Product Description
Motor starting PTC thermistors are automatic starting components designed specifically for single-phase induction motors (such as compressors, refrigerators, and air conditioner motors). Single-phase induction motors cannot generate starting torque on their own and require an auxiliary winding (starting winding) to provide the initial rotating magnetic field. In this starting circuit, the PTC thermistor acts as an "intelligent switch," connecting the starting winding at the moment of startup and automatically disconnecting it once the motor reaches rated speed, ensuring reliable starting and efficient operation.
Specification
Product Name: Motor Sarting PTC Thermistor
R25 : 30-60Ω±25%
Diameter : 9mm
Non-action current : 83±7℃
Max voltage : 450V
Application : Single-phase induction motor
Color : Black
Features
Automatic Switching Function: At room temperature, the PTC exhibits a low resistance state. When energized, it allows high current to flow through the start winding, generating starting torque. Subsequently, the current flowing through it generates heat. When its temperature exceeds its Curie point, its resistance increases dramatically (a sudden change), virtually shutting off the current flowing through the start winding, effectively "closing" the circuit.
Contactless and Noiseless: As a solid-state electronic component, its operation process does not involve the closing and closing of mechanical contacts, thus avoiding the arcing and noise associated with traditional electromagnetic relays, resulting in quiet and reliable operation.
High Reliability and Long Life: With no moving mechanical parts, there is no risk of wear, adhesion, or erosion. Its lifespan far exceeds that of traditional mechanical starter relays, reaching over a million cycles.
High Safety: Its inherent self-healing property allows the motor to cool down after stopping, automatically returning to a low resistance state, ready for the next start. Furthermore, its high resistance effectively prevents the start winding from accidentally being connected while the motor is running, potentially burning it out.
Anti-voltage fluctuation: Its working state mainly depends on its own temperature, it is insensitive to fluctuations in power supply voltage, and its startup performance is relatively stable.
Application
This type of PTC thermistor is almost exclusively used in single-phase induction motors that require split-phase starting, particularly in:
Refrigeration compressors:
Household refrigerator/freezer compressors: This is the most classic and widespread application.
Room air conditioner (window unit, split unit outdoor unit) compressors.
Dehumidifier compressors.
Small water pumps: Certain high-power single-phase water pumps.
Power tools: Some large single-phase motor-driven equipment.
