Service (User Manual)

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User Manual

• Because of the hygroscopic characteristic of the used ceramic insulation materials they absorb moisture. In order to slow down this process and, at best, to avoid it completely, our heating elements are specially sealed by means of suitable preventive measures. Additionally we send our HotMicroCoil heating elements usually in airtightly sealed plastic bags. If the bags are opened and the heating elements are not used at once, we recommend to repack the elements air-tightly. Despite all preventive measures taken it can occur in single cases, especially after long „open“ storage and in extreme climatic conditions, that the insulation resistance is very low (< 5 MΩ) before initial operation. This might lead to tripping of the residual current circuit breaker, especially in highcavity tools without controlled start-up. It is absolutely important to check the insulation resistance before use and – if necessary – to dry the elements (controlled start-up or drying oven).
• The temperature stress of max. 750 °C on the tube is not valid for the connection area nor brazed heating elements (e.g. HotMicroCoil with Reflection Tube) The latter must not be operated at temperatures higher than 600 °C as this could fuse the braze. The temperatures arising in the connection area determine decisively the suitability of the available terminations.
• The stated nominal voltage must not be exceeded, otherwise overheat is risked. For example, 253 V instead of 230 V (+10%) lead to 21% higher power!
• Generally it can be said: the better heat is carried off, or flows into the work piece respectively, the higher the surface watt density on the sheath can be. When calculating the power, the temperature control and the position of the thermocouple must always be taken into consideration.
• A too slag fit obstructs the heat conduction and leads to heat accumulation that could overheat and eventually destroy the heater.
• Install electric heating elements in systems, machines, and devices in such a way that they are easily accessible at all times and can be easily replaced if necessary. Heating elements are wear parts: they age due to temperature-related structural changes in the heating conductor material and can fail due to operational and application-related influences (e.g., thermal expansion, vibration, corrosion, contact with aggressive media) as well as due to incorrect operation or control errors. In the event of a malfunction, replacement is necessary.
• In every practice application there are working and environmental parameters which cannot be calculated exactly in theory. That is why we recommend generally to test HotMicroCoil elements in the application under real working conditions before series use.



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