China custom bimetallic thermal disc cutoff switch has surface mount and PCB plug-in installation. Overheat circuit cutoffs switch (bimetal thermostat) are devices designed to keep components safe in situations when an excessive temperature occurs. List of Select Surface Mount Thermal Switches and thermal protectors product Specs, datasheets, manufacturers & suppliers.
Surface Mount Bimetal disc Thermal Switch are indispensable components in the safe and efficient operation of motors/ Electrical appliances. By preventing overheating, they protect Electrical appliancesfrom damage, extend their operational life, reduce the risk of fire hazards, ensure safe operation, and minimize downtime and maintenance costs. Furthermore, Bimetal disc thermal switch help in complying with industry safety standards, providing peace of mind to operators and stakeholders. As technology advances, thermal switch continue to evolve, offering more precise and reliable protection for motors in a wide range of applications.
With the development of technology, the application range of motor is more and more extensive, especially the use of motor in daily life and production is also more and more important. But the motor burn accident also happens, in real life, the motor burn is mainly caused by the following blocked coil overheating, the load is too large motor overload, lack of phase and other reasons. Installing a heat protector is one of the effective ways to protect the motor. toplotno stikalo, also called temperature switch, temperature control switch, itd. It is a kind of temperature switch with bimetal sheet as a temperature sensing element, when the electrical appliance is working normally, the bimetal sheet is in a free state, the contact is in a disconnected state, when the temperature rises to the action temperature value, the bimetal element is heated to produce internal stress and rapid action, open the contact, cut off/connect the circuit, so as to play a bimetal thermal switch role. Wait until the ambient temperature drops to thereset temperature of the protector, the contact will re-close the connected circuit, and the motor will work again.
Choosing The Right thermal switch
How to choose the right circuit Off bimetal disc switch is very important, otherwise not only cannot play a protective role, but will cause the motor cannot work because of the wrong selection, or even burn.
1. Voltage & Current determination
• Bimetal disc thermal switch have different voltage ranges 400V 380V 230V 220V 110V, DC motors will also have 36V 24V 12V, itd., according to different working voltages to choose different rated voltage protectors, in principle, the actual application voltage is less than or equal to the rated voltage of the protector, for example, 380V motor cannot choose rated voltage 220V protector, and rated voltage 220V protector can be used in 110V motor;
• The current of the electrical appliances motors is divided into three kinds of starting current, normal working current and blocked current, the rated current of the protector should be greater than the maximum value of the three currents, and need to leave a margin. For example, a motor normal working current 1A, starting current 1.5A, blocking current 2A, then the rated current of the selected protector is at least 2A, and it is best to choose the rated current of 3A or 5A to retain the margin. Some motor starting current is greater than the rated current of the protector, but the starting time is shorter, and the normal working current and blocking current are less than the rated current of the protector, in this case, you can also choose this protector. Because the starting current is greater than the rated current, but due to the short time, the thermal effect of the current has not had time to make the double piece heat leading to protection of the protector, so as not to cause misaction.
2. Choose to thermal switch the temperature
• The choice of thermal switch temperature is related to three factors: insulation level of enameled wire, installation position and protector type.
The thermal switch temperature is lower than the maximum allowable temperature, for example, the maximum temperature ofF class is 155℃, and the actual selection can be 145℃ or 150℃.
•The installation position is divided into built-in inside the coil and bundled outside the coil, because when the motor is blocked and forwarded heat, the overheating phenomenon spreads from inside and outside. If the protector is buried in the interior, the thermal switch temperature is slightly lower than the highest temperature of the enamelled wire; If it is tied outside the coil, consider the temperature difference between the inside and outside, and choose a lower temperature protector. For example, the insulation level is F class enameled wire, coil inside and outside the temperature difference of 20℃, then choose 155-20=135℃ or so of the protector;
Motor protector has protection functions such as overload, phase failure, imbalance, underload, grounding/leakage, and stall. It can form a motor control protection unit with electrical components such as contactors and motor starters. It has functions such as remote automatic control, on-site direct control, panel indication, signal alarm, and field bus communication.
3. Selection of the thermal switch life
Different motor lock-in test time different requirements for the life of the protector are not the same, such as normal household motor lock-in 18 days, the number of cycles of normal action reset will not exceed 100000 times, the rated voltage current life of more than 100000 times can be selected protector; Some pump motors only do 3 days of blocking, in principle, the life requirement is hundreds of times.
4. Selection of the thermal switch for sealing performance
Motor coil in the thermal switch process will dip paint to enhance the insulation performance of the process, dip paint is divided into drop paint, immersion, vacuum into the paint and other processes, especially the vacuum into the paint pressure is large, insulating paint is easy to enter the inside of the protector, resulting in the failure of the protector. The ST01 series of An Electronics has a very high sealing, under the condition of -0.08MP, the paint dipping rate can reach 3%; In the case of -0.03MP, the paint rate can reach less than one in ten thousand.
Motor protector parameters
Technical parameters
Auxiliary power supply |
Technical indicators | |||
ARD2(L) | ARD2F | ARD3 | ||
Auxiliary power supply | Voltage | AC85V~265V/DC100V~350V | ||
Voltage | ≤7VA | ≤15VA | ||
Rated working voltage | AC380V/AC660V,50Hz/60Hz | |||
Rated operating current | 1A(0.1~9999) | |||
5A(0.1~9999) | ||||
1.6A(0.4A~1.6A) | ||||
6.3A(1.6A~6.3A) | ||||
25A(6.3A~25A) | ||||
100A(25A~100A) | ||||
250A(63A~250A) | ||||
800A(250A~800A) | ||||
Relay output contact capacity | AC250V/ 3A;DC30V/ 3A | AC250V/ 6A | ||
Switch input | 2-way | 9-way | ||
Environment | Working temperature: -10°C~55°C | |||
Storage temperature: -20°C~65°C | ||||
Relative humidity: 5﹪~95﹪ without condensation | ||||
Altitude: ≤ 2000m | ||||
Pollution level | 2 | |||
Protection level | IP20 | Main unit IP20 Display unit IP45 | ||
Installation category | Level III |
Bimetal motor protector
Technical parameters | Technical indicators | ||
ARD3T auxiliary power supply | AC/DC 110 / 220V or AC 380V,power consumption≤15VA | ||
Motor rated working voltage | AC 380V / 660V,50Hz / 60Hz | ||
Motor rated working current | 1.6(0.40A-2.00A) | Measured using measurement module | |
6.3(1.6A-6.3A) | |||
25(6.3A-25A) | |||
100(25A-100A) | |||
250(63A-250A) | Using external current transformer + measurement module | ||
800(250A-800A) | |||
Leakage current | 50mA-1A | Using measurement module + leakage current transformer | |
3A-30A | |||
Relay output contact capacity | Resistive load | AC250V、6A;DC24V、6A | |
Inductive load | AC250V、2A;DC24V、2A | ||
Main switch input and output | 4DI、4DO,DI Can be dry or wet node | ||
Switch module | 4DI、3DO,DI Can be dry or wet node | ||
Temperature module | External sensor type:PT100、PT1000、Cu50、PTC、NTC
Number of sensor channels: 3 Corresponding measurement range of sensor: PT100/PT1000:-50°C~+500°C Cu50:-50°C~+150°C PTC/NTC:100Ω~30kΩ |
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Analog module | Can be realized: 2-way 4~20mA input measurement, 2-way 4~20mA transmission output
4~20mA input measurement accuracy ±0.5% 4~20mA output maximum load capacity is ≤500Ω |
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Main communication | RS485:Modbus-RTU | ||
Communication module | RS485:Dual Modbus-RTU、Profibus | ||
Environment | Working temperature | -10ºC~55ºC | |
Storage temperature | -25ºC~65ºC | ||
Relative humidity | ≤95﹪No condensation, no corrosive gas | ||
Altitude | ≤2000m | ||
Pollution level | Level 3 | ||
Protection level | Main body IP20, split display module IP45 (installed on the cabinet) | ||
Installation category | Level III | ||