If you don't see the above menu, update to
|
 |
| CARTRIDGE HEATERS - HIGH WATT DENSITY WITH TC - RECOMMENDATIONS |
|
 
  |
| IMPORTANT INFORMATION FOR OPTIMAL USE OF HEATERS UTC TYPES 1-2-3-4 | As shown in the drawing above, in heaters with thermocouple UTC 1 and UTC 2 the sensing join of the thermocouple is located at one end of the cartridge, sensibly colder than the body of the cartridge. This causes the thermocouple to sense heat with a certain delay to its production in the heating core of the cartridge.
Therefore, if the heater is controlled by an electronic thermoregulator, great care must be put in setting its switching temperature to avoid burning the heater just because the thermocouple is exposed to heat much later than the central body of the heater.
If the heater is in free air (or in a small metal body with more than 10 W/cm²), it is advisable that the limit temperature is set (at start-up) at values increasing by intervals of, say, 100°C (example: 80°C, 180°C, 280°C, etc., till desired value), with a necessary resting time before re-switching-on at each increase of the limit value. This because of the risk of the heater’s burning before the thermoregulator switching off (for example, the body could go over 1000°C before the thermocouple reaches 500°C).
If the heater is inserted in a greater metallic body, in a hole honed to H7 tolerance, it is possible to directly set the thermoregulator at the target working temperature straight from start-up.
With UTC 3 and UTC 4 heaters the above precautions are normally not necessary.
If the temperature control has a soft-start function, the above precautions can be reduced, nonetheless, trial cycles are always advisable. | |
|
| |
|
|
