Start control circuit suitable for high-temperature dilution fan
By introducing a dual-output contactor and a time-delay relay into the starting control circuit of the high-temperature dilution fan, the problem of frequent operation of the thermal relay caused by large starting current is solved, and normal starting and overload protection of the motor are achieved.
Patent Information
- Application Number
- CN202422016647.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-08-20
AI Technical Summary
The high-temperature dilution fan has a large starting current, which causes the thermal relay to operate frequently during startup, making it unable to start normally or unable to provide effective overload protection during operation.
A combined control circuit of dual-output contactors and time-delay relays is used to delay the start of the dual-output contactors through the time-delay relay to avoid large currents during startup, ensure normal startup of the motor, and provide overload protection during operation.
The normal startup and overload protection of the high-temperature dilution fan during operation are realized, tripping phenomenon during startup is avoided, and the safe and reliable operation of the motor is ensured.
Smart Images
Figure CN223451851U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of starting control circuit suitable for high-temperature dilution fan. BACKGROUND
[0002] Thermal relay is generally used as the overload protection of motor, and for general motors, the overload protection can be realized by setting thermal relay, but for high-temperature dilution fan, some problems may occur when using thermal relay to protect the motor from overload. Compared with ordinary fan, high-temperature dilution fan has long starting time and large starting current. For example, a high-temperature dilution fan with power of 11 kW and rated current of 20.3 A, the setting range of thermal relay should include the rated current value. In actual application, due to the excessive starting current, heat accumulates rapidly, and the thermal relay acts before reaching the trip time of the characteristic curve, so that the motor cannot start normally. If a thermal relay with higher protection range is selected, the thermal relay will not act when the motor starts normally and overloads occur. During the starting process of the motor, the thermal relay will trip. However, selecting a larger thermal relay cannot avoid the tripping result, and even if the motor starts successfully, the thermal relay cannot protect the motor from overload during normal operation. SUMMARY
[0003] The utility model discloses a kind of starting control circuit suitable for high-temperature dilution fan, to ensure that the motor starts normally and thermal relay plays a role in overload protection during operation.
[0004] To achieve the above object, the utility model provides the following scheme:
[0005] A starting control circuit suitable for a high-temperature dilution fan, comprising a motor starting main circuit and a start-stop control circuit, the motor starting main circuit comprising a main control contactor and a thermal relay, the power output of the main control contactor being connected to the fan via the thermal relay, the start-stop control circuit comprising a control circuit of the main control contactor, wherein: in the main circuit, a dual-output contactor is provided between the main control contactor and the thermal relay, the normally open main contact of the dual-output contactor being the first output, the normally closed main contact of the dual-output contactor being the second output, the power output of the main control contactor being connected to the input end of the thermal relay via the first output of the dual-output contactor, the power output of the main control contactor being connected to the thermal relay via the second output of the dual-output contactor The output end of the relay and the fan; a delay relay is provided in the start-stop control circuit, and the delay switch of the delay relay is connected between the control power supply of the start-stop control circuit and the starting coil of the dual-way output contactor. The starting coil of the main control contactor is connected in parallel with the delay relay. When the main control contactor is started, the delay relay is energized at the same time. After energization, the delay switch of the delayed closure of the delay relay powers the starting coil of the dual-way output contactor, thereby forming a main control contactor that first directly starts the fan through the normally closed main contact of the dual-way output contactor after power is applied, and then delays the starting of the dual-way output contactor through the delay switch. The power output of the main control contactor is then connected to the fan through the normally open main contact closed by the dual-way output contactor through the thermal relay.
[0006] The solution is further that: the first output and the second output of the dual-output contactor are locked to each other.
[0007] The solution is further as follows: the delay time of the delay relay is set to at least 10 seconds, and after the delay relay is powered on, the delay switch is closed after a delay of 10 seconds to start the dual-channel output contactor.
[0008] The beneficial effects of the utility model are as follows: the control circuit is simple, and a time delay relay is added to the control circuit. During the startup process, the fan is first directly started via the normally closed main contacts of the dual-way output contactor, and then the startup of the dual-way output contactor is delayed by the time delay relay, thereby avoiding the large current during the startup of the fan and avoiding the tripping phenomenon of the overload protection during the startup of the motor. The utility model can normally start and operate a high-temperature dilution fan with a large starting current and a long starting time through the use of the dual-way output contactor and the time delay relay.
[0009] The utility model is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a schematic diagram of the circuit structure of the utility model. DETAILED DESCRIPTION
[0011] A start-up control circuit suitable for high-temperature dilution fans, such asFigure 1The starting control circuit includes a motor starting main circuit 1 and a start-stop control circuit 2. The motor starting main circuit 1 includes a master contactor 101 and a thermal relay 103. The power output of the master contactor 101 is connected to a fan 104 (M) through the thermal relay 103. The start-stop control circuit has a control circuit of the master contactor. In the starting main circuit 1, a two-way output contactor 102 is arranged between the master contactor 101 and the thermal relay 103. The normally open main contact KM2-1 of the two-way output contactor 102 is the first way output of the two-way output. The normally closed main contact KM2-2 of the two-way output contactor 102 is the second way output of the two-way output. The normally open main contact KM2-1 and the normally closed main contact KM2-2, i.e. the first way output and the second way output, are mutually interlocked in two options. The power output of the master contactor 101 is connected to the input end of the thermal relay 103 (FR) through the first way output of the two-way output contactor 102. The power output of the master contactor 101 is connected to the output end of the thermal relay 103 and the fan 104 (M) through the second way output of the two-way output contactor 102. In the start-stop control circuit 2, a delay relay KT is arranged in the control circuit of the master contactor 101. The delay switch KT-1 of the delay relay KT is connected between the control power 220V of the start-stop control circuit 2 and the starting coil KM2 of the two-way output contactor 102. The starting coil KM1 of the master contactor 101 is connected in parallel with the delay relay KT. When the master contactor 101 is started, the delay relay KT is energized at the same time. The delay switch KT-1 is delayed to close and supply power to the starting coil KM2 of the two-way output contactor 102 through the delay of the energized delay relay KT, thereby forming the master contactor 101. After power-on, the fan 104 is first started directly through the normally closed main contact KM2-2 of the two-way output contactor 102, and then the two-way output contactor 102 is started through the delay switch KT-1. The power output of the master contactor 101 is connected to the fan 104 through the normally open main contact KM2-1 of the two-way output contactor 102 and the thermal relay 103, and the normally closed main contact KM2-2 of the two-way output contactor 102 is opened.Wherein: in the main circuit, the power supply 220 / 380V is connected to the input of the main control contactor 101 through the switch QF; in the start-stop control circuit 2, the power supply 220V provides the control power supply of the start-stop control circuit 2 through the fuse FA, the 220V control power supply provides power supply for the start coil KM1 of the main control contactor 101 and the delay relay KT through the stop button SS1 and the start button SF1 in series; the auxiliary normally open contact KM1-2 of the main control contactor 101 is connected in parallel with the start button SF1 for keeping power-on after the main control contactor 101 is started; the 220V control power supply is connected to the start coil KM2 of the double-way output contactor 102 through the delay switch KT-1 of the delay relay KT; the auxiliary normally closed contact KM1-3 of the main control contactor 101 connects a power-on indicator light PWG with the power-on power supply 220V of the start-stop control circuit 2 for indicating the power-on of the start-stop control circuit; meanwhile, a start indicator light PGG is connected in parallel with the start coil KM1 of the main control contactor 101 and the delay relay KT for indicating that the fan 104 (M) has been started.
[0012] In the embodiment, the delay time of the delay relay is set to at least 10 seconds, and the delay switch of the delay relay is closed to start the double-way output contactor after 10 seconds of delay after the delay relay is powered on.
[0013] The above-mentioned start control circuit embodiment suitable for high-temperature dilution fans has simple control circuit, by adding a delay relay in the control circuit, the fan is first started directly through the normally closed main contact of the double-way output contactor, and then started through the delay relay of the double-way output contactor, which avoids the large current during the start of the fan and avoids the tripping phenomenon of the overload protection during the start of the motor.
Claims
1. A starting control circuit for a high-temperature dilution blower, comprising a motor starting main circuit and a start-stop control circuit, wherein the motor starting main circuit comprises a main control contactor and a thermal relay, the power output of the main control contactor is connected to the blower via the thermal relay, and the start-stop control circuit comprises a control circuit of the main control contactor, characterized in that: In the main circuit, a dual-output contactor is provided between the main control contactor and the thermal relay. The normally open main contact of the dual-output contactor is the first output, and the normally closed main contact of the dual-output contactor is the second output. The power output of the main control contactor is connected to the input end of the thermal relay via the first output of the dual-output contactor, and the power output of the main control contactor is connected to the output end of the thermal relay and the fan via the second output of the dual-output contactor; a delay relay is provided in the start-stop control circuit, and the delay switch of the delay relay is connected to the start-stop control circuit. Between the control power supply of the control circuit and the starting coil of the dual-channel output contactor, the starting coil of the main control contactor is connected in parallel with the delay relay. When the main control contactor is started, the delay relay is energized at the same time. After energization, the delay switch of the delayed closure of the delay relay energizes the starting coil of the dual-channel output contactor, thereby forming a main control contactor that first directly starts the fan through the normally closed main contacts of the dual-channel output contactor after power is applied, and then delays the start of the dual-channel output contactor through the delay switch. The power output of the main control contactor is then connected to the fan through the normally open main contacts closed by the dual-channel output contactor through the thermal relay.
2. The startup control circuit for a high-temperature dilution blower according to claim 1, characterized in that: The first output and the second output of the dual-output contactor are locked to each other.
3. The startup control circuit for a high-temperature dilution blower according to claim 1, characterized in that: The delay time of the delay relay is set to at least 10 seconds. After the delay relay is powered on, the delay switch is closed after a delay of 10 seconds to start the dual-channel output contactor.