder is inserted into a special machine of impressive dimensions, the press, equipped with a gripper, repeatedly squeezes the bellows, it straightens verified effort. The platform is raised, podium exposes bellows without having marked elastic properties, like a spring. You can stretch, shrink, how did the press, deform.
To balance the external pressure force applied to the bellows for use in the measurement gas is pumped inwardly art. Outside, the external effects are considered to be factors prolong compressing the bellows. Obviously, the thermostat provided with a sensing element will operate at a single temperature. Refrigerators also used simple models. But it is much easier to see the device with a regulator which changes the threshold, making the temperature in the chambers of the corresponding program of the refrigerator.
On a spring scene appears. Spiral bellows cover is secured at both end sealed. Preload spring determines the threshold sensing element. Some bellows provided with one fixed triggering point, others are designed to provide two ranges (camera). Clearly, for the freezing and refrigerating compartments are used dissimilar model.
Work refrigerator thermostat
Examined in detail the actions of the bellows principle reason. Despite the dominance of electronics, thermal relays continue to be equipped with tested elements. No need to install power supplies forming the reduced voltage.
Repair the refrigerator thermostat Stinol have to make about 5 years after purchase. As much of a resource sensitive element produced by a German company.
Durability comes dubious, perhaps, the case to determine the accuracy, reliability. We believe the answer relates to the field of unification. Refrigerator works by forming a four phase states Freon:
It helps to get low temperature. Fridge thermostat provides for the use of freon. Why? Every chlorofluorocarbon gas becomes within the evaporator of the cooling circuit, to easily change the state of aggregation within the capillary tube thermostat, which is mentioned is formed by two components (see. above). Wait a little to indicate the system is filled with refrigerant, completely sealed. The tube is sealed at a free end inside is freon under pressure, allowing fluid to become only the evaporator temperature falls below the threshold. Causing shock drop in system pressure, the bellows is straightened.
The contacts are closed, the control voltage is removed the compressor motor start relay. As a result, the refrigerator is stopped, the temperature ceases to drop. State is maintained until the thermostat threshold for inclusion is passed. Freon inside becomes steam pressure on the bellows is increased, the corrugation is compressed, closes the contacts of the control winding of compressor motor starting. Refrigerator included running until you reached the specified parameters.
Now a few comments on the work of the thermostat. Mentioned above, measured temperature of the evaporator. How does this happen? We are impressed by the sensitive tube length. Incredible length, if necessary, reaches to the floor. All Freon processes involved? Change of aggregate state occurs at the tip to capture a relatively small portion, immediately adjacent to the evaporator. Ensures reliable contact. Typically, the adhesive is used, the top is sealed with sealant. The extra windings stacked in a sealed tube mezhdustennoe space. Underway to install a new thermostat of the refrigerator - to replace the broken one.
Replacing the thermostat for refrigerator under the force of the majority of artists, seen nuance. New thermostat for refrigerator is similar to the old type. Otherwise, the result is very different from the expected. Separate thermostat for refrigerators provide the ability to adjust. Skilled craftsmen manage to resolve the situation with honor. Damage often thermostat indicates fact: a refrigerator temperature not closely correspond to a predetermined. Unscrewing the knob to Off, waiting in vain to hear a click, published by the serviceable thermostat. However, the factor of atypical fully electronic devices discussed below.
The control handle, which for twist-pereschelkivaem temperature regulation directly acts on the refrigerator thermostat spring. A disadvantage of bellows in mechanical complexity ensuring tight regulation. Fielding modes performed steps. For example, a thermostat for domestic refrigerators TAM brand support one or two modes. Difficulties caused by spring adjustment.
Mentioned difficulty settings bellows thermostat for refrigerators. Old proven achievements well enough served more than one generation. Electronic thermal refrigerators allow flexibility to monitor behavior of the structure, provides ample opportunities of adjustment modes.
The sensitive element is a special resistor thyristor. The keys are formed of power transistors, there is a possibility to use ordinary relay. The lack of electronic thermostat for refrigerators limited excessive power, but believe far more important than longevity.
Convenient electronic thermostat in refrigerators equipped with linear (piston) compressors. It is not a separate type of engine, rather a way to manage. Long been a pursuit of secondary parameters of refrigerators:
- Energy consumption.
- Noise level.
New models were equipped with first inverter compressor and then introduced linear. Work without interruption, maintaining the temperature at a predetermined level. Theoretically mode exit noisy in practice is obtained: the compressor operates at half strength, behaves much quieter.
Adjusting the thermostat in the refrigerator thin sensor - responsive to the linear compressor worked. Electronics provides such opportunities.
Thermal refrigerator compressor discussed later.