thermal protector for transformer
BW series thermal protector’s Principle and structure
BW series thermal protector is to use a certain geometry of
bimetallic strip, without auxiliary institutions, only by
bimetallic strip their own sense of mild heating current, rapid
changes in the state of bimetallic element, direct drive contact
automatic cutting and processing circuit, overheat protection,
overload protection.
BW series thermal protector’s application
It is widely applied in Electric motors and electrical equipment as
electric blanket, hot wall, washer motor, soybean milk machine
motor, Fan motor, air condition motor, fractional motor, direct
current motor, AC brushless motor, water pump, transformer,
rectifier, lighting, rechargeable battery,electric heating
appliance etc.
BW series thermal protector's specification
1. Contact’s type: Normally closed and Normally open
2. Electrical rating: 10A/AC120V; 8A/AC250V; 10A/AC250V; 16A/AC250V
3. Circuit resistance: ≤50mΩ (Initial value)
4. Insulation resistance: ≥100mΩ
5. Action temperature range: 40~150℃
6. Case: metal case and plastic case
7. Life: ≥10,000 times
8. Size:
| Model | L(mm) | W(mm) | H(mm) | Electrical rating | Lead wire (mm) |
| BW metal | 20 | 7.5 | 3.8 | 5A/250V;10A/250V | AWG#22,AWG#18 high temperature silicone wire L1=L2=70mm, or
according to customer’s requirement. |
| 20 | 8.0 | 4.1 | 16A/250V |
| BW plastic | 20 | 8.0 | 4.0 | 5A/250V;10A/250V |
9. Open temperature and reset temperature sheet
| Code | Open temp. | Reset temp. | Code | Open temp. | Reset temp. |
| 40 | 40℃±5℃ | ≥30℃ | 100 | 100℃±5℃ | 70±10℃ |
| 45 | 45℃±5℃ | ≥30℃ | 105 | 105℃±5℃ | 70±12℃ |
| 50 | 50℃±5℃ | ≥30℃ | 110 | 110℃±5℃ | 75±12℃ |
| 55 | 55℃±5℃ | ≥30℃ | 115 | 115℃±5℃ | 80±12℃ |
| 60 | 60℃±5℃ | 40±10℃ | 120 | 120℃±5℃ | 85±12℃ |
| 65 | 65℃±5℃ | 45±10℃ | 125 | 125℃±5℃ | 90±12℃ |
| 70 | 70℃±5℃ | 50±10℃ | 130 | 130℃±5℃ | 95±12℃ |
| 75 | 75℃±5℃ | 55±10℃ | 135 | 135℃±5℃ | 100±12℃ |
| 80 | 80℃±5℃ | 60±10℃ | 140 | 140℃±5℃ | 105±12℃ |
| 85 | 85℃±5℃ | 65±10℃ | 145 | 145℃±5℃ | 110±12℃ |
| 90 | 90℃±5℃ | 70±10℃ | 150 | 150℃±5℃ | 115±12℃ |
| 95 | 95℃±5℃ | 75±10℃ | | | |
BW Thermal protector’s competitive advantage
1. Small size and easy installation
2. Quick bimetallic strip, fast reaction
3. The life time high than 10,000 times
4. Prevention again leak of vacuum impregnation process
5. Replacer of SENSATA 17AM 7AM, SEKI ST-22 etc.
BW series’drawing
