Yes, our factory is in Ynagzhou Jiangsu, near Shanghai. And we also have office in Guangzhou Guangdong.

All clients are welcome to visit our factory.

We can provide 5-10 pcs thermal protector samples for free, but the overseas shipping cost will in your side.

Pls let us know your specific contact information and specificateion, if you want to have free samples from us.

The warranty period of thermal protector we promised is not a specific time, like how many days, months or years, but the action cycles of thermal protector. Normally the life cycles ranges from 3,000 to 10,000 cycles according to different models and working capacity. It is one of the most important parameters of thermal protectors. Customers can find it in the specification of different models.

The life cycles we mentioned here are only for working under rated current and voltage. If the working condition changed, the final life endurance would be also different.

Our acceptable payment terms of thermal switch are as below:

1. 100% T/T before production (It is suitable for total amount less than USD5,000)

2. 50% T/T deposit, balanced payment before shipment.

3. For the sample fee, if the customer can pay the delivery cost, we will provide 5-10pcs samples for free. If the customer can not pay the delivery cost, it will be charged for both sample and delivery cost accrding to the International Express price we have.

4. 100% T/T before shipment. For big and reliable clients, we can accept NET 30days against invoice date.

Our common lead time for bimetal thermal switch is 15 to 35 days upon receipt of advance. If we have inventory, the lead time could be 7-10 days. For new products ,the lead time would be 25 to 40 days.

Sometimes rush orders are also acceptable, but the lead time should be agreed by both sides before order release.

Since all our bimetal thermal switches are with small size, the shipping term should be based on the order quantity. If the order is above 50,000 pcs per shipment, the most economical shipping term is by sea. If the order quantity of thermal switch is less than 10,000 pcs per shipment, shipping by express would be the only choice because the weight of 10,000 pcs would be less than 50Kg, MOQ of shipping by air. For the quantity between 10,000 and 50,000 pcs, express or shipping by air is optional, depending on the weight of different thermal switches.

1. To ensure the quality consistence of our bimetal thermal switch, we got ISO9001:2015 version certification and fulfill the system strictly.

2. The life endurance we guaranteed is based on the working enviroment and rating. Different thermal switch has different level, like 10,000 cycles, 30,000 cycles.

3. The defective rate of our thermal switch that we promise to our customer is 20 to 100 ppm according to different application.

We can guarantee that our price is competitive based on the same quality level. The quality of bimetal thermostat cannot be distinguished by the picture or appearance. To ensure the good quality consistence, we import the key raw materials like bimetal-disc, insulation paper and contacts from USA, Japan and Germany.

The appearances of all these materials look same, but the quality level and price are totally different. Therefore, we believe that good quality product should have reasonable price.

A: If you need to have temperature sensitive thermal protector samples, please prepare the following parameters:

1. Rated voltage, rated current.

2. Operating temperature and rest temperature of thermal protectors.

3. Length of lead wire, color, type and temperature resistance.

4. Application of thermal protector.

5. Mounting requirements if needed, including dimensional requirements. Our ST01 & ST06 can insert to the coils of electric motor or transformers.

B: If you want to have current sensitive thermal protector samples, you may prepare three more parameters besides the above:

1. Trip off current

2. Trip off time

3. Normally working temperature of thermal protector. It can not trip off under this temperature.

When you see the term “thermal protection” or “electric motor thermal protection” used in the description of an electric motor, it refers to a device found within the motor or motor compressor that is designed to prevent dangerous overheating that can cause motor failure.

The Purpose of a Thermal Protector

This overheating generally occurs when the motor is overloaded, when a bearing seizes up, when something locks the motor shaft and prevents it from turning, or when the motor simply fails to start properly. A failure to start may be caused by faulty start windings in the motor.

The thermal protector consists of one or more heat-sensing elements built into the motor or motor-compressor, plus an external control device for motor overheat protection. The thermal protection is present to turn the motor off when excessive heat is generated within the motor circuitry, halting the temperature climb before it can burn up the motor.

These thermal protectors reset themselves once the motor cools down to a safe operating temperature. There is usually a visible red button located on the wiring side of the motor— usually, though not always, located opposite of the motor shaft. On motors equipped this way, you must press the reset button to reset and restart the motor. On other motors without a reset button, the reset happens automatically as the motor cools.

Having a motor shut down because it tripped a thermal limit is inconvenient, but it certainly is better than having to replace a motor because it overheats. And the shut-down can alert you to problems with the motor or connected devices, or to the load attached to the motor. When a motor fails to start or overheats during operation, it may indicate that the motor has reached the end of its useful life and must be replaced. But often the fault does not lie with the motor at all. There could be an obstruction on the load attached to the motor, leading to excessive load that causes heat to build up in the motor—tripping the thermal protector that saves the motor.

  1. Logistics Service. We have contracts with TNT, FedEx,UPS and some forwarders, which can offer you door to door service. The cost based on freight prepaid is 30 percent to 50 percent lower than the cost based on freight collect. Most of the cargos are transferred from H.K . We do this is to cut down the cost of the shipment for our customers and make their goods more competitive in price.
  2. Providing all kinds of Accessories. Lead wire with additional length, connectors, terminals, brackets for easy mounting etc. are available for our thermal protectors. We have complete supply chain and even prepare stocks of many kinds of materials such as electric wire, silicone rubber wire, teflon wire, AMP & Molex teminals and connectors from Taiwan or Mainland, and so on. Customization is our strong point.
  3. Total solution of Overheat. We have good business relationship with near 30 manufacturers specializing in thermal protector, thermal cutoff, thermostat, resetable fuse, thermal sensor. Some of them authorize us as their sole agent in the world market, some of them OEM for us. Some of them are our distributors in domestic market. We can offer our customers total solution to over heat and purchase various kind of products for thermal control for our customers. Moreover, we offer inspection service to make sure the quality for the imports of our customers.

Testing be done in the oven that the precision of constant temp is ±1℃. When testing, the thermocouple or thermometer should be place nearest to samples. During temperature rising ,when the temperature reaches 10℃ less than rated temperature, the temperature rising rate should be less than 0.5℃per minute and the testing current should be no more than 0.01A.

  1. Due to plenty of types of thermal protector, it is much of headache to choose which thermal protector is suitable. Hereafter are the three forms for thermal protector selection of three main industries (battery pack, motor and ballast), what you only do is to fill the form and send it to sa8@saftty.com, we would contact you!Thermal protector for battery packInstallation:In recharging circuit □In discharging circuit□In both recharging and discharging □;Other installation________________Recharging current: ________ A;  Recharging time: _____minsDischarging current:________ A; Discharging time: _____minsMaximum current in abnormal situation: _____A; Abnormity time: _____minsTechnology requirements to protector:Opening temperature: _________ ℃;Opening precision: ________ ℃(normally ±5 ±8 ±10℃)Reset temperature:_________℃; Reset precision: ________ ℃(normally ±10~15℃)Resistance: < ______  mΩ;

    Lead wire:_______________

    Thermal protector for motors

    Rated voltage: ________ V ;Working current: ________ A;

    Insulated level: _________

    Starting current: ________A;    Starting time: ________A

    Ambient temperature:  ________℃;

    Current of overload:_________ A; Temperature rising rate: ________℃/mins;

    Installation and varnish way:

    Installation:built-in□ out-lay□;

    Varnish: drop varnish□   vacuum varnish process □(pressure_____MPa)

    no drop varnish □   Immersion varnish□

    Technology requirements to protector:

    Opening temperature:________ ℃;Opening precision: ______℃(normally ±5 ±8 ±10℃)

    Reset temperature:_________ ℃; Reset precision:  ________ ℃(normally ±10~15℃)

    Cycles: ________  ;

    Lead wire:__________

    Thermal protector for lighting, ballasts and transformers

    Rated voltage:_______ V ;Working current:  _______ A;cosФ:____     ;

    Starting current: _____A;   Maximum current of overload:________ A;

    Ambient temperature:  _______℃; Temperature rising rate: _________℃/mins.

    Installation and varnish way:

    Installation: Embeding into the coil □; Banding in the coil □;

    The surface of power tube □; Other places_____

    Varnish: drop varnish□   vacuum varnish process □(pressure       MPa)

    no drop varnish □   Immersion varnish□

    Technology requirements to protector:

    Opening temperature:________ ℃;Opening precision:  __________℃(normally ±5 ±8 ±10℃)

    Reset temperature:__________ ℃; Reset precision: _________ ℃(normally ±10~15℃)

    Cycles: ________ ;

    Lead wire:________________


Theory of Protection

The operating principle of the thermal protector is simple and effective. At the heart of the protector is a bimetal snap-action disc. When the temperature of this disc reaches its pre-calibrated temperature it snaps open, resulting in an open circuit. This temperature is reached during a fault condition, caused by either an increase in ambient temperature, an increase in current flowing through the disc, or a combination of both. After thermal protector breaks the circuit, the system cools and it automatically resets allowing power to be restored to the circuit.

Opening Temperature

The temperature at which thermal protector makes the circuit open.

Reset Temperature

The temperature at which thermal protector reset the circuit as it cools.

Maximum Contact Ratings

The cycles of thermal protector reverts the circuit from open to reset when it works

under rated current and voltage.

1. Customer Request

Our experienced employees receive your request from the website and get in touch with you to get further information in order to have a better understanding of your specific requirements.

2. Further Assessment of the Request

After getting comprehensive information from our customers’ needs, We analyze all those elements and situations carefully to find the best options and solutions.

3. Technical Preparation and Survey of Costs

We do the proper survey and ensure providing the most reasonable offer to you.

4. Product and process development including testing

To ensure our thermal protectors are in a good performance and best fit your applications, we conduct various tests to ensure qualified delivery.

5. Present prototype to customer

We deliver our standard samples within in day and customized samples within one week.

6. Approval for pilot production and order is created

Still cannot get the information you want? Simply leave your requirements and we will do the rest.



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