Sudden Temperature Drop Anomalies: If the thermocouple electrode wire entirely breaks and opens, the thermostat will immediately activate the thermocouple break protection, causing the temperature display to drop to ambient temperature or even 0°C. Some Husky thermostats will activate the thermocouple break alert, shutting down the output of the appropriate heating channel.
If the thermocouple insulation is broken and grounded, the measured temperature will be continuously low, with the reported value being similar to the ambient temperature, differing from the real temperature of the hot runner by tens to hundreds of degrees.
Over-temperature runaway anomalies: If the thermocouple electrode wire is short-circuited, the thermostat will detect a thermoelectric potential signal that is far lower than the actual temperature. This will constantly cause the heating coil to heat up, eventually resulting in an over-temperature runaway in the hot runner, which can severely burn up the heating coil and the runner plate.
If the thermocouple is connected in reverse, the reverse deviation of the output thermoelectric potential increases as the temperature rises. The thermostat will repeatedly misunderstand insufficient temperature, raise the temperature and activating an over-temperature alert.
Temperature fluctuations and drift anomalies.
Poor contact at thermocouple terminals or intermittent contact owing to a damaged electrode wire can result in erratic temperature swings ranging from ±20℃ and strong oscillations in the temperature controller's control curve.
A considerable decrease in thermocouple insulation resistance causes signal shunting during transmission, resulting in gradual temperature drift. For instance, a measurement of 750℃ may be displayed when the real temperature is 800℃, and the divergence will reoccur soon after calibration.
A damaged thermocouple sheath with internal metal dust and slag can produce an exceptionally quick temperature response, yet the reading varies dramatically and fails to accurately reflect the underlying temperature field.
