PTC BASICS

FUNCTION AND OPERATING PRINCIPLE

PTC elements (chips) are ceramic resistors (temperature dependent resistor components).

 

They consist of doped, polycrystalline ceramic materials based on barium titanate.

 

PTC stands for Positive Temperature Coefficient.

 

As the temperature rises, the resistance increases, which in turn causes the electrical

conductance and consequently the performance to fall. If the temperature falls so does

the resistance while the electrical conductance and the performance increase.

 

The PTC heat register has a high level of operational safety

due to this integrated temperature limiting effect.

 

With an appropriate design layout, it is possible to self-regulate the register.

 

The performance is the pure electrical power output.

 

The Curie point temperature describes the point where the PTC thermistor characteristic

starts to rise steeply.

 

The maximum possible surface temperature can increase to approx. 5 % above the

Curie temperature (with insufficient air volume flow).

REGISTER STRUCTURE

We use only registers with PTC chips bonded with aluminum heat segments

that conduct electricity. The chips are sealed after bonding for optimal protection against

dirt and moisture.

 

Compared to electrically insulated registers they have a higher power density

with reduced dimensions.

 

In comparison to mechanically preloaded chips (without bonding) their activation current

increase is flatter and consequently gentler on materials.

INTEGRATED OVERHEATING PROTECTION

Unlike conventional wire or tubular radiators, which can reach over 1,000 °C with insufficient

air flow, this is not possible with PTC elements; they have an integrated temperature limit.

 

According to VDE regulations, two independent temperature limiters should be used for

electrical heating elements, the same as are used for conventional wire or tubular radiators.

 

PTC elements require only one other external temperature safeguard

due to their internal temperature limit.

SELF REGULATING FEATURE

PTC registers have self-regulating features and can be dimensioned in a way

that they can guarantee proper regulating behavior in line with the air volume

flow and the targeted temperature increase.

DIELECTRIC STRENGTH

Our PTC registers operate at 230 volts and have a dielectric strength of 500 volts.