Transformer Overcurrent Protection PTC Thermistor

PTC thermistor for overcurrent overvoltage protection of transformer MZ31 series 

Brief Introduction:
MZ 31 series of PTC thermistor is a million- time safety device of automatic protection,recoverability, using repeatedly, and no trigger, noise or protective components that could protect and restore from abnormal temperature and current automatically,which called "auto restore fuse" and "ten-thousand-time fuse".Recoverability, using repeatedly, and no trigger, noise or sparks.  It can replace traditional fuse and widely applied in overcurrent and overload protection of motor, transformer, electronic circuit. PTC thermistor decreases its residual current through sharp resistance increasing, restraining consumption of the whole line,and it can restore its protective function after the trouble was removed.But traditional fuse could not restore after fusing in the circuit.

Applications:
Primary overcurrent,overload and overvoltage protection of transformers,adapters

Advantages:
1.Automatic protection,can resume steadily after protection
2.Contactless,noiseless and flameless;
3.Has complete specification
4.Reacts fast
5.Long stability
6.With a better performance of withstanding voltage,
   suitable for operating in 250/265V AC (high resistance state) continuously
7.small steady resistance;
8.low rated current.

Choose guidelines of PTC thermistor for protection of overcurrent and overload:
In selecting PTC thermistor as overload protection component,firstly,make sure of the maximum operating current in the circuit(non-trip current of PTC thermal resistor) and maximum operating voltage,rated zero power

resistance,and also the outlook and dimension should be also taken into consideration.
Relation between operating temperature,operating current and non-operating current is as shown in Fig 3 as below.Operating current is normally 2-3 times compared as non-operating current,and both of the currents

will be reduced as operating temperature increases.

Many specifications for choice,and samples&orders can be custom made per customers' requirement.