Zero-power-consumption motor starting thermal protector

Abstract

The utility model relates to a zero-power-consumption motor starting thermal protector. The bidirectional silicon controlled rectifier is provided with a bidirectional silicon controlled rectifier first pole, a bidirectional silicon controlled rectifier second pole and a bidirectional silicon controlled rectifier trigger pole. The current transformer is provided with a first pin of a primary coil of the current transformer, a second pin of the primary coil of the current transformer, a first pin of a secondary coil of the current transformer and a second pin of the secondary coil of the current transformer, and the first pin is connected with the first pin of the primary coil of the current transformer. A second pin of a primary coil of the current transformer is connected with a connecting piece, the connecting piece is connected with an N line bank and a second pole of a bidirectional silicon controlled rectifier, a first pole of the bidirectional silicon controlled rectifier is connected with a first pin of a secondary coil of the current transformer and a reed, and the reed is connected with one side of a starting thermistor. The other side of the starting thermistor is connected with a second pin, and a trigger electrode of the bidirectional silicon controlled rectifier is connected with a second pin of a secondary coil of the current transformer.

Description

Technical Field

[0001] This utility model relates to a zero-power motor starter thermal protector, which is mainly used for starting refrigeration compressor motors or other motors and for over-temperature rise and over-current protection. Background Technology

[0002] Currently, the fixed-frequency refrigeration compressors used in refrigerators generally employ single-phase asynchronous motors. A single-phase asynchronous motor typically consists of a rotor and a stator, with the stator composed of a main winding and an auxiliary winding. The auxiliary winding, besides its function of starting the motor, also participates in auxiliary operation during normal motor operation to improve efficiency. Therefore, a complete auxiliary winding circuit can usually be represented by a parallel auxiliary winding operating circuit and an auxiliary winding starting circuit. When the motor is powered on, both the main and auxiliary windings are energized simultaneously. The current flowing through the windings generates an alternating rotating magnetic field on the stator, causing the rotor to begin rotating. As the rotor torque increases, the speed gradually increases. Generally, when the speed reaches 75%-80% or more of the rated speed, the auxiliary winding starting circuit should be disconnected promptly. At this point, the motor can continue to accelerate until it reaches the rated speed and enters normal operation. The connection and disconnection of the auxiliary winding are accomplished by the starter. In addition, a thermal protector is connected in series in the main circuit of the refrigeration compressor. When the refrigeration compressor motor is overcurrent or overheated due to external causes or refrigeration system failure, the thermal protector will activate and cut off the power supply to protect the compressor motor.

[0003] The starters currently used include PTC starters, electronic starters, and current-sensing starters.

[0004] PTC starters utilize the R / T characteristics of PTC thermistors to achieve starting. When the motor starts, because the resistance of the PTC is low at room temperature, the current flowing through the secondary winding is large, causing the PTC to heat up and its resistance to rise rapidly. When the temperature reaches the Curie point, the resistance can reach several thousand ohms or more, reducing the current in the secondary winding circuit to about ten milliamps, thus essentially cutting off the secondary winding. After starting, in order to maintain the high resistance state of the PTC element, a holding current of about ten milliamps still flows through the PTC element. This holding current will generate about 3W of power consumption, resulting in a large waste of electrical energy. To reduce this power consumption, the current approach is to add a bidirectional thyristor and a trigger PTC that controls the on / off state of the bidirectional thyristor to the PTC starter. The working principle is to use the trigger current of the series circuit of the trigger PTC and the trigger junction of the bidirectional thyristor to control the main switch of the bidirectional thyristor to delay the turn-off of the starting PTC circuit, thus eliminating the power consumption of about 3W generated by starting the PTC. However, the trigger PTC still needs to maintain a small current in the trigger circuit of the bidirectional thyristor, which will still generate a power consumption of about 0.5W.

[0005] The working principle of an electronic starter is to use electronic circuits to control the on / off state of the starting circuit switch. Currently used electronic starters generally have complex circuit designs and many electronic components, resulting in higher manufacturing costs and increased reliability risks. They also consume a certain amount of power, so their application in the market is not very widespread.

[0006] The working principle of a current-sensing starter is to sample the current change in the main winding of the motor and, using the principle of current induction, control the opening and closing of a switch connected in series with the auxiliary winding. At the start of startup, the main winding starting current is large, controlling the opening of the starting circuit switch; after the motor starts, the main winding current decreases, controlling the closing of the starting circuit switch, completing the entire starting process. Starters using mechanical contacts in the starting circuit switch are called counterweight starters, while those using electronic switches are called inductive contactless starters, which generally use bidirectional thyristors. Contactless starters can effectively improve the problems of short lifespan and explosion-proof issues caused by arcing from mechanical contacts. However, existing inductive contactless starters still have problems such as unreasonable component layout, inconvenient wiring, and cumbersome installation. Utility Model Content

[0007] The purpose of this utility model is to overcome the above-mentioned shortcomings in the existing technology and provide a zero-power motor starter thermal protector with a reasonable structural design, so as to achieve the purpose of compact design, convenient additional electrical connection and improved installation efficiency.

[0008] The technical solution adopted by this utility model to solve the above problems is as follows: This zero-power motor starter thermal protector includes a thermal protector and a starter. The starter includes a base, a PE terminal block, an L terminal block, an N terminal block, a stop bar, a first pin, a second pin, a starting thermistor, a spring, a bidirectional thyristor, a connecting piece, and a cover plate. Its structural feature is that the starter also includes a current transformer. The bidirectional thyristor is provided with a first bidirectional thyristor pole, a second bidirectional thyristor pole, and a trigger pole. The current transformer is provided with a first pin of the primary coil of the current transformer and a primary winding of the current transformer. The primary coil has a second pin, a secondary coil has a first pin, and a secondary coil has a second pin. The first pin is connected to the first pin of the primary coil of the current transformer. The second pin of the primary coil of the current transformer is connected to a connecting piece. The connecting piece is connected to the N-terminal block and the second electrode of the bidirectional thyristor. The first electrode of the bidirectional thyristor is connected to the first pin of the secondary coil of the current transformer and a spring. The spring is connected to one side of the starting thermistor. The other side of the starting thermistor is connected to the second pin. The trigger electrode of the bidirectional thyristor is connected to the second pin of the secondary coil of the current transformer.

[0009] Furthermore, the baffle, the first pin, the second pin, the starting thermistor, the spring, the bidirectional thyristor, the current transformer, and the connecting piece are all disposed in the cavity formed by the base and the cover plate.

[0010] Furthermore, the PE terminal block, L terminal block, and N terminal block are all disposed within the outer cavity of the base.

[0011] Furthermore, the N terminal block is provided with an N terminal block insert end, an N terminal block threaded end, and an N terminal block connection end. The N terminal block connection end is disposed on the N terminal block threaded end and is connected to the connecting piece.

[0012] Furthermore, the first pin is provided with a first pin socket, a first pin connecting piece, a first pin connecting arm, and a first pin connecting slot. The first pin socket and the first pin connecting piece are located at one end of the first pin connecting arm, and the first pin connecting slot is located at the other end of the first pin connecting arm. The first pin connecting slot is connected to the first pin of the primary coil of the current transformer.

[0013] Furthermore, the second pin is provided with a second pin socket, a second pin connecting piece, a second pin connecting arm, and a second pin connecting end. The second pin socket and the second pin connecting piece are located at one end of the second pin connecting arm, and the second pin connecting end is located at the other end of the second pin connecting arm. The second pin connecting end is connected to the other side of the starting thermistor.

[0014] Furthermore, the reed is provided with a first reed connection slot, a second reed connection slot, and a reed spring. The first and second reed connection slots are located above the reed, and the reed spring is located on one side of the reed. The first reed connection slot is connected to the first electrode of the bidirectional thyristor, the second reed connection slot is connected to the first pin of the secondary coil of the current transformer, and the reed spring is connected to one side of the starting thermistor.

[0015] Furthermore, the connecting piece is provided with a connecting piece connecting end, a connecting piece connecting arm, a first connecting slot, and a second connecting slot. The connecting piece connecting end is located at one end of the connecting piece, and the connecting piece connecting arm is located at the other end of the connecting piece. The two ends of the connecting piece connecting arm are respectively provided with a first connecting slot and a second connecting slot. The connecting piece connecting end is connected to the N terminal block, the first connecting slot is connected to the second pin of the primary coil of the current transformer, and the second connecting slot is connected to the second electrode of the bidirectional thyristor.

[0016] Furthermore, the base is provided with a PE terminal block mounting cavity, an L terminal block mounting cavity, an N terminal block mounting cavity, a first pin mounting cavity, a second pin mounting cavity, a connecting piece mounting cavity, a retaining bar mounting cavity, a starting thermistor mounting cavity, a spring mounting cavity, a bidirectional thyristor mounting cavity, a current transformer mounting cavity, a base first locking hole, a base second locking hole, a thermal protector mounting cavity, and a thermal protector mounting hook. The PE terminal block, L terminal block, N terminal block, first pin, second pin, connecting piece, and retaining bar are also included. The starting thermistor, spring, bidirectional thyristor, and current transformer are respectively installed in the PE terminal block mounting cavity, L terminal block mounting cavity, N terminal block mounting cavity, first pin mounting cavity, second pin mounting cavity, connecting piece mounting cavity, retaining strip mounting cavity, starting thermistor mounting cavity, spring mounting cavity, bidirectional thyristor mounting cavity, and current transformer mounting cavity. The thermal protector is installed in the thermal protector mounting cavity through the thermal protector mounting hook. The base first and base second locking holes are engaged with the cover plate.

[0017] Furthermore, the cover plate is provided with a cover plate M-hole, a cover plate S-hole, a cover plate first hook, a cover plate second hook, a first pin hole positioning cavity, a second pin hole positioning cavity, a stop bar limiting boss, a starting thermistor limiting boss, a spring limiting boss, a current transformer limiting boss, and a connecting piece limiting platform. The cover plate M-hole and the first pin hole positioning cavity cooperate with the first pin, the cover plate S-hole and the second pin hole positioning cavity cooperate with the second pin, the stop bar limiting boss, the starting thermistor limiting boss, the spring limiting boss, the current transformer limiting boss, and the connecting piece limiting platform cooperate with the stop bar, the starting thermistor, the spring, the current transformer, and the connecting piece, respectively, and the cover plate first hook and the cover plate second hook engage with the base, and the cover plate first hook and the cover plate second hook engage with the base first hook and the base second hook, respectively.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. By sampling the current signal of the main winding circuit using a current transformer, the on / off switching of the bidirectional thyristor can be triggered, which can effectively shut off the heat and power consumption generated by the starting PTC chip. The power consumption of the current sampling system can be as low as milliwatts during normal motor operation, close to "zero power consumption", thereby further improving energy efficiency. In addition, the number of components is small, the circuit layout is reasonable, safe and reliable, ensuring the motor starting function and improving the reliability of motor starting performance.

[0020] 2. The PE terminal block, L terminal block, and N terminal block can meet the connection and transfer of wires for working capacitors, indicator lights, thermostats, electrical control boards and other devices in household refrigeration appliances, without affecting the normal operation of the zero-power motor starter thermal protector.

[0021] 3. The combination of thermal protector and mutual inductor low-power starter improves the installation efficiency of electrical accessories and makes the installation and use safer and more reliable. Attached Figure Description

[0022] Figure 1 This is an exploded structural diagram of the zero-power motor starter thermal protector according to an embodiment of the present invention.

[0023] Figure 2 This is a three-dimensional structural diagram of the zero-power motor starter thermal protector according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the zero-power motor starter thermal protector of this utility model without the cover plate.

[0025] Figure 4 This is a schematic diagram of the internal structure of the zero-power motor starter thermal protector according to an embodiment of this utility model.

[0026] Figure 5 This is a three-dimensional structural diagram of the cover plate according to an embodiment of the present utility model.

[0027] Figure 6 This is a three-dimensional structural diagram of the cover plate according to an embodiment of the present utility model.

[0028] Figure 7 This is a three-dimensional structural diagram of the base according to an embodiment of the present utility model.

[0029] Figure 8 This is a three-dimensional structural diagram of the base according to an embodiment of the present utility model.

[0030] Figure 9 This is a three-dimensional structural diagram of the N-terminal block according to an embodiment of the present invention.

[0031] Figure 10 This is a three-dimensional structural diagram of the first pin of an embodiment of the present utility model.

[0032] Figure 11 This is a three-dimensional structural diagram of the second pin in an embodiment of the present invention.

[0033] Figure 12 This is a three-dimensional structural diagram of the reed according to an embodiment of the present invention.

[0034] Figure 13 This is a three-dimensional structural schematic diagram of a bidirectional thyristor according to an embodiment of the present invention.

[0035] Figure 14 This is a three-dimensional structural diagram of the current transformer according to an embodiment of the present invention.

[0036] Figure 15This is a three-dimensional structural diagram of the connecting piece according to an embodiment of the present utility model.

[0037] Figure 16 This is a schematic diagram of the assembly process of the starting thermal protector according to an embodiment of the present utility model.

[0038] In the diagram: 1. Base; 2. PE terminal block; 3. L terminal block; 4. N terminal block; 5. Stop bar; 6. First pin; 7. Second pin; 8. Starting thermistor; 9. Spring; 10. Bidirectional thyristor; 11. Current transformer; 12. Connecting piece; 13. Cover plate; 14. Thermal protector.

[0039] PE terminal block mounting cavity 1-1, L terminal block mounting cavity 1-2, N terminal block mounting cavity 1-3, first pin mounting cavity 1-4, second pin mounting cavity 1-5, connecting piece mounting cavity 1-6, retaining strip mounting cavity 1-7, starting thermistor mounting cavity 1-8, spring plate mounting cavity 1-9, bidirectional thyristor mounting cavity 1-10, current transformer mounting cavity 1-11, base first locking hole 1-12, base second locking hole 1-13, thermal protector mounting cavity 1-14, thermal protector mounting hook 1-15.

[0040] N-terminal connector plug end 4-1, N-terminal connector threaded end 4-2, N-terminal connector connection end 4-3

[0041] First pin socket 6-1, first pin connecting tab 6-2, first pin connecting arm 6-3, first pin connecting slot 6-4

[0042] Second pin socket 7-1, second pin connecting tab 7-2, second pin connecting arm 7-3, second pin connecting end 7-4

[0043] Spring contacts connect to slot 1 (9-1), spring contacts connect to slot 2 (9-2), and spring contacts (9-3).

[0044] The first electrode of the bidirectional thyristor is 10-1, the second electrode is 10-2, and the trigger electrode is 10-3.

[0045] Current transformer primary coil first pin 11-1, current transformer primary coil second pin 11-2, current transformer secondary coil first pin 11-3, current transformer secondary coil second pin 11-4

[0046] Connecting end 12-1, connecting arm 12-2, connecting slot 12-3 (first connecting slot), connecting slot 12-4 (second connecting slot)

[0047] Cover plate M socket 13-1, cover plate S socket 13-2, cover plate first hook 13-3, cover plate second hook 13-4, first pin socket positioning cavity 13-5, second pin socket positioning cavity 13-6, stop bar limiting boss 13-7, starting thermistor limiting boss 13-8, spring limiting boss 13-9, current transformer limiting boss 13-10, connecting piece limiting platform 13-11.

[0048] Thermal protector electrical connection terminal 14-1, thermal protector pin 14-2, Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0050] Example

[0051] See Figures 1 to 16 As shown in the accompanying drawings, the structures, proportions, sizes, etc., depicted in this specification are merely for illustrative purposes to aid those skilled in the art and to provide a clear understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the use of terms such as "upper," "lower," "left," "right," "middle," and "one" in this specification is solely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0052] The zero-power motor starter thermal protector in this embodiment includes a thermal protector 14 and a starter. The starter includes a base 1, a PE terminal block 2, an L terminal block 3, an N terminal block 4, a baffle 5, a first pin 6, a second pin 7, a starting thermistor 8, a spring 9, a bidirectional thyristor 10, a current transformer 11, a connecting piece 12, and a cover plate 13. The baffle 5, the first pin 6, the second pin 7, the starting thermistor 8, the spring 9, the bidirectional thyristor 10, the current transformer 11, and the connecting piece 12 are all disposed in the cavity formed by the base 1 and the cover plate 13. The PE terminal block 2, the L terminal block 3, and the N terminal block 4 are all disposed in the outer cavity of the base 1.

[0053] In this embodiment, the bidirectional thyristor 10 is provided with a first bidirectional thyristor electrode 10-1, a second bidirectional thyristor electrode 10-2, and a trigger electrode 10-3. The current transformer 11 is provided with a first pin 11-1 of the primary coil, a second pin 11-2 of the primary coil, a first pin 11-3 of the secondary coil, and a second pin 11-4 of the secondary coil. The first pin 6 is connected to the first pin 11-1 of the primary coil. Connect the second pin 11-2 of the primary coil of the current transformer to the connecting piece 12. The connecting piece 12 is connected to the N terminal block 4 and the second pole 10-2 of the bidirectional thyristor. The first pole 10-1 of the bidirectional thyristor is connected to the first pin 11-3 of the secondary coil of the current transformer and the spring 9. The spring 9 is connected to one side of the starting thermistor 8. The other side of the starting thermistor 8 is connected to the second pin 7. The trigger pole 10-3 of the bidirectional thyristor is connected to the second pin 11-4 of the secondary coil of the current transformer.

[0054] In this embodiment, the N terminal block 4 is provided with an N terminal block insert end 4-1, an N terminal block threaded end 4-2, and an N terminal block connection end 4-3. The N terminal block connection end 4-3 is disposed on the N terminal block threaded end 4-2 and is connected to the connection piece 12.

[0055] In this embodiment, the first pin 6 is provided with a first pin socket 6-1, a first pin connecting piece 6-2, a first pin connecting arm 6-3, and a first pin connecting slot 6-4. The first pin socket 6-1 and the first pin connecting piece 6-2 are located at one end of the first pin connecting arm 6-3, and the first pin connecting slot 6-4 is located at the other end of the first pin connecting arm 6-3. The first pin connecting slot 6-4 is connected to the first pin 11-1 of the primary coil of the current transformer.

[0056] In this embodiment, the second pin 7 is provided with a second pin socket 7-1, a second pin connecting piece 7-2, a second pin connecting arm 7-3, and a second pin connecting end 7-4. The second pin socket 7-1 and the second pin connecting piece 7-2 are located at one end of the second pin connecting arm 7-3, and the second pin connecting end 7-4 is located at the other end of the second pin connecting arm 7-3. The second pin connecting end 7-4 is connected to the other side of the starting thermistor 8.

[0057] In this embodiment, the reed 9 is provided with a reed connection slot 9-1, a reed connection slot 9-2, and a reed spring 9-3. The reed connection slots 9-1 and 9-2 are located above the reed 9, and the reed spring 9-3 is located on one side of the reed 9. The reed connection slot 9-1 is connected to the first electrode 10-1 of the bidirectional thyristor, the reed connection slot 9-2 is connected to the first pin 11-3 of the secondary coil of the current transformer, and the reed spring 9-3 is connected to one side of the starting thermistor 8.

[0058] In this embodiment, the connecting piece 12 is provided with a connecting piece connecting end 12-1, a connecting piece connecting arm 12-2, a first connecting slot 12-3, and a second connecting slot 12-4. The connecting piece connecting end 12-1 is located at one end of the connecting piece 12, and the connecting piece connecting arm 12-2 is located at the other end of the connecting piece 12. The two ends of the connecting piece connecting arm 12-2 are respectively provided with the first connecting slot 12-3 and the second connecting slot 12-4. The connecting piece connecting end 12-1 is connected to the N terminal block 4, the first connecting slot 12-3 is connected to the second pin 11-2 of the primary coil of the current transformer, and the second connecting slot 12-4 is connected to the second electrode 10-2 of the bidirectional thyristor.

[0059] In this embodiment, the base 1 is provided with PE terminal block mounting cavity 1-1, L terminal block mounting cavity 1-2, N terminal block mounting cavity 1-3, first pin mounting cavity 1-4, second pin mounting cavity 1-5, connecting piece mounting cavity 1-6, baffle mounting cavity 1-7, starting thermistor mounting cavity 1-8, spring mounting cavity 1-9, bidirectional thyristor mounting cavity 1-10, current transformer mounting cavity 1-11, base first locking hole 1-12, base second locking hole 1-13, thermal protector mounting cavity 1-14 and thermal protector mounting hook 1-15, PE terminal block 2, L terminal block 3, N terminal block 4, first pin 6, second pin 7, connecting piece 12, and baffle 5. The starting thermistor 8, spring 9, bidirectional thyristor 10, and current transformer 11 are respectively installed in the PE terminal block mounting cavity 1-1, L terminal block mounting cavity 1-2, N terminal block mounting cavity 1-3, first pin mounting cavity 1-4, second pin mounting cavity 1-5, connecting piece mounting cavity 1-6, stop bar mounting cavity 1-7, starting thermistor mounting cavity 1-8, spring 9, bidirectional thyristor mounting cavity 1-10, and current transformer mounting cavity 1-11. The thermal protector 14 is installed in the thermal protector mounting cavity 1-14 through the thermal protector mounting hook 1-15. The base first locking hole 1-12 and the base second locking hole 1-13 are engaged with the cover plate 13.

[0060] In this embodiment, the cover plate 13 is provided with cover plate M insertion hole 13-1, cover plate S insertion hole 13-2, cover plate first hook 13-3, cover plate second hook 13-4, first pin insertion hole positioning cavity 13-5, second pin insertion hole positioning cavity 13-6, stop bar limiting boss 13-7, starting thermistor limiting boss 13-8, spring limiting boss 13-9, current transformer limiting boss 13-10, and connecting piece limiting platform 13-11. Cover plate M insertion hole 13-1 and first pin insertion hole positioning cavity 13-5 cooperate with the first pin 6, and cover plate S insertion hole 13-2 and second pin insertion hole positioning cavity 13-6 are provided with the following: The socket positioning cavity 13-6 mates with the second pin 7. The stop bar limiting boss 13-7, the starting thermistor limiting boss 13-8, the spring limiting boss 13-9, the current transformer limiting boss 13-10, and the connecting piece limiting platform 13-11 mate with the stop bar 5, the starting thermistor 8, the spring 9, the current transformer 11, and the connecting piece 12, respectively. The cover plate first hook 13-3 and the cover plate second hook 13-4 are engaged with the base 1. The cover plate first hook 13-3 and the cover plate second hook 13-4 are engaged with the base first locking hole 1-12 and the base second locking hole 1-13, respectively.

[0061] The starter assembly process is as follows:

[0062] 1. When installing the product, first install the current transformer 11 into the current transformer mounting cavity 1-11, and then install the first pin 6 and the connecting piece 12 into the first pin mounting cavity 1-4 and the connecting piece mounting cavity 1-6 respectively. At this time, the first pin connecting slot 6-4 is welded to the first pin 11-1 of the primary coil of the current transformer, and the connecting piece connecting slot 12-3 is welded to the second pin 11-2 of the primary coil of the current transformer.

[0063] 2. Insert the spring 9, the second pin 7, and the starting thermistor 8 into the spring mounting cavity 1-9, the second pin mounting cavity 1-5, and the starting thermistor mounting cavity 1-8 in sequence. At this time, the spring 9-3 is in contact with one side of the starting thermistor 8, and the other side of the starting thermistor 8 is in contact with the second pin connection terminal 7-4. The spring connection slot 9-2 is welded to the first pin 11-3 of the secondary coil of the current transformer. Then, insert the stop bar 5 into the stop bar mounting cavity 1-7. The stop bar 5 locks the spring 9, the starting thermistor 8, and the second pin 7, ensuring stable contact and conductivity of the starting thermistor 8.

[0064] 3. Insert the bidirectional thyristor 10 into the bidirectional thyristor mounting cavity 1-10. Finally, weld the first electrode 10-1, the second electrode 10-2, and the trigger electrode 10-3 of the bidirectional thyristor to the spring contact slot 9-1, the connecting plate slot 12-4, and the second pin 11-4 of the secondary coil of the current transformer, respectively.

[0065] 4. Install and close the cover plate 13 and the base 1. The base 1 first locking hole 1-12 and the base 1 second locking hole 1-13 are respectively engaged with the cover plate 13 first locking hook 13-3 and the cover plate 13 second locking hook 13-4. At this time, the positioning relationship between the cover plate 13 and the related parts is as follows: the first pin insertion hole 6-1 and the second pin insertion hole 7-1 are respectively positioned in the first pin insertion hole positioning cavity 13-5 and the second pin insertion hole positioning cavity 13-6. The stop bar 5, the starting thermistor 8, the spring 9, the current transformer 11, and the connecting piece 12 are respectively positioned in the stop bar limiting boss 13-7, the thermistor limiting boss 13-8, the spring limiting boss 13-9, the current transformer limiting boss 13-10, and the connecting piece limiting platform 13-11.

[0066] 5. Install PE terminal block 2, L terminal block 3, and N terminal block 4 into the PE terminal block mounting cavity 1-1, L terminal block mounting cavity 1-2, and N terminal block mounting cavity 1-3 of the base 1, respectively. Weld the N terminal block connecting end 4-3 and the connecting piece connecting end 12-1.

[0067] 6. After assembling the above low-power starter, install the thermal protector 14 into the thermal protector mounting cavity 1-14. At this time, the thermal protector 14 and the thermal protector mounting hook 1-15 are connected and fixed. The thermal protector electrical connection terminal 14-1 is connected to the external electrical connection. The cover plate M socket 13-1 is connected to the main winding of the motor, and the cover plate S socket 13-2 is connected to the auxiliary winding of the motor.

[0068] After the above steps are completed, a zero-power motor starter thermal protector is formed.

[0069] The working process of the zero-power motor starter thermal protector is as follows:

[0070] In this embodiment, a zero-power motor starter thermal protector is installed in a refrigerator compressor. The starter thermal protector is directly inserted into the compressor's sealed terminal block via the first pin 6-1 (connected to the compressor's M terminal), the second pin 7-1 (connected to the compressor's S terminal), and the thermal protector pin 14-2 (connected to the compressor's C terminal). Simultaneously, an external running capacitor is connected in parallel between the first pin connecting piece 6-2 and the second pin connecting piece 7-2. The power supply N terminal is then connected to the N terminal block pin 4-1 or the N terminal block threaded end 4-2, the power supply L terminal is connected to the thermal protector's electrical connection terminal 14-1, and the grounding wire is connected to the PE terminal block 2. Other electrical connections and transitions in the refrigeration appliance can be made through the PE terminal block 2, the L terminal block 3, and the N terminal block 4.

[0071] At this time, the main winding of the motor and the primary coil of the current transformer 11 are connected in series to form the main winding running circuit. The secondary coil of the current transformer 11 and the first pole 10-1 and the trigger pole 10-3 of the bidirectional thyristor are connected in series to form the bidirectional thyristor triggering circuit. The auxiliary winding of the motor, the starting thermistor 8 and the first pole 10-1 and the second pole 10-2 of the bidirectional thyristor are connected in series to form the auxiliary winding starting circuit.

[0072] After the AC power supply is turned on at terminals L and N, the motor is initially in a stalled state, resulting in a large current flowing through its main winding circuit. This causes a large current to also flow through the primary coil of the current transformer 11. Under the influence of electromagnetic induction, the secondary coil of the current transformer 11 will induce a corresponding proportional current. Given appropriate parameters for the current transformer 11, the induced current in its secondary coil is sufficient to trigger the conduction between the first and second poles of the bidirectional thyristor 10-1 and 10-2. This connects the secondary winding starting circuit, generating a starting current, and the motor begins to run. The starting thermistor 8, connected in series in the starting circuit, operates under the influence of the starting current. When the motor starts, the resistance rises rapidly until it reaches its maximum value. After the motor starts, it enters normal operation. Generally, the operating current of the main winding circuit is much smaller than the stall current at the beginning of power-on. Under the induction of the current transformer 11, the induced current of the secondary coil of the current transformer 11 is also much smaller than that at the beginning of power-on. Under the premise of selecting appropriate parameters for the current transformer 11, the induced current will not trigger the conduction between the first pole 10-1 and the second pole 10-2 of the bidirectional thyristor. The starting circuit of the secondary winding is completely turned off. At this time, the power consumption generated by the sampling system of the current transformer 11 can reach the ultra-low power consumption of milliwatt level, which is close to a "zero power consumption" starter.

[0073] When the mains voltage is too high or the refrigeration system malfunctions, the thermal protector 14 will activate, thereby cutting off the power supply and protecting the compressor motor.

[0074] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. A zero-power-consumption motor starting thermal protector, comprising a thermal protector (14) and a starter, the starter comprising a base (1), a PE wiring strip (2), an L wiring strip (3), an N wiring strip (4), a baffle (5), a first pin (6), a second pin (7), a starting thermal resistor (8), a reed (9), a bidirectional thyristor (10), a connecting sheet (12) and a cover plate (13), characterized in that: The starter further comprises a current transformer (11), the triac (10) is provided with a triac first electrode (10-1), a triac second electrode (10-2) and a triac trigger electrode (10-3), the current transformer (11) is provided with a current transformer primary coil first pin (11-1), a current transformer primary coil second pin (11-2), a current transformer secondary coil first pin (11-3) and a current transformer secondary coil second pin (11-4), the first pin (6) is connected with the current transformer primary coil first pin (11-1), the current transformer primary coil second pin (11-2) is connected with a connecting piece (12), the connecting piece (12) is connected with the N wiring strip (4) and the triac second electrode (10-2), the triac first electrode (10-1) is connected with the current transformer secondary coil first pin (11-3) and a reed (9), the reed (9) is connected with one side of a starting thermistor (8), the other side of the starting thermistor (8) is connected with a second pin (7), and the triac trigger electrode (10-3) is connected with the current transformer secondary coil second pin (11-4).

2. A zero-wattage motor start thermal protector according to claim 1, characterized in that: The blocking bar (5), the first pin (6), the second pin (7), the starting thermistor (8), the reed (9), the triac (10), the current transformer (11) and the connecting piece (12) are arranged in a cavity formed by the base (1) and a cover plate (13).

3. The zero-wattage motor start thermal protector of claim 1, wherein: The PE wiring strip (2), the L wiring strip (3) and the N wiring strip (4) are arranged in a peripheral cavity of the base (1).

4. The zero-wattage motor start thermal protector of claim 1, wherein: The N wiring strip (4) is provided with an N wiring strip plug end (4-1), an N wiring strip threaded end (4-2) and an N wiring strip connecting end (4-3), and the N wiring strip connecting end (4-3) is connected with the connecting piece (12).

5. The zero-wattage motor start thermal protector of claim 1, wherein: The first pin (6) is provided with a first pin insertion hole (6-1), a first pin connecting plug (6-2), a first pin connecting arm (6-3) and a first pin connecting slot (6-4), and the first pin connecting slot (6-4) is connected with the current transformer primary coil first pin (11-1).

6. The zero-wattage motor start thermal protector of claim 1, wherein: The second pin (7) is provided with a second pin insertion hole (7-1), a second pin connecting plug (7-2), a second pin connecting arm (7-3) and a second pin connecting end (7-4), and the second pin connecting end (7-4) is connected with the other side of the starting thermistor (8).

7. The zero-wattage motor start thermal protector of claim 1, wherein: The reed (9) is provided with a reed connecting No.1 slot (9-1), a reed connecting No.2 slot (9-2) and a reed spring piece (9-3), the reed connecting No.1 slot (9-1) is connected with the triac first electrode (10-1), the reed connecting No.2 slot (9-2) is connected with the current transformer secondary coil first pin (11-3), and the reed spring piece (9-3) is connected with one side of the starting thermistor (8).

8. The zero-wattage motor start thermal protector of claim 1, wherein: The connecting piece (12) is provided with a connecting piece connecting end (12-1), a connecting piece connecting arm (12-2), a connecting piece No. 1 connecting clamping groove (12-3), a connecting piece No. 2 connecting clamping groove (12-4), the connecting piece connecting end (12-1) is connected with the N wiring row (4), the connecting piece No. 1 connecting clamping groove (12-3) is connected with the current transformer primary coil second pin (11-2), and the connecting piece No. 2 connecting clamping groove (12-4) is connected with the bidirectional thyristor second electrode (10-2).

9. The zero-wattage motor start thermal protector of claim 1, wherein: The base (1) is provided with a PE wiring row mounting cavity (1-1), an L wiring row mounting cavity (1-2), an N wiring row mounting cavity (1-3), a first pin mounting cavity (1-4), a second pin mounting cavity (1-5), a connecting piece mounting cavity (1-6), a blocking strip mounting cavity (1-7), a starting thermal resistor mounting cavity (1-8), a reed mounting cavity (1-9), a bidirectional thyristor mounting cavity (1-10), a current transformer mounting cavity (1-11), a base No. 1 clamping hole (1-12), a base No. 2 clamping hole (1-13), a thermal protector mounting cavity (1-14) and a thermal protector mounting clamping hook (1-15).

10. The zero-wattage motor start thermal protector according to claim 1, wherein: The cover plate (13) is provided with a cover plate M jack (13-1), a cover plate S jack (13-2), a cover plate No. 1 clamping hook (13-3), a cover plate No. 2 clamping hook (13-4), a first pin jack positioning cavity (13-5), a second pin jack positioning cavity (13-6), a blocking strip limiting boss (13-7), a starting thermal resistor limiting boss (13-8), a reed limiting boss (13-9), a current transformer limiting boss (13-10) and a connecting piece limiting table (13-11).

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