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Home ProductsThermal Cutoff Switch

250V 5A 10A Thermal Control Switch For Power Supply

250V 5A 10A Thermal Control Switch For Power Supply

250V 5A 10A Thermal Control Switch For Power Supply
250V 5A 10A Thermal Control Switch For Power Supply 250V 5A 10A Thermal Control Switch For Power Supply 250V 5A 10A Thermal Control Switch For Power Supply 250V 5A 10A Thermal Control Switch For Power Supply

Large Image :  250V 5A 10A Thermal Control Switch For Power Supply Get Best Price

Product Details:
Place of Origin: CHINA
Brand Name: Yusheng
Certification: CQC,TUV,UL
Model Number: H21
Payment & Shipping Terms:
Minimum Order Quantity: 1000PCS
Price: Negotiable
Packaging Details: 4000pcs per Carton, Carton Size:280*260*320mm
Delivery Time: 5-7 working days
Payment Terms: T/T, Western Union
Supply Ability: 2,000,000PCS per Month
Detailed Product Description
Name: Thermal Cutoff Switch Model: H21
Contact Type: Normally Closed Or Normally Open Temperature Range: 40-150℃
Case: Metal Rated Volts & Amps: 250V AC 5A, 10A
Certificate: CQC, UL ,TUV Lead Wire: UL3135 AWG18, AWG20, AWG22, Or Customized
Lead Wire Length: L1=L2=70mm(standard), Can Be Customized Life Cycle: 10,000 Cycles
High Light:

10A Thermal Control Switch


H21 Thermal Control Switch


250V Thermal Cutoff Switch

250V 5A-10A 50-150 C Thermal Control Switch For Power Supply And Laminator


Quick Detail:

Model H21
Reset Type Auto Reset
  Single Pole,Single Throw(SPST)
Case Material: Metal
Rated Voltage & Current 250V AC 5A/10A
Contact Type Normally Closed(Open on Rise) or Normally Open(Close on Rise)
Operating Temperature Range 45~150℃
Temperature tolerance ±5.0℃
Contact Resistance ≤50mΩ
Insulation Resistance ≥100MΩ
Dielectric Strength ≥1500V
Life Cycle 10,000 Cycles

 1. H21 series Cut Off Switch’s Principle and structure

H21 serial universal and enhanced protectors with large metal casing are composed of the thermal conductive metal casing, bimetallic parts welded with silver alloy contact point, conductive bracket, insulation fixation stand, fixed contact strip and heat resistance cable. In case of abnormal operation, along with the increase of the environment temperature to the set value, the bimetallic parts perform quick action, open the contact point, and disconnect the circuit. When the device is cooled to the temperature for safe operation, the contact point will automatically closes and recover normal operation.



H20 thermal cutoff switch uses high sensitive disk-shaped bimetal strip as the temperature-sensing element. It is composed of bimetal strip, moveable contact, stationary contact piece, fixed base, moveable spring piece, case and temperature resistance lead wire.The bimetal strip is fixed on the base, which can maintain the consistency of disconnection and reset temperature after long-term use. Its' main function is overheating, overload protection.

Working principle: when the temperature rises to a certain value, the bimetal strip will instantly jump off and the contact will move quickly to disconnect the circuit. When the temperature falls to a certain value, the bimetal strip will be reset and the contact will return to the original state to achieve the purpose of switching the circuit. Its light weight, compact design maintains the lightweight, sealed housing of the whole device, and is resistant to drying, maintaining the accuracy and high reliability of disconnection and reset throughout its life.


Product features: H20 theraml overload prtoector is a temperature control switch developed by imported thermal bimetal, with small size, rapid action, accurate temperature control and long life cycle.


2. H21 series Cut Off Switch’s Specification


2.1.Switch type: normally closed, normally opened.

2.2.Operating Voltage / Current: AC250V / 5A; AC125V / 8A

2.3.Operating Temperature: 40~150 (one step for every 5°C)

2.4.Standard Tolerance: +-3°C / +-5°C / +-7°C

2.5.Reset temperature: operating temperature decrease by 15-45°C

2.6.Contact Closure resistance: ≤50mΩ

2.7.Insulation resistance: ≥100mΩ

2.8.Electric strength: AC1500V/1min free from phenomena of break down and flashover.

2.9.Service life: 10000 times


3. H21 series Cut Off Switch’s s Dimension 


250V 5A 10A Thermal Control Switch For Power Supply 0

250V 5A 10A Thermal Control Switch For Power Supply 1


2. Structural Drawing

250V 5A 10A Thermal Control Switch For Power Supply 2


No. Part Name Material Qty
1 Lead wire 0.75mm² black silicon wire 2
2 Sealing Epoxy resin A few
3 Insulation blcok Ceramic 1
4 Moveable contact AgNi10/Cu 1
5 Moveable spring piece Beryllium bronze 1
6 Case Plastic 1
7 Stationary Contact piece AgNi10/Cu 1
8 Base Brass H62 1
9 Bimetal strip BR-1 1


250V 5A 10A Thermal Control Switch For Power Supply 3

250V 5A 10A Thermal Control Switch For Power Supply 4

3. Action Temperature Table

H20 & H21 Series
Action Temperature Reset Temperature Action Temperature Reset Temperature
40±5℃ ≥27℃ 110±5℃ 73±15℃
45±5℃ ≥27℃ 110±5℃ 73±15℃
50±5℃ ≥30℃ 115±5℃ 76±15℃
55±5℃ ≥30℃ 120±5℃ 80±15℃
60±5℃ 40±15℃ 125±5℃ 83±15℃
65±5℃ 43±15℃ 130±5℃ 86±15℃
70±5℃ 46±15℃ 135±5℃ 90±15℃
75±5℃ 50±15℃ 140±5℃ 93±15℃
80±5℃ 53±15℃ 145±5℃ 96±15℃
85±5℃ 56±15℃ 150±5℃ 100±15℃
90±5℃ 60±15℃    
95±5℃ 63±15℃    
100±5℃ 67±15℃    
105±5℃ 70±15℃    
Remark :
Reset Temperature: 2/3 of Action Temperature, tolerance is±15℃ or customized.



1. Electric motors

2. Induction cooker

2. Warm handbag

3. Vacuum cleaner

4. Soybean milk machine

5. Ballast

6. Washing machine motor

7. Air conditioner fan motor

8. Transformer, ballast

9. Induction cooker

10. Electric heating belt

11. Health care equipment

12. Pump fan

13. Battery

14. Power tools

15. Heating pad


Competitive Advantages:

1. Fast temperature sensing

2. Accurate temperature control

3. Large control current

4. Low contact resistance

5. Safe and reliable

6. Small size, easy to install

7. No arc discharge

8. Long life cylces more than 10,000 times

9.  Anti-vacuum dipping process, can be dipped with the motor

10. There are two types of normally closed and normally open can meet customers' different requirements

11. The length and specifications of lead wire can be customized

12. Substitute SENSATA 7AM,17AM,SEKI St22 series

250V 5A 10A Thermal Control Switch For Power Supply 5


1. To avoid affecting the performance of the product, please do not collapse or deform the plastic or metal case when install H20 and H21 thermal overload protector.

2. To avoid leakage of electricity, please do not remove the insulation tube when install H21 thermal overload protector.

Thermostat Cut Off Switch, Thermal Control Switch, Temperature Cut Out Switch, Bimetal Temperature Switch

Contact Details
Dongguan Yusheng Electronics Co., Ltd.

Contact Person: Ms. Amy Li

Tel: 86-13553890655

Fax: 86-769-82869802

Send your inquiry directly to us