MZ32 Inrush Current Suppression Series (PTC Thermistor)
Product Overview
The MZ32 series is a positive temperature coefficient (PTC) thermistor inrush current suppressor. It is specially designed for surge peak current at the moment of power-on in high-power circuits, protecting rectifier bridges, power semiconductors, filter capacitors and fuses from overcurrent impact. It features dual functions of current limiting + self-recovery.
Working Principle
It maintains low resistance at room temperature, which can slowly charge large-capacity capacitors and suppress inrush current during power-on;
As the current rises, the component heats up and its resistance increases sharply, entering a high-resistance current-limiting state;
After the surge disappears or power is cut off, the temperature drops and the resistance automatically returns to a low value for repeated use, with the characteristics of a self-recovering fuse.
Product Features
✅ High-power suppression: Specially applied to suppress power-on inrush current of AC-DC power supplies, inverters, transformers and motor inductive loads;
✅ High voltage resistance: AC 120V～500V, covering mainstream voltage for industrial and consumer electronics;
✅ Wide resistance range: 10Ω～1000Ω, available for selection according to load matching;
✅ Stable and reliable: Ceramic substrate with flame-retardant packaging, low drift during long-term operation;
✅ Self-recovery: No replacement required, automatic reset after fault elimination, low maintenance cost;
✅ Multiple structures optional: A chip type, B housing type and C coating type, adapting to different installation spaces.
Typical Applications
High-power switching power supplies, industrial inverters, UPS;
Compressor and motor start-up for home appliances (air conditioners, refrigerators, washing machines);
New energy equipment and charging pile power modules;
Magnetizing inrush current suppression for inductive loads such as transformers and reactors;
Medical and communication power supplies, as well as various large-capacity capacitor input circuits.
Typical Core Parameters
Withstand Voltage: AC 220V / 380V / 500V (optional)
Resistance: 20Ω / 50Ω / 100Ω (@25℃)
Steady-state Current: 3A～15A (depending on model)
Curie Temperature: Approx. 125℃
Package: Insulated housing / epoxy coating, UL94 V-0 flame retardant grade
Selection Guidelines
The higher the power supply power and capacitor capacity, the smaller the resistance and the larger the steady-state current specification shall be selected;
Common model for 220VAC, 1–2kW power supply: MZ32-50Ω/8A;
Common model for 380VAC, 3–5kW power supply: MZ32-100Ω/10A.
