PTC specification
The PTC-1k sensor exhibits a sharp rise in temperature when the temperature is close to a certain critical value, and therefore operates as a digital indicator. A gradual temperature signal can, however, not be generated from this PTC.
At room temperature, the PTC has an electrical resistance of around 65 ohms. As the temperature rises up to a critical temperature, the resistance exhibits an almost linear rise up to 1000 ohms. Above this temperature, the resistance rises exponentially. The switching resistance is therefore 1000 ohms. The servo drive will immediately disconnect the power supply if this resistance is exceeded. This makes it possible to guard against overheating the motor. The thermal protection contact cable must therefore be properly connected to the servo drive.
|
Temperature |
Resistance |
|---|---|
|
Up to 20° C below the critical temperature |
< 250 Ω |
|
Up to 5° C below the critical temperature |
< 550 Ω |
|
Switching resistance |
> 1000 Ω |
|
Above the critical temperature |
> 1330 Ω |